diff --git a/mozilla/content/base/public/nsIStyleRuleProcessor.h b/mozilla/content/base/public/nsIStyleRuleProcessor.h
index 78f2f2ab24d..ac4a7517775 100644
--- a/mozilla/content/base/public/nsIStyleRuleProcessor.h
+++ b/mozilla/content/base/public/nsIStyleRuleProcessor.h
@@ -48,7 +48,6 @@
 class nsISizeOfHandler;
 
 class nsIStyleSheet;
-class nsIStyleContext;
 class nsIPresContext;
 class nsIContent;
 class nsIStyledContent;
diff --git a/mozilla/content/base/public/nsIStyleSheet.h b/mozilla/content/base/public/nsIStyleSheet.h
index a31423ebc5c..9e830d71dd3 100644
--- a/mozilla/content/base/public/nsIStyleSheet.h
+++ b/mozilla/content/base/public/nsIStyleSheet.h
@@ -51,7 +51,6 @@ class nsISupportsArray;
 class nsIPresContext;
 class nsIContent;
 class nsIDocument;
-class nsIStyleContext;
 class nsIStyleRuleProcessor;
 
 // IID for the nsIStyleSheet interface {8c4a80a0-ad6a-11d1-8031-006008159b5a}
diff --git a/mozilla/content/base/public/nsIStyledContent.h b/mozilla/content/base/public/nsIStyledContent.h
index 9b9a6f3339e..852c99d74b6 100644
--- a/mozilla/content/base/public/nsIStyledContent.h
+++ b/mozilla/content/base/public/nsIStyledContent.h
@@ -43,7 +43,6 @@
 
 class nsString;
 class nsIStyleRule;
-class nsIStyleContext;
 class nsISupportsArray;
 class nsRuleWalker;
 
diff --git a/mozilla/content/base/src/nsPrintEngine.cpp b/mozilla/content/base/src/nsPrintEngine.cpp
index 39d8afbec3b..5655bfd8e0e 100644
--- a/mozilla/content/base/src/nsPrintEngine.cpp
+++ b/mozilla/content/base/src/nsPrintEngine.cpp
@@ -2585,13 +2585,10 @@ nsPrintEngine::ReflowDocList(nsPrintObject* aPO, PRBool aSetPixelScale, PRBool a
     nsIFrame * frame;
     aPO->mParent->mPresShell->GetPrimaryFrameFor(aPO->mContent, &frame);
     if (frame) {
-      nsCOMPtr<nsIStyleContext> sc;
-      frame->GetStyleContext(getter_AddRefs(sc));
-      if (sc) {
-        const nsStyleVisibility* vis = (const nsStyleVisibility*)sc->GetStyleData(eStyleStruct_Visibility);
-        if (!vis->IsVisible()) {
-          aPO->mDontPrint = PR_TRUE;
-        }
+      const nsStyleVisibility* vis;
+      ::GetStyleData(frame, &vis);
+      if (!vis->IsVisible()) {
+        aPO->mDontPrint = PR_TRUE;
       }
     }
   }
diff --git a/mozilla/content/base/src/nsRuleNode.cpp b/mozilla/content/base/src/nsRuleNode.cpp
index 9d688900ec4..270f7bc6cef 100644
--- a/mozilla/content/base/src/nsRuleNode.cpp
+++ b/mozilla/content/base/src/nsRuleNode.cpp
@@ -52,6 +52,7 @@
 #include "nsThemeConstants.h"
 #include "nsITheme.h"
 #include "pldhash.h"
+#include "nsStyleContext.h"
 
 /*
  * For storage of an |nsRuleNode|'s children in a linked list.
@@ -198,7 +199,7 @@ nsString& Unquote(nsString& aString)
 
 nscoord CalcLength(const nsCSSValue& aValue,
                    const nsFont* aFont, 
-                   nsIStyleContext* aStyleContext,
+                   nsStyleContext* aStyleContext,
                    nsIPresContext* aPresContext,
                    PRBool& aInherited)
 {
@@ -269,7 +270,7 @@ nscoord CalcLength(const nsCSSValue& aValue,
 
 static PRBool SetCoord(const nsCSSValue& aValue, nsStyleCoord& aCoord, 
                        const nsStyleCoord& aParentCoord,
-                       PRInt32 aMask, nsIStyleContext* aStyleContext,
+                       PRInt32 aMask, nsStyleContext* aStyleContext,
                        nsIPresContext* aPresContext, PRBool& aInherited)
 {
   PRBool  result = PR_TRUE;
@@ -1207,7 +1208,7 @@ nsRuleNode::CheckSpecifiedProperties(const nsStyleStructID aSID,
 }
 
 const nsStyleStruct*
-nsRuleNode::GetDisplayData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetDisplayData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataDisplay displayData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Display, mPresContext, aContext);
@@ -1221,7 +1222,7 @@ nsRuleNode::GetDisplayData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetVisibilityData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetVisibilityData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataDisplay displayData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Visibility, mPresContext, aContext);
@@ -1231,7 +1232,7 @@ nsRuleNode::GetVisibilityData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetTextData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetTextData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataText textData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Text, mPresContext, aContext);
@@ -1241,7 +1242,7 @@ nsRuleNode::GetTextData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetTextResetData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetTextResetData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataText textData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_TextReset, mPresContext, aContext);
@@ -1251,7 +1252,7 @@ nsRuleNode::GetTextResetData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetUserInterfaceData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetUserInterfaceData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataUserInterface uiData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_UserInterface, mPresContext, aContext);
@@ -1263,7 +1264,7 @@ nsRuleNode::GetUserInterfaceData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetUIResetData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetUIResetData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataUserInterface uiData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_UIReset, mPresContext, aContext);
@@ -1275,7 +1276,7 @@ nsRuleNode::GetUIResetData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetFontData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetFontData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataFont fontData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Font, mPresContext, aContext);
@@ -1285,7 +1286,7 @@ nsRuleNode::GetFontData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetColorData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetColorData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataColor colorData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Color, mPresContext, aContext);
@@ -1295,7 +1296,7 @@ nsRuleNode::GetColorData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetBackgroundData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetBackgroundData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataColor colorData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Background, mPresContext, aContext);
@@ -1305,7 +1306,7 @@ nsRuleNode::GetBackgroundData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetMarginData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetMarginData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataMargin marginData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Margin, mPresContext, aContext);
@@ -1321,7 +1322,7 @@ nsRuleNode::GetMarginData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetBorderData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetBorderData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataMargin marginData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Border, mPresContext, aContext);
@@ -1351,7 +1352,7 @@ nsRuleNode::GetBorderData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetPaddingData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetPaddingData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataMargin marginData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Padding, mPresContext, aContext);
@@ -1367,7 +1368,7 @@ nsRuleNode::GetPaddingData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetOutlineData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetOutlineData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataMargin marginData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Outline, mPresContext, aContext);
@@ -1383,7 +1384,7 @@ nsRuleNode::GetOutlineData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetListData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetListData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataList listData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_List, mPresContext, aContext);
@@ -1398,7 +1399,7 @@ nsRuleNode::GetListData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetPositionData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetPositionData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataPosition posData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Position, mPresContext, aContext);
@@ -1413,7 +1414,7 @@ nsRuleNode::GetPositionData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetTableData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetTableData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataTable tableData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Table, mPresContext, aContext);
@@ -1423,7 +1424,7 @@ nsRuleNode::GetTableData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetTableBorderData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetTableBorderData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataTable tableData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_TableBorder, mPresContext, aContext);
@@ -1433,7 +1434,7 @@ nsRuleNode::GetTableBorderData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetContentData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetContentData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataContent contentData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Content, mPresContext, aContext);
@@ -1446,7 +1447,7 @@ nsRuleNode::GetContentData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetQuotesData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetQuotesData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataContent contentData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Quotes, mPresContext, aContext);
@@ -1459,7 +1460,7 @@ nsRuleNode::GetQuotesData(nsIStyleContext* aContext, PRBool aComputeData)
 
 #ifdef INCLUDE_XUL
 const nsStyleStruct*
-nsRuleNode::GetXULData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetXULData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataXUL xulData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_XUL, mPresContext, aContext);
@@ -1471,7 +1472,7 @@ nsRuleNode::GetXULData(nsIStyleContext* aContext, PRBool aComputeData)
 
 #ifdef MOZ_SVG
 const nsStyleStruct*
-nsRuleNode::GetSVGData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetSVGData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataSVG svgData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_SVG, mPresContext, aContext);
@@ -1483,7 +1484,7 @@ nsRuleNode::GetSVGData(nsIStyleContext* aContext, PRBool aComputeData)
 
 const nsStyleStruct*
 nsRuleNode::WalkRuleTree(const nsStyleStructID aSID,
-                         nsIStyleContext* aContext, 
+                         nsStyleContext* aContext, 
                          nsRuleData* aRuleData,
                          nsRuleDataStruct* aSpecificData,
                          PRBool aComputeData)
@@ -1591,7 +1592,7 @@ nsRuleNode::WalkRuleTree(const nsStyleStructID aSID,
     // All information must necessarily be inherited from our parent style context.
     // In the absence of any computed data in the rule tree and with
     // no rules specified that didn't have values of 'inherit', we should check our parent.
-    nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+    nsStyleContext* parentContext = aContext->GetParent();
     if (parentContext) {
       // We have a parent, and so we should just inherit from the parent.
       // Set the inherit bits on our context.  These bits tell the style context that
@@ -1654,7 +1655,7 @@ IsChrome(nsIPresContext* aPresContext)
 }
 
 const nsStyleStruct*
-nsRuleNode::SetDefaultOnRoot(const nsStyleStructID aSID, nsIStyleContext* aContext)
+nsRuleNode::SetDefaultOnRoot(const nsStyleStructID aSID, nsStyleContext* aContext)
 {
   switch (aSID) {
     case eStyleStruct_Font: 
@@ -1817,7 +1818,7 @@ nsRuleNode::gComputeStyleDataFn[] = {
 };
 
 static void
-SetFont(nsIPresContext* aPresContext, nsIStyleContext* aContext,
+SetFont(nsIPresContext* aPresContext, nsStyleContext* aContext,
         nscoord aMinFontSize, PRBool aUseDocumentFonts, PRBool aChromeOverride,
         PRBool aIsGeneric, const nsRuleDataFont& aFontData,
         const nsFont& aDefaultFont, const nsStyleFont* aParentFont,
@@ -2106,14 +2107,14 @@ SetFont(nsIPresContext* aPresContext, nsIStyleContext* aContext,
 //    up to the root where default values come from the presentation context)
 //  - re-apply cascading rules from there without caching intermediate values
 static void
-SetGenericFont(nsIPresContext* aPresContext, nsIStyleContext* aContext,
+SetGenericFont(nsIPresContext* aPresContext, nsStyleContext* aContext,
                const nsRuleDataFont& aFontData, PRUint8 aGenericFontID,
                nscoord aMinFontSize, PRBool aUseDocumentFonts,
                PRBool aChromeOverride, nsStyleFont* aFont)
 {
   // walk up the contexts until a context with the desired generic font
   nsAutoVoidArray contextPath;
-  nsCOMPtr<nsIStyleContext> higherContext = aContext->GetParent();
+  nsStyleContext* higherContext = aContext->GetParent();
   while (higherContext) {
     contextPath.AppendElement(higherContext);
     const nsStyleFont* higherFont = (const nsStyleFont*)higherContext->GetStyleData(eStyleStruct_Font);
@@ -2135,7 +2136,7 @@ SetGenericFont(nsIPresContext* aPresContext, nsIStyleContext* aContext,
   PRInt32 i = contextPath.Count() - 1;
   PRBool zoom = PR_TRUE;
   if (higherContext) {
-    nsIStyleContext* context = (nsIStyleContext*)contextPath[i];
+    nsStyleContext* context = (nsStyleContext*)contextPath[i];
     nsStyleFont* tmpFont = (nsStyleFont*)context->GetStyleData(eStyleStruct_Font);
     parentFont.mFlags = tmpFont->mFlags;
     parentFont.mFont = tmpFont->mFont;
@@ -2155,7 +2156,7 @@ SetGenericFont(nsIPresContext* aPresContext, nsIStyleContext* aContext,
   nsCOMPtr<nsIStyleRule> rule;
 
   for (; i >= 0; --i) {
-    nsIStyleContext* context = (nsIStyleContext*)contextPath[i];
+    nsStyleContext* context = (nsStyleContext*)contextPath[i];
     nsRuleDataFont fontData; // Declare a struct with null CSS values.
     nsRuleData ruleData(eStyleStruct_Font, aPresContext, context);
     ruleData.mFontData = &fontData;
@@ -2203,11 +2204,11 @@ SetGenericFont(nsIPresContext* aPresContext, nsIStyleContext* aContext,
 const nsStyleStruct* 
 nsRuleNode::ComputeFontData(nsStyleStruct* aStartStruct,
                             const nsRuleDataStruct& aData, 
-                            nsIStyleContext* aContext, 
+                            nsStyleContext* aContext, 
                             nsRuleNode* aHighestNode,
                             const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
 
   const nsRuleDataFont& fontData = NS_STATIC_CAST(const nsRuleDataFont&, aData);
   nsStyleFont* font = nsnull;
@@ -2333,11 +2334,11 @@ nsRuleNode::ComputeFontData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputeTextData(nsStyleStruct* aStartStruct,
                             const nsRuleDataStruct& aData, 
-                            nsIStyleContext* aContext, 
+                            nsStyleContext* aContext, 
                             nsRuleNode* aHighestNode,
                             const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
 
   const nsRuleDataText& textData = NS_STATIC_CAST(const nsRuleDataText&, aData);
   nsStyleText* text = nsnull;
@@ -2454,11 +2455,11 @@ nsRuleNode::ComputeTextData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputeTextResetData(nsStyleStruct* aStartData,
                                  const nsRuleDataStruct& aData, 
-                                 nsIStyleContext* aContext, 
+                                 nsStyleContext* aContext, 
                                  nsRuleNode* aHighestNode,
                                  const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
 
   const nsRuleDataText& textData = NS_STATIC_CAST(const nsRuleDataText&, aData);
   nsStyleTextReset* text;
@@ -2537,12 +2538,12 @@ nsRuleNode::ComputeTextResetData(nsStyleStruct* aStartData,
 const nsStyleStruct*
 nsRuleNode::ComputeUserInterfaceData(nsStyleStruct* aStartData,
                                      const nsRuleDataStruct& aData, 
-                                     nsIStyleContext* aContext, 
+                                     nsStyleContext* aContext, 
                                      nsRuleNode* aHighestNode,
                                      const RuleDetail& aRuleDetail,
                                      PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataUserInterface& uiData = NS_STATIC_CAST(const nsRuleDataUserInterface&, aData);
   nsStyleUserInterface* ui = nsnull;
@@ -2649,11 +2650,11 @@ nsRuleNode::ComputeUserInterfaceData(nsStyleStruct* aStartData,
 const nsStyleStruct*
 nsRuleNode::ComputeUIResetData(nsStyleStruct* aStartData,
                                const nsRuleDataStruct& aData, 
-                               nsIStyleContext* aContext, 
+                               nsStyleContext* aContext, 
                                nsRuleNode* aHighestNode,
                                const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataUserInterface& uiData = NS_STATIC_CAST(const nsRuleDataUserInterface&, aData);
   nsStyleUIReset* ui;
@@ -2739,11 +2740,11 @@ nsRuleNode::ComputeUIResetData(nsStyleStruct* aStartData,
 const nsStyleStruct*
 nsRuleNode::ComputeDisplayData(nsStyleStruct* aStartStruct,
                                const nsRuleDataStruct& aData, 
-                               nsIStyleContext* aContext, 
+                               nsStyleContext* aContext, 
                                nsRuleNode* aHighestNode,
                                const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataDisplay& displayData = NS_STATIC_CAST(const nsRuleDataDisplay&, aData);
   nsStyleDisplay* display;
@@ -2755,8 +2756,7 @@ nsRuleNode::ComputeDisplayData(nsStyleStruct* aStartStruct,
     display = new (mPresContext) nsStyleDisplay();
   const nsStyleDisplay* parentDisplay = display;
 
-  nsCOMPtr<nsIAtom> pseudoTag;
-  aContext->GetPseudoType(*getter_AddRefs(pseudoTag));
+  nsCOMPtr<nsIAtom> pseudoTag = aContext->GetPseudoType();
   PRBool generatedContent = (pseudoTag == nsCSSPseudoElements::before || 
                              pseudoTag == nsCSSPseudoElements::after);
 
@@ -2998,11 +2998,11 @@ nsRuleNode::ComputeDisplayData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputeVisibilityData(nsStyleStruct* aStartStruct,
                                   const nsRuleDataStruct& aData, 
-                                  nsIStyleContext* aContext, 
+                                  nsStyleContext* aContext, 
                                   nsRuleNode* aHighestNode,
                                   const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataDisplay& displayData = NS_STATIC_CAST(const nsRuleDataDisplay&, aData);
   nsStyleVisibility* visibility = nsnull;
@@ -3107,11 +3107,11 @@ nsRuleNode::ComputeVisibilityData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputeColorData(nsStyleStruct* aStartStruct,
                              const nsRuleDataStruct& aData, 
-                             nsIStyleContext* aContext, 
+                             nsStyleContext* aContext, 
                              nsRuleNode* aHighestNode,
                              const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataColor& colorData = NS_STATIC_CAST(const nsRuleDataColor&, aData);
   nsStyleColor* color = nsnull;
@@ -3164,11 +3164,11 @@ nsRuleNode::ComputeColorData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputeBackgroundData(nsStyleStruct* aStartStruct,
                                   const nsRuleDataStruct& aData, 
-                                  nsIStyleContext* aContext, 
+                                  nsStyleContext* aContext, 
                                   nsRuleNode* aHighestNode,
                                   const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataColor& colorData = NS_STATIC_CAST(const nsRuleDataColor&, aData);
   nsStyleBackground* bg;
@@ -3354,11 +3354,11 @@ static const CSSRectSide gCSSSides[] = {
 const nsStyleStruct*
 nsRuleNode::ComputeMarginData(nsStyleStruct* aStartStruct,
                               const nsRuleDataStruct& aData, 
-                              nsIStyleContext* aContext, 
+                              nsStyleContext* aContext, 
                               nsRuleNode* aHighestNode,
                               const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataMargin& marginData = NS_STATIC_CAST(const nsRuleDataMargin&, aData);
   nsStyleMargin* margin;
@@ -3411,11 +3411,11 @@ nsRuleNode::ComputeMarginData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeBorderData(nsStyleStruct* aStartStruct,
                               const nsRuleDataStruct& aData, 
-                              nsIStyleContext* aContext, 
+                              nsStyleContext* aContext, 
                               nsRuleNode* aHighestNode,
                               const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataMargin& marginData = NS_STATIC_CAST(const nsRuleDataMargin&, aData);
   nsStyleBorder* border;
@@ -3517,7 +3517,7 @@ nsRuleNode::ComputeBorderData(nsStyleStruct* aStartStruct,
           // computed (unlike for the element where this will be used, for
           // which the color could be specified on a more specific rule).
           const nsStyleColor *parentColor;
-          ::GetStyleData(parentContext.get(), &parentColor);
+          ::GetStyleData(parentContext, &parentColor);
           border->SetBorderColor(side, parentColor->mColor);
         } else
           border->SetBorderColor(side, borderColor);
@@ -3579,11 +3579,11 @@ nsRuleNode::ComputeBorderData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputePaddingData(nsStyleStruct* aStartStruct,
                                const nsRuleDataStruct& aData, 
-                               nsIStyleContext* aContext, 
+                               nsStyleContext* aContext, 
                                nsRuleNode* aHighestNode,
                                const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataMargin& marginData = NS_STATIC_CAST(const nsRuleDataMargin&, aData);
   nsStylePadding* padding;
@@ -3636,11 +3636,11 @@ nsRuleNode::ComputePaddingData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputeOutlineData(nsStyleStruct* aStartStruct,
                                const nsRuleDataStruct& aData, 
-                               nsIStyleContext* aContext, 
+                               nsStyleContext* aContext, 
                                nsRuleNode* aHighestNode,
                                const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataMargin& marginData = NS_STATIC_CAST(const nsRuleDataMargin&, aData);
   nsStyleOutline* outline;
@@ -3709,11 +3709,11 @@ nsRuleNode::ComputeOutlineData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeListData(nsStyleStruct* aStartStruct,
                             const nsRuleDataStruct& aData, 
-                            nsIStyleContext* aContext, 
+                            nsStyleContext* aContext, 
                             nsRuleNode* aHighestNode,
                             const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataList& listData = NS_STATIC_CAST(const nsRuleDataList&, aData);
   nsStyleList* list = nsnull;
@@ -3826,11 +3826,11 @@ nsRuleNode::ComputeListData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputePositionData(nsStyleStruct* aStartStruct,
                                 const nsRuleDataStruct& aData, 
-                                nsIStyleContext* aContext, 
+                                nsStyleContext* aContext, 
                                 nsRuleNode* aHighestNode,
                                 const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataPosition& posData = NS_STATIC_CAST(const nsRuleDataPosition&, aData);
   nsStylePosition* pos;
@@ -3935,11 +3935,11 @@ nsRuleNode::ComputePositionData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeTableData(nsStyleStruct* aStartStruct,
                              const nsRuleDataStruct& aData, 
-                             nsIStyleContext* aContext, 
+                             nsStyleContext* aContext, 
                              nsRuleNode* aHighestNode,
                              const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataTable& tableData = NS_STATIC_CAST(const nsRuleDataTable&, aData);
   nsStyleTable* table;
@@ -4006,11 +4006,11 @@ nsRuleNode::ComputeTableData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeTableBorderData(nsStyleStruct* aStartStruct,
                                    const nsRuleDataStruct& aData, 
-                                   nsIStyleContext* aContext, 
+                                   nsStyleContext* aContext, 
                                    nsRuleNode* aHighestNode,
                                    const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataTable& tableData = NS_STATIC_CAST(const nsRuleDataTable&, aData);
   nsStyleTableBorder* table = nsnull;
@@ -4105,11 +4105,11 @@ nsRuleNode::ComputeTableBorderData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeContentData(nsStyleStruct* aStartStruct,
                                const nsRuleDataStruct& aData, 
-                               nsIStyleContext* aContext, 
+                               nsStyleContext* aContext, 
                                nsRuleNode* aHighestNode,
                                const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataContent& contentData = NS_STATIC_CAST(const nsRuleDataContent&, aData);
   nsStyleContent* content;
@@ -4301,11 +4301,11 @@ nsRuleNode::ComputeContentData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeQuotesData(nsStyleStruct* aStartStruct,
                               const nsRuleDataStruct& aData, 
-                              nsIStyleContext* aContext, 
+                              nsStyleContext* aContext, 
                               nsRuleNode* aHighestNode,
                               const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataContent& contentData = NS_STATIC_CAST(const nsRuleDataContent&, aData);
   nsStyleQuotes* quotes = nsnull;
@@ -4395,11 +4395,11 @@ nsRuleNode::ComputeQuotesData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeXULData(nsStyleStruct* aStartStruct,
                            const nsRuleDataStruct& aData, 
-                           nsIStyleContext* aContext, 
+                           nsStyleContext* aContext, 
                            nsRuleNode* aHighestNode,
                            const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataXUL& xulData = NS_STATIC_CAST(const nsRuleDataXUL&, aData);
   nsStyleXUL* xul = nsnull;
@@ -4517,7 +4517,7 @@ SetSVGOpacity(const nsCSSValue& aValue, float parentOpacity, float& opacity, PRB
 
 static void
 SetSVGLength(const nsCSSValue& aValue, float parentLength, float& length,
-             nsIStyleContext* aContext, nsIPresContext* aPresContext, PRBool& aInherited)
+             nsStyleContext* aContext, nsIPresContext* aPresContext, PRBool& aInherited)
 {
   nsStyleCoord coord;
   PRBool dummy;
@@ -4545,11 +4545,11 @@ SetSVGLength(const nsCSSValue& aValue, float parentLength, float& length,
 const nsStyleStruct* 
 nsRuleNode::ComputeSVGData(nsStyleStruct* aStartStruct,
                            const nsRuleDataStruct& aData, 
-                           nsIStyleContext* aContext, 
+                           nsStyleContext* aContext, 
                            nsRuleNode* aHighestNode,
                            const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
 
   nsStyleSVG* svg = nsnull;
   nsStyleSVG* parentSVG = svg;
@@ -4692,7 +4692,7 @@ nsRuleNode::gGetStyleDataFn[] = {
 
 const nsStyleStruct* 
 nsRuleNode::GetStyleData(nsStyleStructID aSID, 
-                         nsIStyleContext* aContext,
+                         nsStyleContext* aContext,
                          PRBool aComputeData)
 {
   const nsStyleStruct* cachedData = mStyleData.GetStyleData(aSID);
diff --git a/mozilla/content/base/src/nsStyleContext.cpp b/mozilla/content/base/src/nsStyleContext.cpp
index 13428a4cd56..ed785cfac24 100644
--- a/mozilla/content/base/src/nsStyleContext.cpp
+++ b/mozilla/content/base/src/nsStyleContext.cpp
@@ -54,6 +54,7 @@
 
 #include "nsRuleNode.h"
 #include "nsUnitConversion.h"
+#include "nsStyleContext.h"
 
 #ifdef DEBUG
 // #define NOISY_DEBUG
@@ -61,87 +62,8 @@
 
 //----------------------------------------------------------------------
 
-class nsStyleContext : public nsIStyleContext 
-{
-public:
-  nsStyleContext(nsIStyleContext* aParent, nsIAtom* aPseudoTag, 
-                 nsRuleNode* aRuleNode, nsIPresContext* aPresContext);
-  virtual ~nsStyleContext();
 
-  void* operator new(size_t sz, nsIPresContext* aPresContext) CPP_THROW_NEW;
-  void Destroy();
-
-  NS_DECL_ISUPPORTS
-
-  virtual already_AddRefed<nsIStyleContext> GetParent(void) const;
-  NS_IMETHOD GetFirstChild(nsIStyleContext** aContext);
-
-  NS_IMETHOD GetPseudoType(nsIAtom*& aPseudoTag) const;
-
-  NS_IMETHOD FindChildWithRules(const nsIAtom* aPseudoTag, nsRuleNode* aRules,
-                                nsIStyleContext*& aResult);
-
-  virtual PRBool    Equals(const nsIStyleContext* aOther) const;
-  virtual PRBool    HasTextDecorations() { return mBits & NS_STYLE_HAS_TEXT_DECORATIONS; };
-
-  NS_IMETHOD GetBorderPaddingFor(nsStyleBorderPadding& aBorderPadding);
-
-  NS_IMETHOD GetStyle(nsStyleStructID aSID, const nsStyleStruct** aStruct);
-  NS_IMETHOD SetStyle(nsStyleStructID aSID, nsStyleStruct* aStruct);
-
-  NS_IMETHOD GetRuleNode(nsRuleNode** aResult) { *aResult = mRuleNode; return NS_OK; };
-  NS_IMETHOD AddStyleBit(const PRUint32& aBit) { mBits |= aBit; return NS_OK; };
-  NS_IMETHOD GetStyleBits(PRUint32* aBits) { *aBits = mBits; return NS_OK; };
-
-  virtual const nsStyleStruct* GetStyleData(nsStyleStructID aSID);
-  const nsStyleStruct* PeekStyleData(nsStyleStructID aSID);
-
-  virtual nsStyleStruct* GetUniqueStyleData(nsIPresContext* aPresContext, const nsStyleStructID& aSID);
-
-  virtual nsresult ClearCachedDataForRule(nsIStyleRule* aRule);
-
-  virtual nsresult ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule);
-
-  NS_IMETHOD  CalcStyleDifference(nsIStyleContext* aOther, nsChangeHint& aHint);
-
-#ifdef DEBUG
-  virtual void DumpRegressionData(nsIPresContext* aPresContext, FILE* out, PRInt32 aIndent);
-
-  virtual void List(FILE* out, PRInt32 aIndent);
-
-  virtual void SizeOf(nsISizeOfHandler *aSizeOfHandler, PRUint32 &aSize);
-#endif
-
-protected:
-  void AppendChild(nsStyleContext* aChild);
-  void RemoveChild(nsStyleContext* aChild);
-
-  void ApplyStyleFixups(nsIPresContext* aPresContext);
-
-  nsStyleContext* mParent;
-  nsStyleContext* mChild;
-  nsStyleContext* mEmptyChild;
-  nsStyleContext* mPrevSibling;
-  nsStyleContext* mNextSibling;
-
-  // If this style context is for a pseudo-element, the pseudo-element
-  // atom.  Otherwise, null.
-  nsCOMPtr<nsIAtom> mPseudoTag;
-
-  nsRuleNode*             mRuleNode;
-
-  // |mCachedStyleData| points to both structs that are owned by this
-  // style context and structs that are owned by one of this style
-  // context's ancestors (which are indirectly owned since this style
-  // context owns a reference to its parent).  If the bit in |mBits| is
-  // set for a struct, that means that the pointer for that struct is
-  // owned by an ancestor rather than by this style context.
-  nsCachedStyleData       mCachedStyleData; // Our cached style data.
-  PRUint32                mBits; // Which structs are inherited from the
-                                 // parent context.
-};
-
-nsStyleContext::nsStyleContext(nsIStyleContext* aParent,
+nsStyleContext::nsStyleContext(nsStyleContext* aParent,
                                nsIAtom* aPseudoTag,
                                nsRuleNode* aRuleNode,
                                nsIPresContext* aPresContext)
@@ -150,13 +72,13 @@ nsStyleContext::nsStyleContext(nsIStyleContext* aParent,
     mEmptyChild(nsnull),
     mPseudoTag(aPseudoTag),
     mRuleNode(aRuleNode),
-    mBits(0)
+    mBits(0),
+    mRefCnt(0)
 {
-  
   mNextSibling = this;
   mPrevSibling = this;
   if (mParent) {
-    NS_ADDREF(mParent);
+    mParent->AddRef();
     mParent->AppendChild(this);
   }
 
@@ -173,7 +95,7 @@ nsStyleContext::~nsStyleContext()
 
   if (mParent) {
     mParent->RemoveChild(this);
-    NS_RELEASE(mParent);
+    mParent->Release();
   }
 
   // Free up our data structs.
@@ -184,24 +106,6 @@ nsStyleContext::~nsStyleContext()
   }
 }
 
-NS_IMPL_ADDREF(nsStyleContext)
-NS_IMPL_RELEASE_WITH_DESTROY(nsStyleContext, Destroy())
-NS_IMPL_QUERY_INTERFACE1(nsStyleContext, nsIStyleContext)
-
-already_AddRefed<nsIStyleContext> nsStyleContext::GetParent(void) const
-{
-  NS_IF_ADDREF(mParent);
-  return mParent;
-}
-
-NS_IMETHODIMP
-nsStyleContext::GetFirstChild(nsIStyleContext** aContext)
-{
-  *aContext = mChild;
-  NS_IF_ADDREF(*aContext);
-  return NS_OK;
-}
-
 void nsStyleContext::AppendChild(nsStyleContext* aChild)
 {
   if (aChild->mRuleNode->IsRoot()) {
@@ -263,23 +167,22 @@ void nsStyleContext::RemoveChild(nsStyleContext* aChild)
   aChild->mPrevSibling = aChild;
 }
 
-NS_IMETHODIMP
-nsStyleContext::GetPseudoType(nsIAtom*& aPseudoTag) const
+already_AddRefed<nsIAtom>
+nsStyleContext::GetPseudoType() const
 {
-  aPseudoTag = mPseudoTag;
-  NS_IF_ADDREF(aPseudoTag);
-  return NS_OK;
+  nsIAtom* pseudoTag = mPseudoTag;
+  NS_IF_ADDREF(pseudoTag);
+  return pseudoTag;
 }
 
-NS_IMETHODIMP
+already_AddRefed<nsStyleContext>
 nsStyleContext::FindChildWithRules(const nsIAtom* aPseudoTag, 
-                                     nsRuleNode* aRuleNode,
-                                     nsIStyleContext*& aResult)
+                                   nsRuleNode* aRuleNode)
 {
   PRUint32 threshold = 10; // The # of siblings we're willing to examine
                            // before just giving this whole thing up.
 
-  aResult = nsnull;
+  nsStyleContext* aResult = nsnull;
 
   if ((nsnull != mChild) || (nsnull != mEmptyChild)) {
     nsStyleContext* child;
@@ -313,12 +216,15 @@ nsStyleContext::FindChildWithRules(const nsIAtom* aPseudoTag,
       } while (child != mChild);
     }
   }
-  NS_IF_ADDREF(aResult);
-  return NS_OK;
+
+  if (aResult)
+    aResult->AddRef();
+
+  return aResult;
 }
 
 
-PRBool nsStyleContext::Equals(const nsIStyleContext* aOther) const
+PRBool nsStyleContext::Equals(const nsStyleContext* aOther) const
 {
   PRBool  result = PR_TRUE;
   const nsStyleContext* other = (nsStyleContext*)aOther;
@@ -358,7 +264,7 @@ inline const nsStyleStruct* nsStyleContext::PeekStyleData(nsStyleStructID aSID)
   return mRuleNode->GetStyleData(aSID, this, PR_FALSE); // Our rule node will take care of it for us.
 }
 
-NS_IMETHODIMP
+void
 nsStyleContext::GetBorderPaddingFor(nsStyleBorderPadding& aBorderPadding)
 {
   nsMargin border, padding;
@@ -370,8 +276,6 @@ nsStyleContext::GetBorderPaddingFor(nsStyleBorderPadding& aBorderPadding)
       aBorderPadding.SetBorderPadding(border);
     }
   }
-
-  return NS_OK;
 }
 
 // This is an evil evil function, since it forces you to alloc your own separate copy of
@@ -421,14 +325,7 @@ nsStyleContext::GetUniqueStyleData(nsIPresContext* aPresContext, const nsStyleSt
   return result;
 }
 
-NS_IMETHODIMP
-nsStyleContext::GetStyle(nsStyleStructID aSID, const nsStyleStruct** aStruct)
-{
-  *aStruct = GetStyleData(aSID);
-  return NS_OK;
-}
-
-NS_IMETHODIMP
+void
 nsStyleContext::SetStyle(nsStyleStructID aSID, nsStyleStruct* aStruct)
 {
   // This method should only be called from nsRuleNode!  It is not a public
@@ -461,8 +358,6 @@ nsStyleContext::SetStyle(nsStyleStructID aSID, nsStyleStruct* aStruct)
   }
   char* dataSlot = resetOrInherit + info.mInheritResetOffset;
   *NS_REINTERPRET_CAST(nsStyleStruct**, dataSlot) = aStruct;
-
-  return NS_OK;
 }
 
 void
@@ -497,7 +392,7 @@ nsStyleContext::ApplyStyleFixups(nsIPresContext* aPresContext)
   }
 }
 
-nsresult
+void
 nsStyleContext::ClearCachedDataForRule(nsIStyleRule* aInlineStyleRule)
 {
   mRuleNode->ClearCachedData(aInlineStyleRule); // XXXdwh.  If we're willing to *really* special case
@@ -505,10 +400,9 @@ nsStyleContext::ClearCachedDataForRule(nsIStyleRule* aInlineStyleRule)
                                            // that actually changed.  For example, if someone changes
                                            // style.left, we really only need to blow away cached
                                            // data in the position struct.
-  return NS_OK;
 }
 
-nsresult
+void
 nsStyleContext::ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule)
 {
   PRBool matched = PR_TRUE;
@@ -541,13 +435,12 @@ nsStyleContext::ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule
       child = child->mNextSibling;
     } while (mEmptyChild != child);
   }
-
-  return NS_OK;
 }
 
-NS_IMETHODIMP
-nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, nsChangeHint& aHint)
+nsChangeHint
+nsStyleContext::CalcStyleDifference(nsStyleContext* aOther)
 {
+  nsChangeHint hint = NS_STYLE_HINT_NONE;
   if (aOther) {
     // If our rule nodes are the same, then we are looking at the same style
     // data.  We know this because CalcStyleDifference is always called on two
@@ -557,72 +450,70 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, nsChangeHint& aHint
     nsRuleNode* ruleNode;
     aOther->GetRuleNode(&ruleNode);
     if (ruleNode == mRuleNode)
-      return NS_OK;
+      return hint;
 
     nsChangeHint maxHint = NS_STYLE_HINT_FRAMECHANGE;
     
     // We begin by examining those style structs that are capable of causing the maximal
     // difference, a FRAMECHANGE.
     // FRAMECHANGE Structs: Display, XUL, Content, UserInterface, Visibility, Quotes
-    if (!NS_IsHintSubset(maxHint, aHint)) {
-      const nsStyleDisplay* display = (const nsStyleDisplay*)PeekStyleData(eStyleStruct_Display);
-      if (display) {
-        const nsStyleDisplay* otherDisplay = (const nsStyleDisplay*)aOther->GetStyleData(eStyleStruct_Display);
-        if (display != otherDisplay) {
-          NS_UpdateHint(aHint, display->CalcDifference(*otherDisplay));
-        }
+    const nsStyleDisplay* display = (const nsStyleDisplay*)PeekStyleData(eStyleStruct_Display);
+    if (display) {
+      const nsStyleDisplay* otherDisplay = (const nsStyleDisplay*)aOther->GetStyleData(eStyleStruct_Display);
+      if (display != otherDisplay) {
+        NS_UpdateHint(hint, display->CalcDifference(*otherDisplay));
       }
     }
 
 #ifdef INCLUDE_XUL
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleXUL* xul = (const nsStyleXUL*)PeekStyleData(eStyleStruct_XUL);
       if (xul) {
         const nsStyleXUL* otherXUL = (const nsStyleXUL*)aOther->GetStyleData(eStyleStruct_XUL);
         if (xul != otherXUL) {
-          NS_UpdateHint(aHint, xul->CalcDifference(*otherXUL));
+          NS_UpdateHint(hint, xul->CalcDifference(*otherXUL));
         }
       }
     }
 #endif
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleContent* content = (const nsStyleContent*)PeekStyleData(eStyleStruct_Content);
       if (content) {
         const nsStyleContent* otherContent = (const nsStyleContent*)aOther->GetStyleData(eStyleStruct_Content);
         if (content != otherContent) {
-          NS_UpdateHint(aHint, content->CalcDifference(*otherContent));
+          NS_UpdateHint(hint, content->CalcDifference(*otherContent));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleUserInterface* ui = (const nsStyleUserInterface*)PeekStyleData(eStyleStruct_UserInterface);
       if (ui) {
         const nsStyleUserInterface* otherUI = (const nsStyleUserInterface*)aOther->GetStyleData(eStyleStruct_UserInterface);
         if (ui != otherUI) {
-          NS_UpdateHint(aHint, ui->CalcDifference(*otherUI));
+          NS_UpdateHint(hint, ui->CalcDifference(*otherUI));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleVisibility* vis = (const nsStyleVisibility*)PeekStyleData(eStyleStruct_Visibility);
       if (vis) {
         const nsStyleVisibility* otherVis = (const nsStyleVisibility*)aOther->GetStyleData(eStyleStruct_Visibility);
         if (vis != otherVis) {
-          NS_UpdateHint(aHint, vis->CalcDifference(*otherVis));
+          NS_UpdateHint(hint, vis->CalcDifference(*otherVis));
         }
       }
     }
 
 #ifdef MOZ_SVG
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleSVG* svg = (const nsStyleSVG*)PeekStyleData(eStyleStruct_SVG);
       if (svg) {
         const nsStyleSVG* otherSVG = (const nsStyleSVG*)aOther->GetStyleData(eStyleStruct_SVG);
         if (svg != otherSVG) {
-          NS_UpdateHint(aHint, svg->CalcDifference(*otherSVG));
+          NS_UpdateHint(hint, svg->CalcDifference(*otherSVG));
         }
       }
     }
@@ -630,12 +521,12 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, nsChangeHint& aHint
 
     // If the quotes implementation is ever going to change we might not need
     // a framechange here and a reflow should be sufficient.  See bug 35768.
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleQuotes* quotes = (const nsStyleQuotes*)PeekStyleData(eStyleStruct_Quotes);
       if (quotes) {
         const nsStyleQuotes* otherQuotes = (const nsStyleQuotes*)aOther->GetStyleData(eStyleStruct_Quotes);
         if (quotes != otherQuotes) {
-          NS_UpdateHint(aHint, quotes->CalcDifference(*otherQuotes));
+          NS_UpdateHint(hint, quotes->CalcDifference(*otherQuotes));
         }
       }
     }
@@ -646,102 +537,102 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, nsChangeHint& aHint
     // The following structs cause (as their maximal difference) a reflow to occur.
     // REFLOW Structs: Font, Margin, Padding, Border, List, Position, Text, TextReset,
     // Table, TableBorder
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleFont* font = (const nsStyleFont*)PeekStyleData(eStyleStruct_Font);
       if (font) {
         const nsStyleFont* otherFont = (const nsStyleFont*)aOther->GetStyleData(eStyleStruct_Font);
         if (font != otherFont) {
-          NS_UpdateHint(aHint, font->CalcDifference(*otherFont));
+          NS_UpdateHint(hint, font->CalcDifference(*otherFont));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleMargin* margin = (const nsStyleMargin*)PeekStyleData(eStyleStruct_Margin);
       if (margin) {
         const nsStyleMargin* otherMargin = (const nsStyleMargin*)aOther->GetStyleData(eStyleStruct_Margin);
         if (margin != otherMargin) {
-          NS_UpdateHint(aHint, margin->CalcDifference(*otherMargin));
+          NS_UpdateHint(hint, margin->CalcDifference(*otherMargin));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStylePadding* padding = (const nsStylePadding*)PeekStyleData(eStyleStruct_Padding);
       if (padding) {
         const nsStylePadding* otherPadding = (const nsStylePadding*)aOther->GetStyleData(eStyleStruct_Padding);
         if (padding != otherPadding) {
-          NS_UpdateHint(aHint, padding->CalcDifference(*otherPadding));
+          NS_UpdateHint(hint, padding->CalcDifference(*otherPadding));
         }
       }
     }
     
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleBorder* border = (const nsStyleBorder*)PeekStyleData(eStyleStruct_Border);
       if (border) {
         const nsStyleBorder* otherBorder = (const nsStyleBorder*)aOther->GetStyleData(eStyleStruct_Border);
         if (border != otherBorder) {
-          NS_UpdateHint(aHint, border->CalcDifference(*otherBorder));
+          NS_UpdateHint(hint, border->CalcDifference(*otherBorder));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleList* list = (const nsStyleList*)PeekStyleData(eStyleStruct_List);
       if (list) {
         const nsStyleList* otherList = (const nsStyleList*)aOther->GetStyleData(eStyleStruct_List);
         if (list != otherList) {
-          NS_UpdateHint(aHint, list->CalcDifference(*otherList));
+          NS_UpdateHint(hint, list->CalcDifference(*otherList));
         }
       }
     }
     
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStylePosition* pos = (const nsStylePosition*)PeekStyleData(eStyleStruct_Position);
       if (pos) {
         const nsStylePosition* otherPosition = (const nsStylePosition*)aOther->GetStyleData(eStyleStruct_Position);
         if (pos != otherPosition) {
-          NS_UpdateHint(aHint, pos->CalcDifference(*otherPosition));
+          NS_UpdateHint(hint, pos->CalcDifference(*otherPosition));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleText* text = (const nsStyleText*)PeekStyleData(eStyleStruct_Text);
       if (text) {
         const nsStyleText* otherText = (const nsStyleText*)aOther->GetStyleData(eStyleStruct_Text);
         if (text != otherText) {
-          NS_UpdateHint(aHint, text->CalcDifference(*otherText));
+          NS_UpdateHint(hint, text->CalcDifference(*otherText));
         }
       }
     }
     
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleTextReset* text = (const nsStyleTextReset*)PeekStyleData(eStyleStruct_TextReset);
       if (text) {
         const nsStyleTextReset* otherText = (const nsStyleTextReset*)aOther->GetStyleData(eStyleStruct_TextReset);
         if (text != otherText) {
-          NS_UpdateHint(aHint, text->CalcDifference(*otherText));
+          NS_UpdateHint(hint, text->CalcDifference(*otherText));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleTable* table = (const nsStyleTable*)PeekStyleData(eStyleStruct_Table);
       if (table) {
         const nsStyleTable* otherTable = (const nsStyleTable*)aOther->GetStyleData(eStyleStruct_Table);
         if (table != otherTable) {
-          NS_UpdateHint(aHint, table->CalcDifference(*otherTable));
+          NS_UpdateHint(hint, table->CalcDifference(*otherTable));
         }
       }
     }
     
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleTableBorder* table = (const nsStyleTableBorder*)PeekStyleData(eStyleStruct_TableBorder);
       if (table) {
         const nsStyleTableBorder* otherTable = (const nsStyleTableBorder*)aOther->GetStyleData(eStyleStruct_TableBorder);
         if (table != otherTable) {
-          NS_UpdateHint(aHint, table->CalcDifference(*otherTable));
+          NS_UpdateHint(hint, table->CalcDifference(*otherTable));
         }
       }
     }
@@ -752,47 +643,47 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, nsChangeHint& aHint
 
     // The following structs cause (as their maximal difference) a re-render to occur.
     // VISUAL Structs: Color, Background, Outline, UIReset
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleColor* color = (const nsStyleColor*)PeekStyleData(eStyleStruct_Color);
       if (color) {
         const nsStyleColor* otherColor = (const nsStyleColor*)aOther->GetStyleData(eStyleStruct_Color);
         if (color != otherColor) {
-          NS_UpdateHint(aHint, color->CalcDifference(*otherColor));
+          NS_UpdateHint(hint, color->CalcDifference(*otherColor));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleBackground* background = (const nsStyleBackground*)PeekStyleData(eStyleStruct_Background);
       if (background) {
         const nsStyleBackground* otherBackground = (const nsStyleBackground*)aOther->GetStyleData(eStyleStruct_Background);
         if (background != otherBackground) {
-          NS_UpdateHint(aHint, background->CalcDifference(*otherBackground));
+          NS_UpdateHint(hint, background->CalcDifference(*otherBackground));
         }
       }
     }
     
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleOutline* outline = (const nsStyleOutline*)PeekStyleData(eStyleStruct_Outline);
       if (outline) {
         const nsStyleOutline* otherOutline = (const nsStyleOutline*)aOther->GetStyleData(eStyleStruct_Outline);
         if (outline != otherOutline) {
-          NS_UpdateHint(aHint, outline->CalcDifference(*otherOutline));
+          NS_UpdateHint(hint, outline->CalcDifference(*otherOutline));
         }
       }
     }
     
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleUIReset* ui = (const nsStyleUIReset*)PeekStyleData(eStyleStruct_UIReset);
       if (ui) {
         const nsStyleUIReset* otherUI = (const nsStyleUIReset*)aOther->GetStyleData(eStyleStruct_UIReset);
         if (ui != otherUI) {
-          NS_UpdateHint(aHint, ui->CalcDifference(*otherUI));
+          NS_UpdateHint(hint, ui->CalcDifference(*otherUI));
         }
       }
     }
   }
-  return NS_OK;
+  return hint;
 }
 
 #ifdef DEBUG
@@ -802,7 +693,7 @@ void nsStyleContext::List(FILE* out, PRInt32 aIndent)
   PRInt32 ix;
   for (ix = aIndent; --ix >= 0; ) fputs("  ", out);
   fprintf(out, "%p(%d) parent=%p ",
-          (void*)this, mRefCnt.get(), (void *)mParent);
+          (void*)this, mRefCnt, (void *)mParent);
   if (mPseudoTag) {
     nsAutoString  buffer;
     mPseudoTag->ToString(buffer);
@@ -1176,24 +1067,16 @@ nsStyleContext::Destroy()
   presContext->FreeToShell(sizeof(nsStyleContext), this);
 }
 
-NS_EXPORT nsresult
-NS_NewStyleContext(nsIStyleContext** aInstancePtrResult,
-                   nsIStyleContext* aParentContext,
+already_AddRefed<nsStyleContext>
+NS_NewStyleContext(nsStyleContext* aParentContext,
                    nsIAtom* aPseudoTag,
                    nsRuleNode* aRuleNode,
                    nsIPresContext* aPresContext)
 {
-  NS_PRECONDITION(nsnull != aInstancePtrResult, "null ptr");
-  if (nsnull == aInstancePtrResult) {
-    return NS_ERROR_NULL_POINTER;
-  }
-
   nsStyleContext* context = new (aPresContext) nsStyleContext(aParentContext, aPseudoTag, 
                                                               aRuleNode, aPresContext);
-  if (!context) {
-    return NS_ERROR_OUT_OF_MEMORY;
-  }
-
-  return CallQueryInterface(context, aInstancePtrResult);
+  if (context)
+    context->AddRef();
+  return context;
 }
 
diff --git a/mozilla/content/base/src/nsStyleSet.cpp b/mozilla/content/base/src/nsStyleSet.cpp
index cec07984b8f..9e4c35e439a 100644
--- a/mozilla/content/base/src/nsStyleSet.cpp
+++ b/mozilla/content/base/src/nsStyleSet.cpp
@@ -149,24 +149,27 @@ public:
 
   NS_IMETHOD NotifyStyleSheetStateChanged(PRBool aDisabled);
 
-  virtual nsIStyleContext* ResolveStyleFor(nsIPresContext* aPresContext,
-                                           nsIContent* aContent,
-                                           nsIStyleContext* aParentContext);
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleFor(nsIPresContext* aPresContext,
+                  nsIContent* aContent,
+                  nsStyleContext* aParentContext);
 
-  virtual nsIStyleContext* ResolveStyleForNonElement(
-                                           nsIPresContext* aPresContext,
-                                           nsIStyleContext* aParentContext);
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleForNonElement(nsIPresContext* aPresContext,
+                            nsStyleContext* aParentContext);
 
-  virtual nsIStyleContext* ResolvePseudoStyleFor(nsIPresContext* aPresContext,
-                                                 nsIContent* aParentContent,
-                                                 nsIAtom* aPseudoTag,
-                                                 nsIStyleContext* aParentContext,
-                                                 nsICSSPseudoComparator* aComparator = nsnull);
+  virtual already_AddRefed<nsStyleContext>
+  ResolvePseudoStyleFor(nsIPresContext* aPresContext,
+                        nsIContent* aParentContent,
+                        nsIAtom* aPseudoTag,
+                        nsStyleContext* aParentContext,
+                        nsICSSPseudoComparator* aComparator = nsnull);
 
-  virtual nsIStyleContext* ProbePseudoStyleFor(nsIPresContext* aPresContext,
-                                               nsIContent* aParentContent,
-                                               nsIAtom* aPseudoTag,
-                                               nsIStyleContext* aParentContext);
+  virtual already_AddRefed<nsStyleContext>
+  ProbePseudoStyleFor(nsIPresContext* aPresContext,
+                      nsIContent* aParentContent,
+                      nsIAtom* aPseudoTag,
+                      nsStyleContext* aParentContext);
 
   NS_IMETHOD Shutdown();
 
@@ -189,7 +192,7 @@ public:
   
   virtual nsresult AddRuleNodeMapping(nsRuleNode* aRuleNode);
 
-  virtual nsresult ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule, nsIStyleContext* aContext);
+  virtual nsresult ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule, nsStyleContext* aContext);
 
   virtual nsresult GetStyleFrameConstruction(nsIStyleFrameConstruction** aResult) {
     *aResult = mFrameConstructor;
@@ -197,10 +200,10 @@ public:
     return NS_OK;
   }
 
-  NS_IMETHOD ReParentStyleContext(nsIPresContext* aPresContext,
-                                  nsIStyleContext* aStyleContext, 
-                                  nsIStyleContext* aNewParentContext,
-                                  nsIStyleContext** aNewStyleContext);
+  virtual already_AddRefed<nsStyleContext>
+  ReParentStyleContext(nsIPresContext* aPresContext,
+                       nsStyleContext* aStyleContext, 
+                       nsStyleContext* aNewParentContext);
 
   NS_IMETHOD HasStateDependentStyle(nsIPresContext* aPresContext,
                                     nsIContent*     aContent,
@@ -335,9 +338,9 @@ protected:
   void WalkRuleProcessors(nsISupportsArrayEnumFunc aFunc,
                           RuleProcessorData* aData);
 
-  nsIStyleContext* GetContext(nsIPresContext* aPresContext, 
-                              nsIStyleContext* aParentContext,
-                              nsIAtom* aPseudoTag);
+  already_AddRefed<nsStyleContext> GetContext(nsIPresContext* aPresContext, 
+                                              nsStyleContext* aParentContext,
+                                              nsIAtom* aPseudoTag);
 
 #ifdef DEBUG
   void  List(FILE* out, PRInt32 aIndent, nsISupportsArray* aSheets);
@@ -999,15 +1002,16 @@ EnumRulesMatching(nsISupports* aProcessor, void* aData)
  * generation.  (It works for cousins of the same generation since
  * |aParentContext| could itself be a shared context.)
  */
-nsIStyleContext* StyleSetImpl::GetContext(nsIPresContext* aPresContext, 
-                                          nsIStyleContext* aParentContext, 
-                                          nsIAtom* aPseudoTag)
+already_AddRefed<nsStyleContext>
+StyleSetImpl::GetContext(nsIPresContext* aPresContext, 
+                         nsStyleContext* aParentContext, 
+                         nsIAtom* aPseudoTag)
 {
-  nsIStyleContext* result = nsnull;
+  nsStyleContext* result = nsnull;
   nsRuleNode* ruleNode = mRuleWalker->GetCurrentNode();
       
   if (aParentContext)
-    aParentContext->FindChildWithRules(aPseudoTag, ruleNode, result);
+    result = aParentContext->FindChildWithRules(aPseudoTag, ruleNode).get();
 
 #ifdef NOISY_DEBUG
   if (result)
@@ -1017,8 +1021,8 @@ nsIStyleContext* StyleSetImpl::GetContext(nsIPresContext* aPresContext,
 #endif
 
   if (!result)
-    NS_NewStyleContext(&result, aParentContext, aPseudoTag, ruleNode,
-                       aPresContext);
+    result = NS_NewStyleContext(aParentContext, aPseudoTag, ruleNode,
+                                aPresContext).get();
 
   return result;
 }
@@ -1150,14 +1154,15 @@ void StyleSetImpl::EnsureRuleWalker(nsIPresContext* aPresContext)
   mRuleWalker = new nsRuleWalker(mRuleTree);
 }
 
-nsIStyleContext* StyleSetImpl::ResolveStyleFor(nsIPresContext* aPresContext,
-                                               nsIContent* aContent,
-                                               nsIStyleContext* aParentContext)
+already_AddRefed<nsStyleContext>
+StyleSetImpl::ResolveStyleFor(nsIPresContext* aPresContext,
+                              nsIContent* aContent,
+                              nsStyleContext* aParentContext)
 {
   MOZ_TIMER_DEBUGLOG(("Start: StyleSetImpl::ResolveStyleFor(), this=%p\n", this));
   STYLESET_START_TIMER(NS_TIMER_STYLE_RESOLUTION);
 
-  nsIStyleContext*  result = nsnull;
+  nsStyleContext*  result = nsnull;
 
   NS_ASSERTION(aContent, "must have content");
   NS_ASSERTION(aPresContext, "must have pres context");
@@ -1175,7 +1180,7 @@ nsIStyleContext* StyleSetImpl::ResolveStyleFor(nsIPresContext* aPresContext,
       aPresContext->GetMedium(getter_AddRefs(medium));
       RulesMatchingData data(aPresContext, medium, aContent, mRuleWalker);
       FileRules(EnumRulesMatching, &data);
-      result = GetContext(aPresContext, aParentContext, nsnull);
+      result = GetContext(aPresContext, aParentContext, nsnull).get();
      
       // Now reset the walker back to the root of the tree.
       mRuleWalker->Reset();
@@ -1187,14 +1192,14 @@ nsIStyleContext* StyleSetImpl::ResolveStyleFor(nsIPresContext* aPresContext,
   return result;
 }
 
-nsIStyleContext* StyleSetImpl::ResolveStyleForNonElement(
-                                               nsIPresContext* aPresContext,
-                                               nsIStyleContext* aParentContext)
+already_AddRefed<nsStyleContext>
+StyleSetImpl::ResolveStyleForNonElement(nsIPresContext* aPresContext,
+                                        nsStyleContext* aParentContext)
 {
   MOZ_TIMER_DEBUGLOG(("Start: StyleSetImpl::ResolveStyleForNonElement(), this=%p\n", this));
   STYLESET_START_TIMER(NS_TIMER_STYLE_RESOLUTION);
 
-  nsIStyleContext* result = nsnull;
+  nsStyleContext* result = nsnull;
 
   NS_ASSERTION(aPresContext, "must have pres context");
 
@@ -1206,7 +1211,7 @@ nsIStyleContext* StyleSetImpl::ResolveStyleForNonElement(
         mOverrideRuleProcessors) {
       EnsureRuleWalker(aPresContext);
       result = GetContext(aPresContext, aParentContext,
-                          nsCSSAnonBoxes::mozNonElement);
+                          nsCSSAnonBoxes::mozNonElement).get();
       NS_ASSERTION(mRuleWalker->AtRoot(), "rule walker must be at root");
     }
   }
@@ -1242,16 +1247,17 @@ EnumPseudoRulesMatching(nsISupports* aProcessor, void* aData)
   return PR_TRUE;
 }
 
-nsIStyleContext* StyleSetImpl::ResolvePseudoStyleFor(nsIPresContext* aPresContext,
-                                                     nsIContent* aParentContent,
-                                                     nsIAtom* aPseudoTag,
-                                                     nsIStyleContext* aParentContext,
-                                                     nsICSSPseudoComparator* aComparator)
+already_AddRefed<nsStyleContext>
+StyleSetImpl::ResolvePseudoStyleFor(nsIPresContext* aPresContext,
+                                    nsIContent* aParentContent,
+                                    nsIAtom* aPseudoTag,
+                                    nsStyleContext* aParentContext,
+                                    nsICSSPseudoComparator* aComparator)
 {
   MOZ_TIMER_DEBUGLOG(("Start: StyleSetImpl::ResolvePseudoStyleFor(), this=%p\n", this));
   STYLESET_START_TIMER(NS_TIMER_STYLE_RESOLUTION);
 
-  nsIStyleContext*  result = nsnull;
+  nsStyleContext*  result = nsnull;
 
   NS_ASSERTION(aPseudoTag, "must have pseudo tag");
   NS_ASSERTION(aPresContext, "must have pres context");
@@ -1272,7 +1278,7 @@ nsIStyleContext* StyleSetImpl::ResolvePseudoStyleFor(nsIPresContext* aPresContex
                                    aPseudoTag, aComparator, mRuleWalker);
       FileRules(EnumPseudoRulesMatching, &data);
 
-      result = GetContext(aPresContext, aParentContext, aPseudoTag);
+      result = GetContext(aPresContext, aParentContext, aPseudoTag).get();
      
       // Now reset the walker back to the root of the tree.
       mRuleWalker->Reset();
@@ -1284,15 +1290,16 @@ nsIStyleContext* StyleSetImpl::ResolvePseudoStyleFor(nsIPresContext* aPresContex
   return result;
 }
 
-nsIStyleContext* StyleSetImpl::ProbePseudoStyleFor(nsIPresContext* aPresContext,
-                                                   nsIContent* aParentContent,
-                                                   nsIAtom* aPseudoTag,
-                                                   nsIStyleContext* aParentContext)
+already_AddRefed<nsStyleContext>
+StyleSetImpl::ProbePseudoStyleFor(nsIPresContext* aPresContext,
+                                  nsIContent* aParentContent,
+                                  nsIAtom* aPseudoTag,
+                                  nsStyleContext* aParentContext)
 {
   MOZ_TIMER_DEBUGLOG(("Start: StyleSetImpl::ProbePseudoStyleFor(), this=%p\n", this));
   STYLESET_START_TIMER(NS_TIMER_STYLE_RESOLUTION);
 
-  nsIStyleContext*  result = nsnull;
+  nsStyleContext*  result = nsnull;
 
   NS_ASSERTION(aPseudoTag, "must have pseudo tag");
   NS_ASSERTION(aPresContext, "must have pres context");
@@ -1314,7 +1321,7 @@ nsIStyleContext* StyleSetImpl::ProbePseudoStyleFor(nsIPresContext* aPresContext,
       FileRules(EnumPseudoRulesMatching, &data);
 
       if (!mRuleWalker->AtRoot())
-        result = GetContext(aPresContext, aParentContext, aPseudoTag);
+        result = GetContext(aPresContext, aParentContext, aPseudoTag).get();
  
       // Now reset the walker back to the root of the tree.
       mRuleWalker->Reset();
@@ -1397,7 +1404,7 @@ StyleSetImpl::ClearCachedDataInRuleTree(nsIStyleRule* aInlineStyleRule)
 }
 
 nsresult
-StyleSetImpl::ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule, nsIStyleContext* aContext)
+StyleSetImpl::ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule, nsStyleContext* aContext)
 {
   // XXXdwh.  If we're willing to *really* optimize this
   // invalidation, we could only invalidate the struct data
@@ -1450,8 +1457,7 @@ StyleSetImpl::ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule,
     nsIFrame* rootFrame;
     shell->GetRootFrame(&rootFrame);
     if (rootFrame) {
-      nsCOMPtr<nsIStyleContext> rootContext;
-      rootFrame->GetStyleContext(getter_AddRefs(rootContext));
+      nsStyleContext* rootContext = rootFrame->GetStyleContext();
       if (rootContext)
         rootContext->ClearStyleData(aPresContext, aRule);
     }
@@ -1460,46 +1466,38 @@ StyleSetImpl::ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule,
   return NS_OK;
 }
 
-NS_IMETHODIMP
+already_AddRefed<nsStyleContext>
 StyleSetImpl::ReParentStyleContext(nsIPresContext* aPresContext,
-                                   nsIStyleContext* aStyleContext, 
-                                   nsIStyleContext* aNewParentContext,
-                                   nsIStyleContext** aNewStyleContext)
+                                   nsStyleContext* aStyleContext, 
+                                   nsStyleContext* aNewParentContext)
 {
   NS_ASSERTION(aPresContext, "must have pres context");
   NS_ASSERTION(aStyleContext, "must have style context");
-  NS_ASSERTION(aNewStyleContext, "must have new style context");
 
-  nsresult result = NS_ERROR_NULL_POINTER;
-
-  if (aPresContext && aStyleContext && aNewStyleContext) {
-    nsCOMPtr<nsIStyleContext> oldParent = aStyleContext->GetParent();
+  if (aPresContext && aStyleContext) {
+    nsStyleContext* oldParent = aStyleContext->GetParent();
 
     if (oldParent == aNewParentContext) {
-      result = NS_OK;
-      NS_ADDREF(aStyleContext);   // for return
-      *aNewStyleContext = aStyleContext;
+      aStyleContext->AddRef();
+      return aStyleContext;
     }
     else {  // really a new parent
-      nsIStyleContext*  newChild = nsnull;
-      nsCOMPtr<nsIAtom>  pseudoTag;
-      aStyleContext->GetPseudoType(*getter_AddRefs(pseudoTag));
+      nsStyleContext*  newChild = nsnull;
+      nsCOMPtr<nsIAtom>  pseudoTag = aStyleContext->GetPseudoType();
 
       nsRuleNode* ruleNode;
       aStyleContext->GetRuleNode(&ruleNode);
-      if (aNewParentContext) {
-        result = aNewParentContext->FindChildWithRules(pseudoTag, ruleNode, newChild);
-      }
-      if (newChild) { // new parent already has one
-        *aNewStyleContext = newChild;
-      }
+      if (aNewParentContext)
+        newChild = aNewParentContext->FindChildWithRules(pseudoTag, ruleNode).get();
+      if (newChild) // new parent already has one
+        return newChild;
       else {  // need to make one in the new parent
-        result = NS_NewStyleContext(aNewStyleContext, aNewParentContext, pseudoTag,
-                                    ruleNode, aPresContext);
+        return NS_NewStyleContext(aNewParentContext, pseudoTag, ruleNode,
+                                  aPresContext);
       }
     }
   }
-  return result;
+  return nsnull;
 }
 
 struct StatefulData : public StateRuleProcessorData {
@@ -1764,8 +1762,7 @@ void StyleSetImpl::List(FILE* out, PRInt32 aIndent)
 
 void StyleSetImpl::ListContexts(nsIFrame* aRootFrame, FILE* out, PRInt32 aIndent)
 {
-  nsCOMPtr<nsIStyleContext> sc;
-  aRootFrame->GetStyleContext(getter_AddRefs(sc));
+  nsStyleContext* sc = aRootFrame->GetStyleContext();
   if (sc)
     sc->List(out, aIndent);
 }
diff --git a/mozilla/content/html/content/src/nsHTMLSharedElement.cpp b/mozilla/content/html/content/src/nsHTMLSharedElement.cpp
index dcd6e39f9a0..6b0d0f4b27b 100644
--- a/mozilla/content/html/content/src/nsHTMLSharedElement.cpp
+++ b/mozilla/content/html/content/src/nsHTMLSharedElement.cpp
@@ -47,6 +47,7 @@
 #include "nsIPresContext.h"
 #include "nsRuleNode.h"
 #include "nsHTMLAttributes.h"
+#include "nsStyleContext.h"
 
 
 class nsHTMLSharedLeafElement : public nsGenericHTMLLeafElement,
diff --git a/mozilla/content/html/content/src/nsHTMLSharedLeafElement.cpp b/mozilla/content/html/content/src/nsHTMLSharedLeafElement.cpp
index dcd6e39f9a0..6b0d0f4b27b 100644
--- a/mozilla/content/html/content/src/nsHTMLSharedLeafElement.cpp
+++ b/mozilla/content/html/content/src/nsHTMLSharedLeafElement.cpp
@@ -47,6 +47,7 @@
 #include "nsIPresContext.h"
 #include "nsRuleNode.h"
 #include "nsHTMLAttributes.h"
+#include "nsStyleContext.h"
 
 
 class nsHTMLSharedLeafElement : public nsGenericHTMLLeafElement,
diff --git a/mozilla/content/html/content/src/nsHTMLTableElement.cpp b/mozilla/content/html/content/src/nsHTMLTableElement.cpp
index 1a76de9fa0a..bf5b59c7974 100644
--- a/mozilla/content/html/content/src/nsHTMLTableElement.cpp
+++ b/mozilla/content/html/content/src/nsHTMLTableElement.cpp
@@ -50,6 +50,7 @@
 #include "nsIPresContext.h"
 #include "nsHTMLParts.h"
 #include "nsRuleNode.h"
+#include "nsStyleContext.h"
 
 /* for collections */
 #include "nsIDOMElement.h"
diff --git a/mozilla/content/html/document/src/nsImageDocument.cpp b/mozilla/content/html/document/src/nsImageDocument.cpp
index 094f93c1219..694f5a85ac8 100644
--- a/mozilla/content/html/document/src/nsImageDocument.cpp
+++ b/mozilla/content/html/document/src/nsImageDocument.cpp
@@ -55,11 +55,12 @@
 #include "nsIScrollable.h"
 #include "nsIPresShell.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIViewManager.h"
 #include "nsIStringBundle.h"
 #include "nsIPrefService.h"
 #include "nsITextToSubURI.h"
+#include "nsAutoPtr.h"
 
 #define NSIMAGEDOCUMENT_PROPERTIES_URI "chrome://communicator/locale/layout/ImageDocument.properties"
 #define AUTOMATIC_IMAGE_RESIZING_PREF "browser.enable_automatic_image_resizing"
@@ -594,9 +595,8 @@ nsImageDocument::CheckOverflowing()
   nsRect visibleArea;
   context->GetVisibleArea(visibleArea);
 
-  nsCOMPtr<nsIStyleContext> styleContext;
   nsCOMPtr<nsIContent> content = do_QueryInterface(mBodyContent);
-  context->ResolveStyleContextFor(content, nsnull, getter_AddRefs(styleContext));
+  nsRefPtr<nsStyleContext> styleContext = context->ResolveStyleContextFor(content, nsnull);
 
   const nsStyleMargin* marginData =
     (const nsStyleMargin*)styleContext->GetStyleData(eStyleStruct_Margin);
diff --git a/mozilla/content/html/style/public/nsStyleUtil.h b/mozilla/content/html/style/public/nsStyleUtil.h
index 5a33ee77bdd..6393e157d98 100644
--- a/mozilla/content/html/style/public/nsStyleUtil.h
+++ b/mozilla/content/html/style/public/nsStyleUtil.h
@@ -42,7 +42,6 @@
 #include "nsIPresContext.h"
 #include "nsILinkHandler.h" // for nsLinkState
 
-class nsIStyleContext;
 struct nsStyleBackground;
 
 enum nsFontSizeType {
diff --git a/mozilla/content/html/style/src/nsCSSStyleRule.cpp b/mozilla/content/html/style/src/nsCSSStyleRule.cpp
index 88d21e667f1..3795eb52a37 100644
--- a/mozilla/content/html/style/src/nsCSSStyleRule.cpp
+++ b/mozilla/content/html/style/src/nsCSSStyleRule.cpp
@@ -73,6 +73,7 @@
 #include "nsISizeOfHandler.h"
 
 #include "nsContentUtils.h"
+#include "nsContentErrors.h"
 
 // #define DEBUG_REFS
  
diff --git a/mozilla/content/html/style/src/nsComputedDOMStyle.cpp b/mozilla/content/html/style/src/nsComputedDOMStyle.cpp
index 9c5cf771a27..685367036d5 100644
--- a/mozilla/content/html/style/src/nsComputedDOMStyle.cpp
+++ b/mozilla/content/html/style/src/nsComputedDOMStyle.cpp
@@ -44,7 +44,7 @@
 #include "nsDOMError.h"
 #include "nsIDOMCSS2Properties.h"
 #include "nsIDOMElement.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIScrollableFrame.h"
 #include "nsContentUtils.h"
 #include "prprf.h"
@@ -3034,18 +3034,16 @@ nsComputedDOMStyle::GetStyleData(nsStyleStructID aID,
     nsCOMPtr<nsIPresContext> pctx;
     presShell->GetPresContext(getter_AddRefs(pctx));
     if (pctx) {
-      nsCOMPtr<nsIStyleContext> sctx;
+      nsStyleContext* sctx;
       if (!mPseudo) {
-        pctx->ResolveStyleContextFor(mContent, nsnull,
-                                     getter_AddRefs(sctx));
+        sctx = pctx->ResolveStyleContextFor(mContent, nsnull).get();
       } else {
-        pctx->ResolvePseudoStyleContextFor(mContent, mPseudo, nsnull,
-                                           getter_AddRefs(sctx));
+        sctx = pctx->ResolvePseudoStyleContextFor(mContent, mPseudo, nsnull).get();
       }
       if (sctx) {
         aStyleStruct = sctx->GetStyleData(aID);
       }
-      mStyleContextHolder = sctx;
+      mStyleContextHolder = dont_AddRef(sctx);  // transfer ref from sctx
     }
   }
   NS_ASSERTION(aStyleStruct, "Failed to get a style struct");
diff --git a/mozilla/content/html/style/src/nsComputedDOMStyle.h b/mozilla/content/html/style/src/nsComputedDOMStyle.h
index cdcd52b9dd3..e51d29ee2f4 100644
--- a/mozilla/content/html/style/src/nsComputedDOMStyle.h
+++ b/mozilla/content/html/style/src/nsComputedDOMStyle.h
@@ -53,6 +53,7 @@
 #include "nsIFrame.h"
 #include "nsCOMPtr.h"
 #include "nsWeakReference.h"
+#include "nsAutoPtr.h"
 
 class nsComputedDOMStyle : public nsIComputedDOMStyle
 {
@@ -302,7 +303,7 @@ private:
    * When a frame is unavailable, strong reference to the
    * style context while we're accessing the data from in.
    */
-  nsCOMPtr<nsIStyleContext> mStyleContextHolder;
+  nsRefPtr<nsStyleContext> mStyleContextHolder;
   nsCOMPtr<nsIAtom> mPseudo;
 
   float mT2P; /* For unit conversions */
diff --git a/mozilla/content/html/style/src/nsHTMLStyleSheet.cpp b/mozilla/content/html/style/src/nsHTMLStyleSheet.cpp
index 9400f2caa72..bd1ff22e153 100644
--- a/mozilla/content/html/style/src/nsHTMLStyleSheet.cpp
+++ b/mozilla/content/html/style/src/nsHTMLStyleSheet.cpp
@@ -42,7 +42,7 @@
 #include "nsIStyleRuleProcessor.h"
 #include "nsIStyleRule.h"
 #include "nsIFrame.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsHTMLAtoms.h"
 #include "nsIPresContext.h"
 #include "nsIEventStateManager.h"
@@ -393,7 +393,7 @@ static void PostResolveCallback(nsStyleStruct* aStyleStruct, nsRuleData* aRuleDa
 {
   nsStyleText* text = (nsStyleText*)aStyleStruct;
   if (text->mTextAlign == NS_STYLE_TEXT_ALIGN_DEFAULT) {
-    nsCOMPtr<nsIStyleContext> parentContext = aRuleData->mStyleContext->GetParent();
+    nsStyleContext* parentContext = aRuleData->mStyleContext->GetParent();
 
     if (parentContext) {
       const nsStyleText* parentStyleText = 
@@ -426,7 +426,7 @@ ProcessTableRulesAttribute(nsStyleStruct* aStyleStruct,
 {
   if (!aStyleStruct || !aRuleData || !aRuleData->mPresContext) return;
 
-  nsCOMPtr<nsIStyleContext> tableContext = aRuleData->mStyleContext->GetParent();
+  nsStyleContext* tableContext = aRuleData->mStyleContext->GetParent();
   if (!tableContext)
     return;
   if (!aGroup) {
diff --git a/mozilla/content/html/style/src/nsInspectorCSSUtils.cpp b/mozilla/content/html/style/src/nsInspectorCSSUtils.cpp
index 9d073a32cd3..b327a0ab4b5 100644
--- a/mozilla/content/html/style/src/nsInspectorCSSUtils.cpp
+++ b/mozilla/content/html/style/src/nsInspectorCSSUtils.cpp
@@ -43,6 +43,8 @@
 #include "nsLayoutAtoms.h"
 #include "nsIDocument.h"
 #include "nsIPresShell.h"
+#include "nsAutoPtr.h"
+#include "nsIFrame.h"
 
 nsInspectorCSSUtils::nsInspectorCSSUtils()
 {
@@ -113,18 +115,12 @@ nsInspectorCSSUtils::AdjustRectForMargins(nsIFrame* aFrame, nsRect& aRect)
   return NS_OK;
 }
 
-nsresult
-nsInspectorCSSUtils::GetStyleContextForFrame(nsIFrame* aFrame,
-                                             nsIStyleContext** aStyleContext)
+nsStyleContext*
+nsInspectorCSSUtils::GetStyleContextForFrame(nsIFrame* aFrame)
 {
-    nsCOMPtr<nsIStyleContext> styleContext;
-    aFrame->GetStyleContext(getter_AddRefs(styleContext));
-    if (!styleContext) {
-        // Caller returns rv on through, and this does not seem
-        // exception-worthy.
-        *aStyleContext = nsnull;
-        return NS_OK;
-    }
+    nsStyleContext* styleContext = aFrame->GetStyleContext();
+    if (!styleContext)
+        return nsnull;
 
     /* For tables the primary frame is the "outer frame" but the style
      * rules are applied to the "inner frame".  Luckily, the "outer
@@ -133,45 +129,42 @@ nsInspectorCSSUtils::GetStyleContextForFrame(nsIFrame* aFrame,
      */
     nsCOMPtr<nsIAtom> frameType;
     aFrame->GetFrameType(getter_AddRefs(frameType));
-    if (frameType == nsLayoutAtoms::tableOuterFrame) {
-        *aStyleContext = styleContext->GetParent().get();
-    } else {
-        *aStyleContext = styleContext;
-        NS_ADDREF(*aStyleContext);
-    }
-    return NS_OK;
+    if (frameType == nsLayoutAtoms::tableOuterFrame)
+        return styleContext->GetParent();
+
+    return styleContext;
 }    
 
-nsresult
+already_AddRefed<nsStyleContext>
 nsInspectorCSSUtils::GetStyleContextForContent(nsIContent* aContent,
-                                               nsIPresShell* aPresShell,
-                                               nsIStyleContext** aStyleContext)
+                                               nsIPresShell* aPresShell)
 {
     nsIFrame* frame = nsnull;
     aPresShell->GetPrimaryFrameFor(aContent, &frame);
-    if (frame)
-        return GetStyleContextForFrame(frame, aStyleContext);
+    if (frame) {
+        nsStyleContext* result = GetStyleContextForFrame(frame);
+        // this function returns an addrefed style context
+        if (result)
+            result->AddRef();
+        return result;
+    }
 
     // No frame has been created, so resolve the style ourselves
-    nsCOMPtr<nsIStyleContext> parentContext;
+    nsRefPtr<nsStyleContext> parentContext;
     nsCOMPtr<nsIContent> parent;
     aContent->GetParent(*getter_AddRefs(parent));
-    if (parent) {
-        nsresult rv = GetStyleContextForContent(parent, aPresShell,
-                                                getter_AddRefs(parentContext));
-        NS_ENSURE_SUCCESS(rv, rv);
-    }
+    if (parent)
+        parentContext = GetStyleContextForContent(parent, aPresShell);
 
     nsCOMPtr<nsIPresContext> presContext;
     aPresShell->GetPresContext(getter_AddRefs(presContext));
-    NS_ENSURE_TRUE(presContext, NS_ERROR_UNEXPECTED);
+    if (!presContext)
+        return nsnull;
 
     if (aContent->IsContentOfType(nsIContent::eELEMENT))
-        return presContext->ResolveStyleContextFor(aContent, parentContext,
-                                                   aStyleContext);
+        return presContext->ResolveStyleContextFor(aContent, parentContext);
 
-    return presContext->ResolveStyleContextForNonElement(parentContext,
-                                                         aStyleContext);
+    return presContext->ResolveStyleContextForNonElement(parentContext);
 }
 
 NS_IMETHODIMP
@@ -188,10 +181,7 @@ nsInspectorCSSUtils::GetRuleNodeForContent(nsIContent* aContent,
     doc->GetShellAt(0, getter_AddRefs(presShell));
     NS_ENSURE_TRUE(presShell, NS_ERROR_UNEXPECTED);
 
-    nsCOMPtr<nsIStyleContext> sContext;
-    nsresult rv = GetStyleContextForContent(aContent, presShell,
-                                            getter_AddRefs(sContext));
-    NS_ENSURE_SUCCESS(rv, rv);
-
-    return sContext->GetRuleNode(aRuleNode);
+    nsRefPtr<nsStyleContext> sContext = GetStyleContextForContent(aContent, presShell);
+    sContext->GetRuleNode(aRuleNode);
+    return NS_OK;
 }
diff --git a/mozilla/content/html/style/src/nsInspectorCSSUtils.h b/mozilla/content/html/style/src/nsInspectorCSSUtils.h
index eef6a8176a3..65158b2b7a3 100644
--- a/mozilla/content/html/style/src/nsInspectorCSSUtils.h
+++ b/mozilla/content/html/style/src/nsInspectorCSSUtils.h
@@ -41,9 +41,10 @@
 #define nsInspectorCSSUtils_h___
 
 #include "nsIInspectorCSSUtils.h"
+#include "nsStyleContext.h"
+#include "nsAutoPtr.h"
 
 class nsIPresShell;
-class nsIStyleContext;
 
 class nsInspectorCSSUtils : public nsIInspectorCSSUtils {
 
@@ -64,11 +65,10 @@ public:
                                      nsRuleNode** aRuleNode);
 
 private:
-    nsresult GetStyleContextForContent(nsIContent* aContent,
-                                       nsIPresShell* aPresShell,
-                                       nsIStyleContext** aStyleContext);
-    nsresult GetStyleContextForFrame(nsIFrame* aFrame,
-                                     nsIStyleContext** aStyleContext);
+    already_AddRefed<nsStyleContext>
+    GetStyleContextForContent(nsIContent* aContent, nsIPresShell* aPresShell);
+
+    nsStyleContext* GetStyleContextForFrame(nsIFrame* aFrame);
 };
 
 #endif /* nsInspectorCSSUtils_h___ */
diff --git a/mozilla/content/shared/public/Makefile.in b/mozilla/content/shared/public/Makefile.in
index c9c8dc45f23..8f1924fd5ea 100644
--- a/mozilla/content/shared/public/Makefile.in
+++ b/mozilla/content/shared/public/Makefile.in
@@ -50,6 +50,7 @@ nsLayoutAtomList.h \
 nsLayoutAtoms.h \
 nsRuleNode.h \
 nsRuleWalker.h \
+nsStyleContext.h \
 nsStyleCoord.h \
 nsStyleStruct.h \
 nsStyleStructList.h \
diff --git a/mozilla/content/shared/public/nsRuleNode.h b/mozilla/content/shared/public/nsRuleNode.h
index 746e6dd01df..fe978d1ab8c 100644
--- a/mozilla/content/shared/public/nsRuleNode.h
+++ b/mozilla/content/shared/public/nsRuleNode.h
@@ -42,13 +42,13 @@
 
 #include "nsCOMPtr.h"
 #include "nsIStyleRule.h"
-#include "nsIFrame.h"
 #include "nsFixedSizeAllocator.h"
 #include "nsIPresContext.h"
 #include "nsCSSDeclaration.h"
 #include "nsILanguageAtomService.h"
+#include "nsStyleStruct.h"
 
-class nsIStyleContext;
+class nsStyleContext;
 struct nsRuleList;
 struct PLDHashTable;
 
@@ -245,7 +245,7 @@ struct nsRuleData
   nsStyleStructID mSID;
   PRPackedBool mCanStoreInRuleTree;
   nsIPresContext* mPresContext;
-  nsIStyleContext* mStyleContext;
+  nsStyleContext* mStyleContext;
   nsPostResolveFunc mPostResolveCallback;
   nsRuleDataFont* mFontData; // Should always be stack-allocated! We don't own these structures!
   nsRuleDataDisplay* mDisplayData;
@@ -266,7 +266,7 @@ struct nsRuleData
   nsRuleDataSVG* mSVGData;
 #endif
 
-  nsRuleData(const nsStyleStructID& aSID, nsIPresContext* aContext, nsIStyleContext* aStyleContext) 
+  nsRuleData(const nsStyleStructID& aSID, nsIPresContext* aContext, nsStyleContext* aStyleContext) 
     :mSID(aSID), mPresContext(aContext), mStyleContext(aStyleContext), mPostResolveCallback(nsnull),
      mFontData(nsnull), mDisplayData(nsnull), mMarginData(nsnull), mListData(nsnull), 
      mPositionData(nsnull), mTableData(nsnull), mColorData(nsnull), mContentData(nsnull), mTextData(nsnull),
@@ -409,89 +409,89 @@ protected:
   void PropagateDependentBit(PRUint32 aBit, nsRuleNode* aHighestNode);
   void PropagateNoneBit(PRUint32 aBit, nsRuleNode* aHighestNode);
   
-  const nsStyleStruct* SetDefaultOnRoot(const nsStyleStructID aSID, nsIStyleContext* aContext);
+  const nsStyleStruct* SetDefaultOnRoot(const nsStyleStructID aSID, nsStyleContext* aContext);
 
-  const nsStyleStruct* WalkRuleTree(const nsStyleStructID aSID, nsIStyleContext* aContext, 
+  const nsStyleStruct* WalkRuleTree(const nsStyleStructID aSID, nsStyleContext* aContext, 
                                     nsRuleData* aRuleData,
                                     nsRuleDataStruct* aSpecificData,
                                     PRBool aComputeData);
 
   const nsStyleStruct* ComputeDisplayData(nsStyleStruct* aStartDisplay, const nsRuleDataStruct& aDisplayData, 
-                                          nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                          nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                           const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeVisibilityData(nsStyleStruct* aStartVisibility, const nsRuleDataStruct& aDisplayData, 
-                                             nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                             nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                              const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeFontData(nsStyleStruct* aStartFont, const nsRuleDataStruct& aFontData, 
-                                       nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                       nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                        const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeColorData(nsStyleStruct* aStartColor, const nsRuleDataStruct& aColorData, 
-                                        nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                        nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                         const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeBackgroundData(nsStyleStruct* aStartBackground, const nsRuleDataStruct& aColorData, 
-                                             nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                             nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                              const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeMarginData(nsStyleStruct* aStartMargin, const nsRuleDataStruct& aMarginData, 
-                                         nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                         nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                          const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeBorderData(nsStyleStruct* aStartBorder, const nsRuleDataStruct& aMarginData, 
-                                         nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                         nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                          const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputePaddingData(nsStyleStruct* aStartPadding, const nsRuleDataStruct& aMarginData, 
-                                          nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                          nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                           const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeOutlineData(nsStyleStruct* aStartOutline, const nsRuleDataStruct& aMarginData, 
-                                          nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                          nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                           const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeListData(nsStyleStruct* aStartList, const nsRuleDataStruct& aListData, 
-                                       nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                       nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                        const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputePositionData(nsStyleStruct* aStartPosition, const nsRuleDataStruct& aPositionData, 
-                                           nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                           nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                            const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeTableData(nsStyleStruct* aStartTable, const nsRuleDataStruct& aTableData, 
-                                        nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                        nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                         const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeTableBorderData(nsStyleStruct* aStartTable, const nsRuleDataStruct& aTableData, 
-                                              nsIStyleContext* aContext,  
+                                              nsStyleContext* aContext,  
                                               nsRuleNode* aHighestNode,
                                               const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeContentData(nsStyleStruct* aStartContent, const nsRuleDataStruct& aData, 
-                                          nsIStyleContext* aContext,  
+                                          nsStyleContext* aContext,  
                                           nsRuleNode* aHighestNode,
                                           const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeQuotesData(nsStyleStruct* aStartQuotes, const nsRuleDataStruct& aData, 
-                                         nsIStyleContext* aContext,  
+                                         nsStyleContext* aContext,  
                                          nsRuleNode* aHighestNode,
                                          const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeTextData(nsStyleStruct* aStartData, const nsRuleDataStruct& aData, 
-                                       nsIStyleContext* aContext,  
+                                       nsStyleContext* aContext,  
                                        nsRuleNode* aHighestNode,
                                        const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeTextResetData(nsStyleStruct* aStartData, const nsRuleDataStruct& aData, 
-                                            nsIStyleContext* aContext,  
+                                            nsStyleContext* aContext,  
                                             nsRuleNode* aHighestNode,
                                             const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeUserInterfaceData(nsStyleStruct* aStartData,
                                                 const nsRuleDataStruct& aData, 
-                                                nsIStyleContext* aContext,  
+                                                nsStyleContext* aContext,  
                                                 nsRuleNode* aHighestNode,
                                                 const RuleDetail& aRuleDetail,
                                                 PRBool aInherited);
   const nsStyleStruct* ComputeUIResetData(nsStyleStruct* aStartData, const nsRuleDataStruct& aData, 
-                                          nsIStyleContext* aContext,  
+                                          nsStyleContext* aContext,  
                                           nsRuleNode* aHighestNode,
                                           const RuleDetail& aRuleDetail, PRBool aInherited);
 #ifdef INCLUDE_XUL
   const nsStyleStruct* ComputeXULData(nsStyleStruct* aStartXUL, const nsRuleDataStruct& aXULData, 
-                                      nsIStyleContext* aContext,  
+                                      nsStyleContext* aContext,  
                                       nsRuleNode* aHighestNode,
                                       const RuleDetail& aRuleDetail, PRBool aInherited);
 #endif
 
 #ifdef MOZ_SVG
   const nsStyleStruct* ComputeSVGData(nsStyleStruct* aStartSVG, const nsRuleDataStruct& aSVGData, 
-                                      nsIStyleContext* aContext,  
+                                      nsStyleContext* aContext,  
                                       nsRuleNode* aHighestNode,
                                       const RuleDetail& aRuleDetail, PRBool aInherited);
 #endif
@@ -499,7 +499,7 @@ protected:
   typedef const nsStyleStruct*
   (nsRuleNode::*ComputeStyleDataFn)(nsStyleStruct* aStartStruct,
                                     const nsRuleDataStruct& aStartData,
-                                    nsIStyleContext* aContext,
+                                    nsStyleContext* aContext,
                                     nsRuleNode* aHighestNode,
                                     const RuleDetail& aRuleDetail,
                                     PRBool aInherited);
@@ -509,33 +509,33 @@ protected:
   inline RuleDetail CheckSpecifiedProperties(const nsStyleStructID aSID, const nsRuleDataStruct& aRuleDataStruct);
 
   const nsStyleStruct* GetParentData(const nsStyleStructID aSID);
-  const nsStyleStruct* GetDisplayData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetVisibilityData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetFontData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetColorData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetBackgroundData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetMarginData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetBorderData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetPaddingData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetOutlineData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetListData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetPositionData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetTableData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetTableBorderData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetContentData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetQuotesData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetTextData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetTextResetData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetUserInterfaceData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetUIResetData(nsIStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetDisplayData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetVisibilityData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetFontData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetColorData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetBackgroundData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetMarginData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetBorderData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetPaddingData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetOutlineData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetListData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetPositionData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetTableData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetTableBorderData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetContentData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetQuotesData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetTextData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetTextResetData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetUserInterfaceData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetUIResetData(nsStyleContext* aContext, PRBool aComputeData);
 #ifdef INCLUDE_XUL
-  const nsStyleStruct* GetXULData(nsIStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetXULData(nsStyleContext* aContext, PRBool aComputeData);
 #endif
 #ifdef MOZ_SVG
-  const nsStyleStruct* GetSVGData(nsIStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetSVGData(nsStyleContext* aContext, PRBool aComputeData);
 #endif
 
-  typedef const nsStyleStruct* (nsRuleNode::*GetStyleDataFn)(nsIStyleContext*, PRBool);
+  typedef const nsStyleStruct* (nsRuleNode::*GetStyleDataFn)(nsStyleContext*, PRBool);
   static GetStyleDataFn gGetStyleDataFn[];
 
 public:
@@ -568,7 +568,7 @@ public:
   nsresult GetPresContext(nsIPresContext** aResult);
   nsresult PathContainsRule(nsIStyleRule* aRule, PRBool* aMatched);
   const nsStyleStruct* GetStyleData(nsStyleStructID aSID, 
-                                    nsIStyleContext* aContext,
+                                    nsStyleContext* aContext,
                                     PRBool aComputeData);
 };
 
diff --git a/mozilla/content/shared/public/nsStyleContext.h b/mozilla/content/shared/public/nsStyleContext.h
new file mode 100644
index 00000000000..974f6bb87eb
--- /dev/null
+++ b/mozilla/content/shared/public/nsStyleContext.h
@@ -0,0 +1,159 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: NPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is 
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1998
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   David Hyatt <hyatt@netscape.com>
+ *   Pierre Phaneuf <pp@ludusdesign.com>
+ *
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the NPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the NPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef _nsStyleContext_h_
+#define _nsStyleContext_h_
+
+#include "nsRuleNode.h"
+
+class nsIPresContext;
+class nsIAtom;
+
+class nsStyleContext
+{
+public:
+  nsStyleContext(nsStyleContext* aParent, nsIAtom* aPseudoTag, 
+                 nsRuleNode* aRuleNode, nsIPresContext* aPresContext);
+  ~nsStyleContext();
+
+  void* operator new(size_t sz, nsIPresContext* aPresContext) CPP_THROW_NEW;
+  void Destroy();
+
+  void AddRef() {
+    ++mRefCnt;
+    NS_LOG_ADDREF(this, mRefCnt, "nsStyleContext", sizeof(nsStyleContext));
+  }
+
+  void Release() {
+    --mRefCnt;
+    NS_LOG_RELEASE(this, mRefCnt, "nsStyleContext");
+    if (mRefCnt == 0) {
+      mRefCnt = 1;
+      Destroy();
+    }
+  }
+
+  nsStyleContext* GetParent() const { return mParent; }
+
+  nsStyleContext* GetFirstChild() const { return mChild; }
+
+  already_AddRefed<nsIAtom> GetPseudoType() const;
+
+  already_AddRefed<nsStyleContext> 
+  FindChildWithRules(const nsIAtom* aPseudoTag, nsRuleNode* aRules);
+
+  PRBool    Equals(const nsStyleContext* aOther) const;
+  PRBool    HasTextDecorations() { return mBits & NS_STYLE_HAS_TEXT_DECORATIONS; };
+
+  void GetBorderPaddingFor(nsStyleBorderPadding& aBorderPadding);
+
+  void SetStyle(nsStyleStructID aSID, nsStyleStruct* aStruct);
+
+  void GetRuleNode(nsRuleNode** aResult) { *aResult = mRuleNode; }
+  void AddStyleBit(const PRUint32& aBit) { mBits |= aBit; }
+  void GetStyleBits(PRUint32* aBits) { *aBits = mBits; }
+
+  const nsStyleStruct* GetStyleData(nsStyleStructID aSID);
+  const nsStyleStruct* PeekStyleData(nsStyleStructID aSID);
+
+  nsStyleStruct* GetUniqueStyleData(nsIPresContext* aPresContext, const nsStyleStructID& aSID);
+
+  void ClearCachedDataForRule(nsIStyleRule* aRule);
+
+  void ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule);
+
+  nsChangeHint CalcStyleDifference(nsStyleContext* aOther);
+
+#ifdef DEBUG
+  void DumpRegressionData(nsIPresContext* aPresContext, FILE* out, PRInt32 aIndent);
+
+  void List(FILE* out, PRInt32 aIndent);
+
+  void SizeOf(nsISizeOfHandler *aSizeOfHandler, PRUint32 &aSize);
+#endif
+
+protected:
+  void AppendChild(nsStyleContext* aChild);
+  void RemoveChild(nsStyleContext* aChild);
+
+  void ApplyStyleFixups(nsIPresContext* aPresContext);
+
+  nsStyleContext* mParent;
+  nsStyleContext* mChild;
+  nsStyleContext* mEmptyChild;
+  nsStyleContext* mPrevSibling;
+  nsStyleContext* mNextSibling;
+
+  // If this style context is for a pseudo-element, the pseudo-element
+  // atom.  Otherwise, null.
+  nsCOMPtr<nsIAtom> mPseudoTag;
+
+  nsRuleNode*             mRuleNode;
+
+  // |mCachedStyleData| points to both structs that are owned by this
+  // style context and structs that are owned by one of this style
+  // context's ancestors (which are indirectly owned since this style
+  // context owns a reference to its parent).  If the bit in |mBits| is
+  // set for a struct, that means that the pointer for that struct is
+  // owned by an ancestor rather than by this style context.
+  nsCachedStyleData       mCachedStyleData; // Our cached style data.
+  PRUint32                mBits; // Which structs are inherited from the
+                                 // parent context.
+  PRUint32                mRefCnt;
+};
+
+already_AddRefed<nsStyleContext>
+NS_NewStyleContext(nsStyleContext* aParentContext,
+                   nsIAtom* aPseudoTag,
+                   nsRuleNode* aRuleNode,
+                   nsIPresContext* aPresContext);
+
+
+// typesafe way to access style data.  See nsStyleStruct.h and also
+// overloaded function in nsIFrame.h.
+template <class T>
+inline void
+GetStyleData(nsStyleContext* aStyleContext, const T** aStyleStruct)
+{
+    *aStyleStruct = NS_STATIC_CAST(const T*,
+                         aStyleContext->GetStyleData(NS_GET_STYLESTRUCTID(T)));
+}
+
+#endif
diff --git a/mozilla/content/shared/public/nsStyleStruct.h b/mozilla/content/shared/public/nsStyleStruct.h
index dd99d7931b8..92935245f44 100644
--- a/mozilla/content/shared/public/nsStyleStruct.h
+++ b/mozilla/content/shared/public/nsStyleStruct.h
@@ -1219,7 +1219,7 @@ inline nsBorderEdges::nsBorderEdges()
 
 // typesafe mechanisms for accessing style data, global function
 // templates |GetStyleData(nsIFrame*, const T**)| and
-// |GetStyleData(nsIStyleContext*, const T**)|, where T is derived from
-// nsStyleStruct, are located in nsIStyleContext.h and nsIFrame.h
+// |GetStyleData(nsStyleContext*, const T**)|, where T is derived from
+// nsStyleStruct, are located in nsStyleContext.h and nsIFrame.h
 
 #endif /* nsStyleStruct_h___ */
diff --git a/mozilla/content/shared/src/nsStyleStruct.cpp b/mozilla/content/shared/src/nsStyleStruct.cpp
index 49e83428e16..2ab1fa3fc69 100644
--- a/mozilla/content/shared/src/nsStyleStruct.cpp
+++ b/mozilla/content/shared/src/nsStyleStruct.cpp
@@ -78,8 +78,7 @@ inline nscoord CalcSideFor(const nsIFrame* aFrame, const nsStyleCoord& aCoord,
       nsIFrame* parentFrame;
       aFrame->GetParent(&parentFrame);  // XXX may not be direct parent...
       if (nsnull != parentFrame) {
-        nsIStyleContext* parentContext;
-        parentFrame->GetStyleContext(&parentContext);
+        nsStyleContext* parentContext = parentFrame->GetStyleContext();
         if (nsnull != parentContext) {
           nsMargin  parentSpacing;
           switch (aSpacing) {
@@ -111,7 +110,6 @@ inline nscoord CalcSideFor(const nsIFrame* aFrame, const nsStyleCoord& aCoord,
             case NS_SIDE_RIGHT:   result = parentSpacing.right;  break;
             case NS_SIDE_BOTTOM:  result = parentSpacing.bottom; break;
           }
-          NS_RELEASE(parentContext);
         }
       }
       break;
diff --git a/mozilla/content/xbl/src/nsXBLResourceLoader.cpp b/mozilla/content/xbl/src/nsXBLResourceLoader.cpp
index dd548bcf1aa..6120ffffccb 100644
--- a/mozilla/content/xbl/src/nsXBLResourceLoader.cpp
+++ b/mozilla/content/xbl/src/nsXBLResourceLoader.cpp
@@ -57,7 +57,7 @@
 #include "nsXBLAtoms.h"
 #include "nsINameSpaceManager.h"
 #include "nsIFrameManager.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 
 NS_IMPL_ISUPPORTS1(nsXBLResourceLoader, nsICSSLoaderObserver)
 
@@ -279,8 +279,7 @@ nsXBLResourceLoader::NotifyBoundElements()
             // Check to see if it's in the undisplayed content map.
             nsCOMPtr<nsIFrameManager> frameManager;
             shell->GetFrameManager(getter_AddRefs(frameManager));
-            nsCOMPtr<nsIStyleContext> sc;
-            frameManager->GetUndisplayedContent(content, getter_AddRefs(sc));
+            nsStyleContext* sc = frameManager->GetUndisplayedContent(content);
             if (!sc) {
               nsCOMPtr<nsIDocumentObserver> obs(do_QueryInterface(shell));
               obs->ContentInserted(doc, parent, content, index);
diff --git a/mozilla/content/xbl/src/nsXBLService.cpp b/mozilla/content/xbl/src/nsXBLService.cpp
index b8319f8b67a..762307d1d50 100644
--- a/mozilla/content/xbl/src/nsXBLService.cpp
+++ b/mozilla/content/xbl/src/nsXBLService.cpp
@@ -88,7 +88,7 @@
 #include "nsIPresShell.h"
 #include "nsIDocumentObserver.h"
 #include "nsIFrameManager.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 
 #include "nsIXULPrototypeCache.h"
 #include "nsIDOMLoadListener.h"
@@ -173,8 +173,7 @@ public:
         // Check to see if it's in the undisplayed content map.
         nsCOMPtr<nsIFrameManager> frameManager;
         shell->GetFrameManager(getter_AddRefs(frameManager));
-        nsCOMPtr<nsIStyleContext> sc;
-        frameManager->GetUndisplayedContent(mBoundElement, getter_AddRefs(sc));
+        nsStyleContext* sc = frameManager->GetUndisplayedContent(mBoundElement);
         if (!sc) {
           nsCOMPtr<nsIDocumentObserver> obs(do_QueryInterface(shell));
           obs->ContentInserted(doc, parent, mBoundElement, index);
diff --git a/mozilla/content/xul/content/src/nsXULElement.cpp b/mozilla/content/xul/content/src/nsXULElement.cpp
index ec0c4d3de45..dcd32f1ee36 100644
--- a/mozilla/content/xul/content/src/nsXULElement.cpp
+++ b/mozilla/content/xul/content/src/nsXULElement.cpp
@@ -148,6 +148,7 @@
 #include "nsISizeOfHandler.h"
 #include "nsReadableUtils.h"
 #include "nsITimelineService.h"
+#include "nsIFrame.h"
 
 class nsIWebShell;
 
diff --git a/mozilla/editor/libeditor/html/nsHTMLEditRules.cpp b/mozilla/editor/libeditor/html/nsHTMLEditRules.cpp
index e7879d8abde..87db5aa0ff4 100644
--- a/mozilla/editor/libeditor/html/nsHTMLEditRules.cpp
+++ b/mozilla/editor/libeditor/html/nsHTMLEditRules.cpp
@@ -52,7 +52,7 @@
 #include "TypeInState.h"
 
 #include "nsIServiceManager.h"
-
+#include "nsCRT.h"
 #include "nsIContent.h"
 #include "nsIContentIterator.h"
 #include "nsIDOMNode.h"
@@ -66,7 +66,6 @@
 #include "nsIDOMNSRange.h"
 #include "nsIDOMCharacterData.h"
 #include "nsIEnumerator.h"
-#include "nsIStyleContext.h"
 #include "nsIPresShell.h"
 #include "nsLayoutCID.h"
 #include "nsIPrefBranch.h"
diff --git a/mozilla/layout/base/nsBidiPresUtils.cpp b/mozilla/layout/base/nsBidiPresUtils.cpp
index ed37179c4eb..0e8bd493d5f 100644
--- a/mozilla/layout/base/nsBidiPresUtils.cpp
+++ b/mozilla/layout/base/nsBidiPresUtils.cpp
@@ -126,14 +126,13 @@ CreateBidiContinuation(nsIPresContext* aPresContext,
   if (!(*aNewFrame) ) {
     return NS_ERROR_OUT_OF_MEMORY;
   }
-  nsCOMPtr<nsIStyleContext> styleContext;
-  aFrame->GetStyleContext(getter_AddRefs(styleContext) );
+  nsStyleContext* styleContext = aFrame->GetStyleContext();
 
-  NS_ASSERTION(presShell, "Frame has no styleContext in nsBidiPresUtils::CreateBidiContinuation");
+  NS_ASSERTION(styleContext, "Frame has no styleContext in nsBidiPresUtils::CreateBidiContinuation");
   
   aFrame->GetParent(&parent);
 
-  NS_ASSERTION(presShell, "Couldn't get frame parent in nsBidiPresUtils::CreateBidiContinuation");
+  NS_ASSERTION(parent, "Couldn't get frame parent in nsBidiPresUtils::CreateBidiContinuation");
 
   (*aNewFrame)->Init(aPresContext, aContent, parent, styleContext, nsnull);
 
diff --git a/mozilla/layout/base/nsCSSFrameConstructor.cpp b/mozilla/layout/base/nsCSSFrameConstructor.cpp
index dbf07098ab9..e50f0b19b51 100644
--- a/mozilla/layout/base/nsCSSFrameConstructor.cpp
+++ b/mozilla/layout/base/nsCSSFrameConstructor.cpp
@@ -114,6 +114,7 @@
 #include "nsCSSRendering.h"
 #include "nsISelectElement.h"
 #include "nsLayoutErrors.h"
+#include "nsAutoPtr.h"
 
 static NS_DEFINE_CID(kTextNodeCID,   NS_TEXTNODE_CID);
 static NS_DEFINE_CID(kHTMLElementFactoryCID,   NS_HTML_ELEMENT_FACTORY_CID);
@@ -1024,7 +1025,7 @@ AdjustOutOfFlowFrameParentPtrs(nsIPresContext*          aPresContext,
  */
 static void
 MoveChildrenTo(nsIPresContext*          aPresContext,
-               nsIStyleContext*         aNewParentSC,
+               nsStyleContext*          aNewParentSC,
                nsIFrame*                aNewParent,
                nsIFrame*                aFrameList,
                nsFrameConstructorState* aState)
@@ -1376,7 +1377,7 @@ nsCSSFrameConstructor::CreateGeneratedFrameFor(nsIPresContext*       aPresContex
                                                nsIDocument*          aDocument,
                                                nsIFrame*             aParentFrame,
                                                nsIContent*           aContent,
-                                               nsIStyleContext*      aStyleContext,
+                                               nsStyleContext*       aStyleContext,
                                                const nsStyleContent* aStyleContent,
                                                PRUint32              aContentIndex,
                                                nsIFrame**            aFrame)
@@ -1568,7 +1569,7 @@ nsCSSFrameConstructor::CreateGeneratedContentFrame(nsIPresShell*        aPresShe
                                                    nsFrameConstructorState& aState,
                                                    nsIFrame*        aFrame,
                                                    nsIContent*      aContent,
-                                                   nsIStyleContext* aStyleContext,
+                                                   nsStyleContext*  aStyleContext,
                                                    nsIAtom*         aPseudoElement,
                                                    nsIFrame**       aWrapperFrame,
                                                    nsIFrame**       aResult)
@@ -1579,9 +1580,10 @@ nsCSSFrameConstructor::CreateGeneratedContentFrame(nsIPresShell*        aPresShe
     return PR_FALSE;
 
   // Probe for the existence of the pseudo-element
-  nsCOMPtr<nsIStyleContext> pseudoStyleContext;
-  aPresContext->ProbePseudoStyleContextFor(aContent, aPseudoElement, aStyleContext,
-                                           getter_AddRefs(pseudoStyleContext));
+  nsRefPtr<nsStyleContext> pseudoStyleContext;
+  pseudoStyleContext = aPresContext->ProbePseudoStyleContextFor(aContent,
+                                                                aPseudoElement,
+                                                                aStyleContext);
 
   if (pseudoStyleContext) {
     const nsStyleDisplay* display;
@@ -1609,10 +1611,11 @@ nsCSSFrameConstructor::CreateGeneratedContentFrame(nsIPresShell*        aPresShe
               NS_NewInlineFrame(aPresShell, aWrapperFrame);
               wrapperPseudo = nsCSSAnonBoxes::mozGCWrapperInline;
             }        
-            nsCOMPtr<nsIStyleContext> parentSC = aStyleContext->GetParent(); 
-            nsCOMPtr<nsIStyleContext> wrapperSC;
-            aPresContext->ResolvePseudoStyleContextFor(nsnull, wrapperPseudo,
-                                          parentSC, getter_AddRefs(wrapperSC));
+            nsStyleContext* parentSC = aStyleContext->GetParent();
+            nsRefPtr<nsStyleContext> wrapperSC;
+            wrapperSC = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                   wrapperPseudo,
+                                                                   parentSC);
             // |aFrame| is already the correct parent.
             InitAndRestoreFrame(aPresContext, aState, aContent, aFrame,
                                 wrapperSC, nsnull, *aWrapperFrame);
@@ -1643,9 +1646,8 @@ nsCSSFrameConstructor::CreateGeneratedContentFrame(nsIPresShell*        aPresShe
 
         // Create another pseudo style context to use for all the generated child
         // frames
-        nsIStyleContext*  textStyleContext;
-        aPresContext->ResolveStyleContextForNonElement(pseudoStyleContext,
-                                                       &textStyleContext);
+        nsRefPtr<nsStyleContext> textStyleContext;
+        textStyleContext = aPresContext->ResolveStyleContextForNonElement(pseudoStyleContext);
 
         // Now create content objects (and child frames) for each value of the
         // 'content' property
@@ -1665,7 +1667,6 @@ nsCSSFrameConstructor::CreateGeneratedContentFrame(nsIPresShell*        aPresShe
           }
         }
   
-        NS_RELEASE(textStyleContext);
         if (childFrames.childList) {
           containerFrame->SetInitialChildList(aPresContext, nsnull, childFrames.childList);
         }
@@ -1683,7 +1684,7 @@ nsCSSFrameConstructor::CreateInputFrame(nsIPresShell    *aPresShell,
                                         nsIPresContext  *aPresContext,
                                         nsIContent      *aContent, 
                                         nsIFrame        *&aFrame,
-                                        nsIStyleContext *aStyleContext)
+                                        nsStyleContext  *aStyleContext)
 {
   nsCOMPtr<nsIFormControl> control = do_QueryInterface(aContent);
   NS_ASSERTION(control, "input is not an nsIFormControl!");
@@ -1991,18 +1992,17 @@ nsCSSFrameConstructor::CreatePseudoTableFrame(nsIPresShell*            aPresShel
                           ? aState.mPseudoFrames.mCellInner.mFrame : aParentFrameIn;
   if (!parentFrame) return rv;
 
-  nsCOMPtr<nsIStyleContext> parentStyle;
   nsCOMPtr<nsIContent>      parentContent;
-  nsCOMPtr<nsIStyleContext> childStyle;
+  nsStyleContext *parentStyle;
+  nsRefPtr<nsStyleContext> childStyle;
 
-  parentFrame->GetStyleContext(getter_AddRefs(parentStyle)); 
+  parentStyle = parentFrame->GetStyleContext(); 
   parentFrame->GetContent(getter_AddRefs(parentContent));   
 
   // create the SC for the inner table which will be the parent of the outer table's SC
-  aPresContext->ResolvePseudoStyleContextFor(parentContent,
-                                             nsCSSAnonBoxes::table,
-                                             parentStyle,
-                                             getter_AddRefs(childStyle));
+  childStyle = aPresContext->ResolvePseudoStyleContextFor(parentContent,
+                                                          nsCSSAnonBoxes::table,
+                                                          parentStyle);
 
   nsPseudoFrameData& pseudoOuter = aState.mPseudoFrames.mTableOuter;
   nsPseudoFrameData& pseudoInner = aState.mPseudoFrames.mTableInner;
@@ -2011,7 +2011,7 @@ nsCSSFrameConstructor::CreatePseudoTableFrame(nsIPresShell*            aPresShel
   PRBool pseudoParent;
   nsFrameItems items;
   rv = ConstructTableFrame(aPresShell, aPresContext, aState, parentContent,
-                           parentFrame, childStyle.get(), aTableCreator,
+                           parentFrame, childStyle, aTableCreator,
                            PR_TRUE, items, pseudoOuter.mFrame, 
                            pseudoInner.mFrame, pseudoParent);
 
@@ -2042,17 +2042,16 @@ nsCSSFrameConstructor::CreatePseudoRowGroupFrame(nsIPresShell*            aPresS
                           ? aState.mPseudoFrames.mTableInner.mFrame : aParentFrameIn;
   if (!parentFrame) return rv;
 
-  nsCOMPtr<nsIStyleContext> parentStyle;
   nsCOMPtr<nsIContent>      parentContent;
-  nsCOMPtr<nsIStyleContext> childStyle;
+  nsStyleContext *parentStyle;
+  nsRefPtr<nsStyleContext> childStyle;
 
-  parentFrame->GetStyleContext(getter_AddRefs(parentStyle)); 
+  parentStyle = parentFrame->GetStyleContext();
   parentFrame->GetContent(getter_AddRefs(parentContent));   
 
-  aPresContext->ResolvePseudoStyleContextFor(parentContent,
-                                             nsCSSAnonBoxes::tableRowGroup, 
-                                             parentStyle,
-                                             getter_AddRefs(childStyle));
+  childStyle = aPresContext->ResolvePseudoStyleContextFor(parentContent,
+                                                          nsCSSAnonBoxes::tableRowGroup, 
+                                                          parentStyle);
 
   nsPseudoFrameData& pseudo = aState.mPseudoFrames.mRowGroup;
 
@@ -2060,7 +2059,7 @@ nsCSSFrameConstructor::CreatePseudoRowGroupFrame(nsIPresShell*            aPresS
   PRBool pseudoParent;
   nsFrameItems items;
   rv = ConstructTableRowGroupFrame(aPresShell, aPresContext, aState, parentContent,
-                                   parentFrame, childStyle.get(), aTableCreator,
+                                   parentFrame, childStyle, aTableCreator,
                                    PR_TRUE, items, pseudo.mFrame, pseudoParent);
   if (NS_FAILED(rv)) return rv;
 
@@ -2088,17 +2087,16 @@ nsCSSFrameConstructor::CreatePseudoColGroupFrame(nsIPresShell*            aPresS
                           ? aState.mPseudoFrames.mTableInner.mFrame : aParentFrameIn;
   if (!parentFrame) return rv;
 
-  nsCOMPtr<nsIStyleContext> parentStyle;
   nsCOMPtr<nsIContent>      parentContent;
-  nsCOMPtr<nsIStyleContext> childStyle;
+  nsStyleContext *parentStyle;
+  nsRefPtr<nsStyleContext> childStyle;
 
-  parentFrame->GetStyleContext(getter_AddRefs(parentStyle)); 
+  parentStyle = parentFrame->GetStyleContext();
   parentFrame->GetContent(getter_AddRefs(parentContent));   
 
-  aPresContext->ResolvePseudoStyleContextFor(parentContent,
-                                             nsCSSAnonBoxes::tableColGroup, 
-                                             parentStyle,
-                                             getter_AddRefs(childStyle));
+  childStyle = aPresContext->ResolvePseudoStyleContextFor(parentContent,
+                                                          nsCSSAnonBoxes::tableColGroup, 
+                                                          parentStyle);
 
   nsPseudoFrameData& pseudo = aState.mPseudoFrames.mColGroup;
 
@@ -2106,7 +2104,7 @@ nsCSSFrameConstructor::CreatePseudoColGroupFrame(nsIPresShell*            aPresS
   PRBool pseudoParent;
   nsFrameItems items;
   rv = ConstructTableColGroupFrame(aPresShell, aPresContext, aState, parentContent,
-                                   parentFrame, childStyle.get(), aTableCreator,
+                                   parentFrame, childStyle, aTableCreator,
                                    PR_TRUE, items, pseudo.mFrame, pseudoParent);
   if (NS_FAILED(rv)) return rv;
   ((nsTableColGroupFrame*)pseudo.mFrame)->SetType(eColGroupAnonymousCol);
@@ -2132,17 +2130,16 @@ nsCSSFrameConstructor::CreatePseudoRowFrame(nsIPresShell*            aPresShell,
                           ? aState.mPseudoFrames.mRowGroup.mFrame : aParentFrameIn;
   if (!parentFrame) return rv;
 
-  nsCOMPtr<nsIStyleContext> parentStyle;
   nsCOMPtr<nsIContent>      parentContent;
-  nsCOMPtr<nsIStyleContext> childStyle;
+  nsStyleContext *parentStyle;
+  nsRefPtr<nsStyleContext> childStyle;
 
-  parentFrame->GetStyleContext(getter_AddRefs(parentStyle)); 
+  parentStyle = parentFrame->GetStyleContext();
   parentFrame->GetContent(getter_AddRefs(parentContent));   
 
-  aPresContext->ResolvePseudoStyleContextFor(parentContent,
-                                             nsCSSAnonBoxes::tableRow, 
-                                             parentStyle,
-                                             getter_AddRefs(childStyle));
+  childStyle = aPresContext->ResolvePseudoStyleContextFor(parentContent,
+                                                          nsCSSAnonBoxes::tableRow, 
+                                                          parentStyle);
 
   nsPseudoFrameData& pseudo = aState.mPseudoFrames.mRow;
 
@@ -2150,7 +2147,7 @@ nsCSSFrameConstructor::CreatePseudoRowFrame(nsIPresShell*            aPresShell,
   PRBool pseudoParent;
   nsFrameItems items;
   rv = ConstructTableRowFrame(aPresShell, aPresContext, aState, parentContent,
-                              parentFrame, childStyle.get(), aTableCreator,
+                              parentFrame, childStyle, aTableCreator,
                               PR_TRUE, items, pseudo.mFrame, pseudoParent);
   if (NS_FAILED(rv)) return rv;
 
@@ -2177,17 +2174,16 @@ nsCSSFrameConstructor::CreatePseudoCellFrame(nsIPresShell*            aPresShell
                           ? aState.mPseudoFrames.mRow.mFrame : aParentFrameIn;
   if (!parentFrame) return rv;
 
-  nsCOMPtr<nsIStyleContext> parentStyle;
   nsCOMPtr<nsIContent>      parentContent;
-  nsCOMPtr<nsIStyleContext> childStyle;
+  nsStyleContext *parentStyle;
+  nsRefPtr<nsStyleContext> childStyle;
 
-  parentFrame->GetStyleContext(getter_AddRefs(parentStyle)); 
+  parentStyle = parentFrame->GetStyleContext();
   parentFrame->GetContent(getter_AddRefs(parentContent));   
 
-  aPresContext->ResolvePseudoStyleContextFor(parentContent,
-                                             nsCSSAnonBoxes::tableCell, 
-                                             parentStyle,
-                                             getter_AddRefs(childStyle));
+  childStyle = aPresContext->ResolvePseudoStyleContextFor(parentContent,
+                                                          nsCSSAnonBoxes::tableCell, 
+                                                          parentStyle);
 
   nsPseudoFrameData& pseudoOuter = aState.mPseudoFrames.mCellOuter;
   nsPseudoFrameData& pseudoInner = aState.mPseudoFrames.mCellInner;
@@ -2196,7 +2192,7 @@ nsCSSFrameConstructor::CreatePseudoCellFrame(nsIPresShell*            aPresShell
   PRBool pseudoParent;
   nsFrameItems items;
   rv = ConstructTableCellFrame(aPresShell, aPresContext, aState, parentContent,
-                               parentFrame, childStyle.get(), aTableCreator,
+                               parentFrame, childStyle, aTableCreator,
                                PR_TRUE, items, pseudoOuter.mFrame, 
                                pseudoInner.mFrame, pseudoParent);
   if (NS_FAILED(rv)) return rv;
@@ -2528,7 +2524,7 @@ nsCSSFrameConstructor::ConstructTableFrame(nsIPresShell*            aPresShell,
                                            nsFrameConstructorState& aState,
                                            nsIContent*              aContent,
                                            nsIFrame*                aParentFrameIn,
-                                           nsIStyleContext*         aStyleContext,
+                                           nsStyleContext*          aStyleContext,
                                            nsTableCreator&          aTableCreator,
                                            PRBool                   aIsPseudo,
                                            nsFrameItems&            aChildItems,
@@ -2557,11 +2553,10 @@ nsCSSFrameConstructor::ConstructTableFrame(nsIPresShell*            aPresShell,
   }
 
   // create the pseudo SC for the outer table as a child of the inner SC
-  nsCOMPtr<nsIStyleContext> outerStyleContext;
-  aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                             nsCSSAnonBoxes::tableOuter,
-                                             aStyleContext,
-                                             getter_AddRefs(outerStyleContext));
+  nsRefPtr<nsStyleContext> outerStyleContext;
+  outerStyleContext = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                                 nsCSSAnonBoxes::tableOuter,
+                                                                 aStyleContext);
   
   // Init the table outer frame and see if we need to create a view, e.g.
   // the frame is absolutely positioned  
@@ -2610,7 +2605,7 @@ nsCSSFrameConstructor::ConstructTableCaptionFrame(nsIPresShell*            aPres
                                                   nsFrameConstructorState& aState,
                                                   nsIContent*              aContent,
                                                   nsIFrame*                aParentFrameIn,
-                                                  nsIStyleContext*         aStyleContext,
+                                                  nsStyleContext*          aStyleContext,
                                                   nsTableCreator&          aTableCreator,
                                                   nsFrameItems&            aChildItems,
                                                   nsIFrame*&               aNewFrame,
@@ -2656,7 +2651,7 @@ nsCSSFrameConstructor::ConstructTableRowGroupFrame(nsIPresShell*            aPre
                                                    nsFrameConstructorState& aState,
                                                    nsIContent*              aContent,
                                                    nsIFrame*                aParentFrameIn,
-                                                   nsIStyleContext*         aStyleContext,
+                                                   nsStyleContext*          aStyleContext,
                                                    nsTableCreator&          aTableCreator,
                                                    PRBool                   aIsPseudo,
                                                    nsFrameItems&            aChildItems,
@@ -2731,7 +2726,7 @@ nsCSSFrameConstructor::ConstructTableColGroupFrame(nsIPresShell*            aPre
                                                    nsFrameConstructorState& aState,
                                                    nsIContent*              aContent,
                                                    nsIFrame*                aParentFrameIn,
-                                                   nsIStyleContext*         aStyleContext,
+                                                   nsStyleContext*          aStyleContext,
                                                    nsTableCreator&          aTableCreator,
                                                    PRBool                   aIsPseudo,
                                                    nsFrameItems&            aChildItems,
@@ -2781,7 +2776,7 @@ nsCSSFrameConstructor::ConstructTableRowFrame(nsIPresShell*            aPresShel
                                               nsFrameConstructorState& aState,
                                               nsIContent*              aContent,
                                               nsIFrame*                aParentFrameIn,
-                                              nsIStyleContext*         aStyleContext,
+                                              nsStyleContext*          aStyleContext,
                                               nsTableCreator&          aTableCreator,
                                               PRBool                   aIsPseudo,
                                               nsFrameItems&            aChildItems,
@@ -2836,7 +2831,7 @@ nsCSSFrameConstructor::ConstructTableColFrame(nsIPresShell*            aPresShel
                                               nsFrameConstructorState& aState,
                                               nsIContent*              aContent,
                                               nsIFrame*                aParentFrameIn,
-                                              nsIStyleContext*         aStyleContext,
+                                              nsStyleContext*          aStyleContext,
                                               nsTableCreator&          aTableCreator,
                                               PRBool                   aIsPseudo,
                                               nsFrameItems&            aChildItems,
@@ -2860,8 +2855,7 @@ nsCSSFrameConstructor::ConstructTableColFrame(nsIPresShell*            aPresShel
   rv = aTableCreator.CreateTableColFrame(&aNewFrame); if (NS_FAILED(rv)) return rv;
   InitAndRestoreFrame(aPresContext, aState, aContent, parentFrame, aStyleContext, nsnull, aNewFrame);
   // if the parent frame was anonymous then reparent the style context
-  nsCOMPtr<nsIStyleContext> parentStyleContext;
-  parentFrame->GetStyleContext(getter_AddRefs(parentStyleContext));
+  nsStyleContext* parentStyleContext = parentFrame->GetStyleContext();
   if (aIsPseudoParent) {
     aPresContext->ReParentStyleContext(aNewFrame, parentStyleContext);
   }
@@ -2872,11 +2866,11 @@ nsCSSFrameConstructor::ConstructTableColFrame(nsIPresShell*            aPresShel
   if (cgContent) { 
     cgContent->GetSpan(&span);
     nsIFrame* lastCol = aNewFrame;
-    nsCOMPtr<nsIStyleContext> styleContext;
+    nsStyleContext* styleContext;
     for (PRInt32 spanX = 1; spanX < span; spanX++) {
       // The same content node should always resolve to the same style context.
       if (1 == spanX)
-        aNewFrame->GetStyleContext(getter_AddRefs(styleContext));
+        styleContext = aNewFrame->GetStyleContext();
       nsIFrame* newCol;
       rv = aTableCreator.CreateTableColFrame(&newCol); if (NS_FAILED(rv)) return rv;
       InitAndRestoreFrame(aPresContext, aState, aContent, parentFrame,
@@ -2908,7 +2902,7 @@ nsCSSFrameConstructor::ConstructTableCellFrame(nsIPresShell*            aPresShe
                                                nsFrameConstructorState& aState,
                                                nsIContent*              aContent,
                                                nsIFrame*                aParentFrameIn,
-                                               nsIStyleContext*         aStyleContext,
+                                               nsStyleContext*          aStyleContext,
                                                nsTableCreator&          aTableCreator,
                                                PRBool                   aIsPseudo,
                                                nsFrameItems&            aChildItems,
@@ -2953,11 +2947,10 @@ nsCSSFrameConstructor::ConstructTableCellFrame(nsIPresShell*            aPresShe
   }
   
   // Resolve pseudo style and initialize the body cell frame
-  nsCOMPtr<nsIStyleContext> innerPseudoStyle;
-  aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                             nsCSSAnonBoxes::cellContent,
-                                             aStyleContext,
-                                             getter_AddRefs(innerPseudoStyle));
+  nsRefPtr<nsStyleContext> innerPseudoStyle;
+  innerPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                                nsCSSAnonBoxes::cellContent,
+                                                                aStyleContext);
   InitAndRestoreFrame(aPresContext, aState, aContent, 
                       aNewCellOuterFrame, innerPseudoStyle, nsnull, aNewCellInnerFrame);
 
@@ -2998,7 +2991,7 @@ nsCSSFrameConstructor::MustGeneratePseudoParent(nsIPresContext*  aPresContext,
                                                 nsIFrame*        aParentFrame,
                                                 nsIAtom*         aTag,
                                                 nsIContent*      aContent,
-                                                nsIStyleContext* aStyleContext)
+                                                nsStyleContext*  aStyleContext)
 {
   if (!aStyleContext) return PR_FALSE;
 
@@ -3029,7 +3022,7 @@ nsCSSFrameConstructor::ConstructTableForeignFrame(nsIPresShell*            aPres
                                                   nsFrameConstructorState& aState,
                                                   nsIContent*              aContent,
                                                   nsIFrame*                aParentFrameIn,
-                                                  nsIStyleContext*         aStyleContext,
+                                                  nsStyleContext*          aStyleContext,
                                                   nsTableCreator&          aTableCreator,
                                                   nsFrameItems&            aChildItems,
                                                   nsIFrame*&               aNewFrame,
@@ -3116,8 +3109,7 @@ nsCSSFrameConstructor::TableProcessChildren(nsIPresShell*            aPresShell,
 
   nsCOMPtr<nsIAtom> parentFrameType;
   aParentFrame->GetFrameType(getter_AddRefs(parentFrameType));
-  nsCOMPtr<nsIStyleContext> parentStyleContext;
-  aParentFrame->GetStyleContext(getter_AddRefs(parentStyleContext));
+  nsStyleContext* parentStyleContext = aParentFrame->GetStyleContext();
 
   ChildIterator iter, last;
   for (ChildIterator::Init(aContent, &iter, &last);
@@ -3153,7 +3145,7 @@ nsCSSFrameConstructor::TableProcessChild(nsIPresShell*            aPresShell,
                                          nsIContent*              aParentContent,
                                          nsIFrame*                aParentFrame,
                                          nsIAtom*                 aParentFrameType,
-                                         nsIStyleContext*         aParentStyleContext,
+                                         nsStyleContext*          aParentStyleContext,
                                          nsTableCreator&          aTableCreator,
                                          nsFrameItems&            aChildItems,
                                          nsIFrame*&               aCaption)
@@ -3164,11 +3156,11 @@ nsCSSFrameConstructor::TableProcessChild(nsIPresShell*            aPresShell,
   PRBool isPseudoParent = PR_FALSE;
     
   nsIFrame* childFrame = nsnull;
-  nsCOMPtr<nsIStyleContext> childStyleContext;
+  nsRefPtr<nsStyleContext> childStyleContext;
 
   // Resolve the style context and get its display
-  ResolveStyleContext(aPresContext, aParentFrame, aChildContent,
-                      getter_AddRefs(childStyleContext));
+  childStyleContext = ResolveStyleContext(aPresContext, aParentFrame,
+                                          aChildContent);
   const nsStyleDisplay* styleDisplay = (const nsStyleDisplay*)
     childStyleContext->GetStyleData(eStyleStruct_Display);
 
@@ -3294,8 +3286,7 @@ nsCSSFrameConstructor:: GetDisplay(nsIFrame* aFrame)
   if (nsnull == aFrame) {
     return nsnull;
   }
-  nsCOMPtr<nsIStyleContext> styleContext;
-  aFrame->GetStyleContext(getter_AddRefs(styleContext));
+  nsStyleContext* styleContext = aFrame->GetStyleContext();
   const nsStyleDisplay* display = 
     (const nsStyleDisplay*)styleContext->GetStyleData(eStyleStruct_Display);
   return display;
@@ -3334,7 +3325,7 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
                                                 nsFrameConstructorState& aState,
                                                 nsIContent*              aDocElement,
                                                 nsIFrame*                aParentFrame,
-                                                nsIStyleContext*         aParentStyleContext,
+                                                nsStyleContext*          aParentStyleContext,
                                                 nsIFrame*&               aNewFrame)
 {
     // how the root frame hierarchy should look
@@ -3405,9 +3396,9 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
   }
 
   // --------- CREATE AREA OR BOX FRAME -------
-  nsCOMPtr<nsIStyleContext>  styleContext;
-  aPresContext->ResolveStyleContextFor(aDocElement, aParentStyleContext,
-                                       getter_AddRefs(styleContext));
+  nsRefPtr<nsStyleContext> styleContext;
+  styleContext = aPresContext->ResolveStyleContextFor(aDocElement,
+                                                      aParentStyleContext);
 
   const nsStyleDisplay*  display = (const nsStyleDisplay*)
         styleContext->GetStyleData(eStyleStruct_Display);
@@ -3432,10 +3423,8 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
     }
 
     if (resolveStyle) {
-      rv = ResolveStyleContext(aPresContext, aParentFrame, aDocElement,
-                               getter_AddRefs(styleContext));
-      if (NS_FAILED(rv))
-        return rv;
+      styleContext = ResolveStyleContext(aPresContext, aParentFrame,
+                                         aDocElement);
     }
   }
 
@@ -3454,19 +3443,18 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
   // build a scrollframe
   if ((!isPaginated || (isPaginated && printPreviewContext)) && isScrollable) {
     nsIFrame* newScrollFrame = nsnull;
-    nsCOMPtr<nsIStyleContext> newContext;
+    nsRefPtr<nsStyleContext> newContext;
 
-    BeginBuildingScrollFrame( aPresShell, aPresContext,
-                              aState,
-                              aDocElement,
-                              styleContext,
-                              aParentFrame,
-                              nsCSSAnonBoxes::scrolledContent,
-                              mDocument,
-                              PR_FALSE,
-                              scrollFrame,
-                              newContext,
-                              newScrollFrame);
+    newContext = BeginBuildingScrollFrame( aPresShell, aPresContext,
+                                           aState,
+                                           aDocElement,
+                                           styleContext,
+                                           aParentFrame,
+                                           nsCSSAnonBoxes::scrolledContent,
+                                           mDocument,
+                                           PR_FALSE,
+                                           scrollFrame,
+                                           newScrollFrame);
 
     styleContext = newContext;
     aParentFrame = newScrollFrame;
@@ -3484,7 +3472,7 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
       if (NS_FAILED(rv)) {
         return rv;
       }
-      contentFrame->GetStyleContext(getter_AddRefs(styleContext));
+      styleContext = contentFrame->GetStyleContext();
   } else {
         // otherwise build a box or a block
 #if defined(MOZ_SVG)
@@ -3663,11 +3651,11 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
   
   // --------- BUILD VIEWPORT -----------
   nsIFrame*                 viewportFrame = nsnull;
-  nsCOMPtr<nsIStyleContext> viewportPseudoStyle;
+  nsRefPtr<nsStyleContext> viewportPseudoStyle;
 
-  aPresContext->ResolvePseudoStyleContextFor(nsnull, nsCSSAnonBoxes::viewport,
-                                           nsnull,
-                                           getter_AddRefs(viewportPseudoStyle));
+  viewportPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                   nsCSSAnonBoxes::viewport,
+                                                                   nsnull);
 
   NS_NewViewportFrame(aPresShell, &viewportFrame);
 
@@ -3804,9 +3792,8 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
     NS_ASSERTION(!isXUL, "XUL documents should never be scrollable - see above");
 
     // see if the style is overflow: hidden, first on the document element
-    nsCOMPtr<nsIStyleContext> styleContext;
-    aPresContext->ResolveStyleContextFor(aDocElement, nsnull,
-                                         getter_AddRefs(styleContext));
+    nsRefPtr<nsStyleContext> styleContext;
+    styleContext = aPresContext->ResolveStyleContextFor(aDocElement, nsnull);
     if (styleContext) {
       const nsStyleDisplay* display = (const nsStyleDisplay*)
         styleContext->GetStyleData(eStyleStruct_Display);
@@ -3846,9 +3833,9 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
         }
       }      
       if (bodyElement) {
-        nsCOMPtr<nsIStyleContext> bodyContext;
-        aPresContext->ResolveStyleContextFor(bodyElement, styleContext,
-                                             getter_AddRefs(bodyContext));
+        nsRefPtr<nsStyleContext> bodyContext;
+        bodyContext = aPresContext->ResolveStyleContextFor(bodyElement,
+                                                           styleContext);
         if (bodyContext) {
           const nsStyleDisplay* display = (const nsStyleDisplay*)
             bodyContext->GetStyleData(eStyleStruct_Display);
@@ -3864,7 +3851,7 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
   }
 
   nsIFrame* newFrame = rootFrame;
-  nsCOMPtr<nsIStyleContext> rootPseudoStyle;
+  nsRefPtr<nsStyleContext> rootPseudoStyle;
   // we must create a state because if the scrollbars are GFX it needs the 
   // state to build the scrollbar frames.
   nsFrameConstructorState state(aPresContext,
@@ -3876,9 +3863,9 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
 
   // If paginated, make sure we don't put scrollbars in
   if (isPaginated && !printPreviewContext)
-    aPresContext->ResolvePseudoStyleContextFor(nsnull, rootPseudo,
-                                               viewportPseudoStyle,
-                                               getter_AddRefs(rootPseudoStyle));
+    rootPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                 rootPseudo,
+                                                                 viewportPseudoStyle);
   else if (isScrollable) {
 
       // Build the frame. We give it the content we are wrapping which is the document,
@@ -3886,27 +3873,25 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
       // frame and the scrollable view if one was created.
 
       // resolve a context for the scrollframe
-      nsCOMPtr<nsIStyleContext>  styleContext;
-      aPresContext->ResolvePseudoStyleContextFor(nsnull,
-                                                 nsCSSAnonBoxes::viewportScroll,
-                                                 viewportPseudoStyle,
-                                                 getter_AddRefs(styleContext));
+      nsRefPtr<nsStyleContext>  styleContext;
+      styleContext = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                nsCSSAnonBoxes::viewportScroll,
+                                                                viewportPseudoStyle);
 
 
       nsIFrame* newScrollableFrame = nsnull;
 
-      BeginBuildingScrollFrame( aPresShell,
-                                aPresContext,
-                                state,
-                                aDocElement,
-                                styleContext,
-                                viewportFrame,
-                                rootPseudo,
-                                mDocument,
-                                PR_TRUE,
-                                newFrame,
-                                rootPseudoStyle,
-                                newScrollableFrame);
+      rootPseudoStyle = BeginBuildingScrollFrame( aPresShell,
+                                                  aPresContext,
+                                                  state,
+                                                  aDocElement,
+                                                  styleContext,
+                                                  viewportFrame,
+                                                  rootPseudo,
+                                                  mDocument,
+                                                  PR_TRUE,
+                                                  newFrame,
+                                                  newScrollableFrame);
 
       // Inform the view manager about the root scrollable view
       nsIView* view = nsnull;
@@ -3928,19 +3913,18 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
   } else {
     // If no scrollbars and xul, don't build a scrollframe at all. 
     if (isXUL) {
-      aPresContext->ResolvePseudoStyleContextFor(nsnull, rootPseudo,
-                                                 viewportPseudoStyle,
-                                                 getter_AddRefs(rootPseudoStyle));
+      rootPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                   rootPseudo,
+                                                                   viewportPseudoStyle);
     } else {
       // if HTML the always create a scrollframe so anchors work. That way you can scroll to 
       // anchors even if we don't have scrollbars.
 
       // create a style context for the scrollport of the viewport
-      nsCOMPtr<nsIStyleContext> scrollPseudoStyle;
-      aPresContext->ResolvePseudoStyleContextFor(nsnull,
-                                                nsCSSAnonBoxes::scrolledContent,
-                                                viewportPseudoStyle,
-                                                getter_AddRefs(scrollPseudoStyle));
+      nsRefPtr<nsStyleContext> scrollPseudoStyle;
+      scrollPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                     nsCSSAnonBoxes::scrolledContent,
+                                                                     viewportPseudoStyle);
 
       // create scrollframe
       nsIFrame* scrollFrame = nsnull;
@@ -3950,9 +3934,9 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
       scrollFrame->Init(aPresContext, nsnull, parentFrame, scrollPseudoStyle, nsnull);
 
       // resolve a new style for the root frame
-      aPresContext->ResolvePseudoStyleContextFor(nsnull, rootPseudo,
-                                                 scrollPseudoStyle,
-                                                 getter_AddRefs(rootPseudoStyle));
+      rootPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                   rootPseudo,
+                                                                   scrollPseudoStyle);
 
       // Inform the view manager about the root scrollable view
       nsIView* view = nsnull;
@@ -3995,7 +3979,7 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
     // Create the first page
     // Set the initial child lists
     nsIFrame *pageFrame, *pageContentFrame;
-    ConstructPageFrame(aPresShell, aPresContext, rootFrame, nsnull, 
+    ConstructPageFrame(aPresShell, aPresContext, rootFrame, nsnull,
                        pageFrame, pageContentFrame);
     rootFrame->SetInitialChildList(aPresContext, nsnull, pageFrame);
 
@@ -4014,7 +3998,7 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
 }
 
 NS_IMETHODIMP
-nsCSSFrameConstructor::ConstructPageFrame(nsIPresShell*   aPresShell, 
+nsCSSFrameConstructor::ConstructPageFrame(nsIPresShell*   aPresShell,
                                           nsIPresContext* aPresContext,
                                           nsIFrame*       aParentFrame,
                                           nsIFrame*       aPrevPageFrame,
@@ -4026,13 +4010,12 @@ nsCSSFrameConstructor::ConstructPageFrame(nsIPresShell*   aPresShell,
   if (NS_FAILED(rv))
     return rv;
 
-  nsCOMPtr<nsIStyleContext> parentStyleContext;
-  aParentFrame->GetStyleContext(getter_AddRefs(parentStyleContext));
+  nsStyleContext* parentStyleContext = aParentFrame->GetStyleContext();
 
-  nsCOMPtr<nsIStyleContext> pagePseudoStyle;
-  aPresContext->ResolvePseudoStyleContextFor(nsnull, nsCSSAnonBoxes::page,
-                                             parentStyleContext,
-                                             getter_AddRefs(pagePseudoStyle));
+  nsRefPtr<nsStyleContext> pagePseudoStyle;
+  pagePseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                               nsCSSAnonBoxes::page,
+                                                               parentStyleContext);
   // Initialize the page frame and force it to have a view. This makes printing of
   // the pages easier and faster.
   aPageFrame->Init(aPresContext, nsnull, aParentFrame, pagePseudoStyle, aPrevPageFrame);
@@ -4043,10 +4026,10 @@ nsCSSFrameConstructor::ConstructPageFrame(nsIPresShell*   aPresShell,
 
   NS_NewPageContentFrame(aPresShell, &aPageContentFrame);
 
-  nsCOMPtr<nsIStyleContext> pageContentPseudoStyle;
-  aPresContext->ResolvePseudoStyleContextFor(nsnull, nsCSSAnonBoxes::pageContent,
-                                             pagePseudoStyle,
-                                             getter_AddRefs(pageContentPseudoStyle));
+  nsRefPtr<nsStyleContext> pageContentPseudoStyle;
+  pageContentPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                      nsCSSAnonBoxes::pageContent,
+                                                                      pagePseudoStyle);
   // Initialize the page content frame and force it to have a view. Also make it the
   // containing block for fixed elements which are repeated on every page.
   aPageContentFrame->Init(aPresContext, nsnull, aPageFrame, pageContentPseudoStyle, nsnull);
@@ -4098,7 +4081,7 @@ nsCSSFrameConstructor::CreatePlaceholderFrameFor(nsIPresShell*    aPresShell,
                                                  nsIFrameManager* aFrameManager,
                                                  nsIContent*      aContent,
                                                  nsIFrame*        aFrame,
-                                                 nsIStyleContext* aStyleContext,
+                                                 nsStyleContext*  aStyleContext,
                                                  nsIFrame*        aParentFrame,
                                                  nsIFrame**       aPlaceholderFrame)
 {
@@ -4107,10 +4090,9 @@ nsCSSFrameConstructor::CreatePlaceholderFrameFor(nsIPresShell*    aPresShell,
 
   if (NS_SUCCEEDED(rv)) {
     // The placeholder frame gets a pseudo style context
-    nsCOMPtr<nsIStyleContext>  placeholderStyle;
-    nsCOMPtr<nsIStyleContext> parentContext = aStyleContext->GetParent();
-    aPresContext->ResolveStyleContextForNonElement(parentContext,
-                                             getter_AddRefs(placeholderStyle));
+    nsRefPtr<nsStyleContext> placeholderStyle;
+    nsStyleContext* parentContext = aStyleContext->GetParent();
+    placeholderStyle = aPresContext->ResolveStyleContextForNonElement(parentContext);
     placeholderFrame->Init(aPresContext, aContent, aParentFrame,
                            placeholderStyle, nsnull);
   
@@ -4183,7 +4165,7 @@ nsCSSFrameConstructor::ConstructRadioControlFrame(nsIPresShell*        aPresShel
                                                  nsIPresContext*  aPresContext,
                                                  nsIFrame*&   aNewFrame,
                                                  nsIContent*  aContent,
-                                                 nsIStyleContext* aStyleContext)
+                                                 nsStyleContext* aStyleContext)
 {
   nsresult rv = NS_OK;
 	if (GetFormElementRenderingMode(aPresContext, eWidgetType_Radio) == eWidgetRendering_Gfx)
@@ -4196,11 +4178,10 @@ nsCSSFrameConstructor::ConstructRadioControlFrame(nsIPresShell*        aPresShel
     return rv;
   }
 
-  nsCOMPtr<nsIStyleContext> radioStyle;
-  aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                             nsCSSAnonBoxes::radio,
-                                             aStyleContext,
-                                             getter_AddRefs(radioStyle));
+  nsRefPtr<nsStyleContext> radioStyle;
+  radioStyle = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                          nsCSSAnonBoxes::radio,
+                                                          aStyleContext);
   nsIRadioControlFrame* radio = nsnull;
   if (aNewFrame != nsnull && NS_SUCCEEDED(aNewFrame->QueryInterface(NS_GET_IID(nsIRadioControlFrame), (void**)&radio))) {
     radio->SetRadioButtonFaceStyleContext(radioStyle);
@@ -4214,7 +4195,7 @@ nsCSSFrameConstructor::ConstructCheckboxControlFrame(nsIPresShell*    aPresShell
                                                      nsIPresContext*  aPresContext,
                                                      nsIFrame*&       aNewFrame,
                                                      nsIContent*      aContent,
-                                                     nsIStyleContext* aStyleContext)
+                                                     nsStyleContext*  aStyleContext)
 {
   nsresult rv = NS_OK;
 	if (GetFormElementRenderingMode(aPresContext, eWidgetType_Checkbox) == eWidgetRendering_Gfx)
@@ -4227,9 +4208,10 @@ nsCSSFrameConstructor::ConstructCheckboxControlFrame(nsIPresShell*    aPresShell
     aNewFrame = nsnull;
   }
 
-  nsCOMPtr<nsIStyleContext> checkboxStyle;
-  aPresContext->ResolvePseudoStyleContextFor(aContent, nsCSSAnonBoxes::check, 
-                                             aStyleContext, getter_AddRefs(checkboxStyle));
+  nsRefPtr<nsStyleContext> checkboxStyle;
+  checkboxStyle = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                             nsCSSAnonBoxes::check, 
+                                                             aStyleContext);
   nsICheckboxControlFrame* checkbox = nsnull;
   if (aNewFrame != nsnull && 
       NS_SUCCEEDED(aNewFrame->QueryInterface(NS_GET_IID(nsICheckboxControlFrame), (void**)&checkbox))) {
@@ -4329,7 +4311,7 @@ nsCSSFrameConstructor::ConstructSelectFrame(nsIPresShell*        aPresShell,
                                             nsIContent*              aContent,
                                             nsIFrame*                aParentFrame,
                                             nsIAtom*                 aTag,
-                                            nsIStyleContext*         aStyleContext,
+                                            nsStyleContext*          aStyleContext,
                                             nsIFrame*&               aNewFrame,
                                             PRBool&                  aProcessChildren,
                                             PRBool                   aIsAbsolutelyPositioned,
@@ -4399,11 +4381,10 @@ nsCSSFrameConstructor::ConstructSelectFrame(nsIPresShell*        aPresShell,
       comboBox->SetDropDown(listFrame);
 
         // Resolve psuedo element style for the dropdown list 
-      nsCOMPtr<nsIStyleContext> listStyle;
-      rv = aPresContext->ResolvePseudoStyleContextFor(aContent, 
-                                              nsCSSAnonBoxes::dropDownList, 
-                                              aStyleContext,
-                                              getter_AddRefs(listStyle));
+      nsRefPtr<nsStyleContext> listStyle;
+      listStyle = aPresContext->ResolvePseudoStyleContextFor(aContent, 
+                                                             nsCSSAnonBoxes::dropDownList, 
+                                                             aStyleContext);
 
       // Initialize the scroll frame positioned. Note that it is NOT
       // initialized as absolutely positioned.
@@ -4511,7 +4492,7 @@ nsCSSFrameConstructor::InitializeSelectFrame(nsIPresShell*        aPresShell,
                                              nsIFrame*                scrolledFrame,
                                              nsIContent*              aContent,
                                              nsIFrame*                aParentFrame,
-                                             nsIStyleContext*         aStyleContext,
+                                             nsStyleContext*          aStyleContext,
                                              PRBool                   aIsAbsolutelyPositioned,
                                              PRBool                   aIsFixedPositioned,
                                              PRBool                   aCreateBlock)
@@ -4525,81 +4506,79 @@ nsCSSFrameConstructor::InitializeSelectFrame(nsIPresShell*        aPresShell,
     geometricParent = aState.mFixedItems.containingBlock;
   }
   
-  nsCOMPtr<nsIStyleContext> scrollPseudoStyle;
-  nsCOMPtr<nsIStyleContext> scrolledPseudoStyle;
+  nsRefPtr<nsStyleContext> scrolledPseudoStyle;
 
   
-    aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                  nsCSSAnonBoxes::scrolledContent,
-                                  aStyleContext,
-                                  getter_AddRefs(scrolledPseudoStyle));
+  scrolledPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                                   nsCSSAnonBoxes::scrolledContent,
+                                                                   aStyleContext);
 
-    InitAndRestoreFrame(aPresContext, aState, aContent, 
-                        geometricParent, aStyleContext, nsnull, scrollFrame);
+  InitAndRestoreFrame(aPresContext, aState, aContent, 
+                      geometricParent, aStyleContext, nsnull, scrollFrame);
 
-    // Initialize the frame and force it to have a view
-    // the scrolled frame is anonymous and does not have a content node
-    InitAndRestoreFrame(aPresContext, aState, aContent, 
-                        scrollFrame, scrolledPseudoStyle, nsnull, scrolledFrame);
+  // Initialize the frame and force it to have a view
+  // the scrolled frame is anonymous and does not have a content node
+  InitAndRestoreFrame(aPresContext, aState, aContent, 
+                      scrollFrame, scrolledPseudoStyle, nsnull, scrolledFrame);
 
-    nsHTMLContainerFrame::CreateViewForFrame(aPresContext, scrolledFrame,
+  nsHTMLContainerFrame::CreateViewForFrame(aPresContext, scrolledFrame,
                                            scrolledPseudoStyle, nsnull, PR_TRUE);
 
 
-    // The area frame is a floater container
-    PRBool haveFirstLetterStyle, haveFirstLineStyle;
-    HaveSpecialBlockStyle(aPresContext, aContent, aStyleContext,
-                          &haveFirstLetterStyle, &haveFirstLineStyle);
-    nsFrameConstructorSaveState floaterSaveState;
-    aState.PushFloaterContainingBlock(scrolledFrame, floaterSaveState,
-                                      haveFirstLetterStyle,
-                                      haveFirstLineStyle);
+  // The area frame is a floater container
+  PRBool haveFirstLetterStyle, haveFirstLineStyle;
+  HaveSpecialBlockStyle(aPresContext, aContent, aStyleContext,
+                        &haveFirstLetterStyle, &haveFirstLineStyle);
+  nsFrameConstructorSaveState floaterSaveState;
+  aState.PushFloaterContainingBlock(scrolledFrame, floaterSaveState,
+                                    haveFirstLetterStyle,
+                                    haveFirstLineStyle);
 
-    // Process children
-    nsFrameConstructorSaveState absoluteSaveState;
-    nsFrameItems                childItems;
-    PRBool                      isPositionedContainingBlock = aIsAbsolutelyPositioned ||
-                                                              aIsFixedPositioned;
+  // Process children
+  nsFrameConstructorSaveState absoluteSaveState;
+  nsFrameItems                childItems;
+  PRBool                      isPositionedContainingBlock = aIsAbsolutelyPositioned ||
+    aIsFixedPositioned;
 
-    if (isPositionedContainingBlock) {
-      // The area frame becomes a container for child frames that are
-      // absolutely positioned
-      aState.PushAbsoluteContainingBlock(aPresContext, scrolledFrame, absoluteSaveState);
-    }
-     
-    ProcessChildren(aPresShell, aPresContext, aState, aContent, scrolledFrame, PR_FALSE,
-                    childItems, PR_TRUE);
+  if (isPositionedContainingBlock) {
+    // The area frame becomes a container for child frames that are
+    // absolutely positioned
+    aState.PushAbsoluteContainingBlock(aPresContext, scrolledFrame, absoluteSaveState);
+  }
 
-    // if a select is being created with zero options we need to create
-    // a special pseudo frame so it can be sized as best it can
-    nsCOMPtr<nsIDOMHTMLSelectElement> selectElement;
-    nsresult result = aContent->QueryInterface(NS_GET_IID(nsIDOMHTMLSelectElement),
-                                                 (void**)getter_AddRefs(selectElement));
-    if (NS_SUCCEEDED(result) && selectElement) {
-      AddDummyFrameToSelect(aPresContext, aPresShell, aState,
-                            scrollFrame, scrolledFrame, &childItems,
-                            aContent, selectElement);
-    }
-    //////////////////////////////////////////////////
-    //////////////////////////////////////////////////
-    
-    // Set the scrolled frame's initial child lists
-    scrolledFrame->SetInitialChildList(aPresContext, nsnull, childItems.childList);
-    if (isPositionedContainingBlock && aState.mAbsoluteItems.childList) {
-      scrolledFrame->SetInitialChildList(aPresContext,
-                                         nsLayoutAtoms::absoluteList,
-                                         aState.mAbsoluteItems.childList);
-    }
+  ProcessChildren(aPresShell, aPresContext, aState, aContent, scrolledFrame, PR_FALSE,
+                  childItems, PR_TRUE);
 
-    if (aState.mFloatedItems.childList) {
-      scrolledFrame->SetInitialChildList(aPresContext,
-                                         nsLayoutAtoms::floaterList,
-                                         aState.mFloatedItems.childList);
-    }
+  // if a select is being created with zero options we need to create
+  // a special pseudo frame so it can be sized as best it can
+  nsCOMPtr<nsIDOMHTMLSelectElement> selectElement;
+  nsresult result = aContent->QueryInterface(NS_GET_IID(nsIDOMHTMLSelectElement),
+                                             (void**)getter_AddRefs(selectElement));
+  if (NS_SUCCEEDED(result) && selectElement) {
+    AddDummyFrameToSelect(aPresContext, aPresShell, aState,
+                          scrollFrame, scrolledFrame, &childItems,
+                          aContent, selectElement);
+  }
+  //////////////////////////////////////////////////
+  //////////////////////////////////////////////////
+
+  // Set the scrolled frame's initial child lists
+  scrolledFrame->SetInitialChildList(aPresContext, nsnull, childItems.childList);
+  if (isPositionedContainingBlock && aState.mAbsoluteItems.childList) {
+    scrolledFrame->SetInitialChildList(aPresContext,
+                                       nsLayoutAtoms::absoluteList,
+                                       aState.mAbsoluteItems.childList);
+  }
+
+  if (aState.mFloatedItems.childList) {
+    scrolledFrame->SetInitialChildList(aPresContext,
+                                       nsLayoutAtoms::floaterList,
+                                       aState.mFloatedItems.childList);
+  }
 
   // Set the scroll frame's initial child list
   scrollFrame->SetInitialChildList(aPresContext, nsnull, scrolledFrame);
-                                            
+
   return NS_OK;
 }
 
@@ -4615,7 +4594,7 @@ nsCSSFrameConstructor::ConstructFieldSetFrame(nsIPresShell*            aPresShel
                                               nsIContent*              aContent,
                                               nsIFrame*                aParentFrame,
                                               nsIAtom*                 aTag,
-                                              nsIStyleContext*         aStyleContext,
+                                              nsStyleContext*          aStyleContext,
                                               nsIFrame*&               aNewFrame,
                                               PRBool&                  aProcessChildren,
                                               PRBool                   aIsAbsolutelyPositioned,
@@ -4656,81 +4635,81 @@ nsCSSFrameConstructor::ConstructFieldSetFrame(nsIPresShell*            aPresShel
   NS_NewAreaFrame(shell, &areaFrame, NS_BLOCK_SPACE_MGR | NS_BLOCK_SHRINK_WRAP);
 
   // Resolve style and initialize the frame
-  nsIStyleContext* styleContext;
-  aPresContext->ResolvePseudoStyleContextFor(aContent, nsCSSAnonBoxes::fieldsetContent,
-                                             aStyleContext, &styleContext);
+  nsRefPtr<nsStyleContext> styleContext;
+  styleContext = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                            nsCSSAnonBoxes::fieldsetContent,
+                                                            aStyleContext);
   InitAndRestoreFrame(aPresContext, aState, aContent, 
                       newFrame, styleContext, nsnull, areaFrame);
 
-  NS_RELEASE(styleContext);          
   
 
-    // The area frame is a floater container
-    PRBool haveFirstLetterStyle, haveFirstLineStyle;
-    HaveSpecialBlockStyle(aPresContext, aContent, aStyleContext,
-                          &haveFirstLetterStyle, &haveFirstLineStyle);
-    nsFrameConstructorSaveState floaterSaveState;
-    aState.PushFloaterContainingBlock(areaFrame, floaterSaveState,
-                                      haveFirstLetterStyle,
-                                      haveFirstLineStyle);
+  // The area frame is a floater container
+  PRBool haveFirstLetterStyle, haveFirstLineStyle;
+  HaveSpecialBlockStyle(aPresContext, aContent, aStyleContext,
+                        &haveFirstLetterStyle, &haveFirstLineStyle);
+  nsFrameConstructorSaveState floaterSaveState;
+  aState.PushFloaterContainingBlock(areaFrame, floaterSaveState,
+                                    haveFirstLetterStyle,
+                                    haveFirstLineStyle);
 
-    // Process children
-    nsFrameConstructorSaveState absoluteSaveState;
-    nsFrameItems                childItems;
-    PRBool                      isPositionedContainingBlock = aIsAbsolutelyPositioned ||
-                                                              aIsFixedPositioned;
+  // Process children
+  nsFrameConstructorSaveState absoluteSaveState;
+  nsFrameItems                childItems;
+  PRBool                      isPositionedContainingBlock = aIsAbsolutelyPositioned ||
+    aIsFixedPositioned;
 
-    if (isPositionedContainingBlock) {
-      // The area frame becomes a container for child frames that are
-      // absolutely positioned
-      aState.PushAbsoluteContainingBlock(aPresContext, areaFrame, absoluteSaveState);
-    }
-     
-    ProcessChildren(aPresShell, aPresContext, aState, aContent, areaFrame, PR_FALSE,
-                    childItems, PR_TRUE);
+  if (isPositionedContainingBlock) {
+    // The area frame becomes a container for child frames that are
+    // absolutely positioned
+    aState.PushAbsoluteContainingBlock(aPresContext, areaFrame, absoluteSaveState);
+  }
 
-    static NS_DEFINE_IID(kLegendFrameCID, NS_LEGEND_FRAME_CID);
-    nsIFrame * child      = childItems.childList;
-    nsIFrame * previous   = nsnull;
-    nsIFrame* legendFrame = nsnull;
-    while (nsnull != child) {
-      nsresult result = child->QueryInterface(kLegendFrameCID, (void**)&legendFrame);
-      if (NS_SUCCEEDED(result) && legendFrame) {
-        if (nsnull != previous) {
-          nsIFrame * nxt;
-          legendFrame->GetNextSibling(&nxt);
-          previous->SetNextSibling(nxt);
-          areaFrame->SetNextSibling(legendFrame);
-          legendFrame->SetParent(newFrame);
-          legendFrame->SetNextSibling(nsnull);
-          break;
-        } else {
-          nsIFrame * nxt;
-          legendFrame->GetNextSibling(&nxt);
-          childItems.childList = nxt;
-          areaFrame->SetNextSibling(legendFrame);
-          legendFrame->SetParent(newFrame);
-          legendFrame->SetNextSibling(nsnull);
-          break;
-        }
+  ProcessChildren(aPresShell, aPresContext, aState, aContent, areaFrame, PR_FALSE,
+                  childItems, PR_TRUE);
+
+  static NS_DEFINE_IID(kLegendFrameCID, NS_LEGEND_FRAME_CID);
+  nsIFrame * child      = childItems.childList;
+  nsIFrame * previous   = nsnull;
+  nsIFrame* legendFrame = nsnull;
+  while (nsnull != child) {
+    nsresult result = child->QueryInterface(kLegendFrameCID, (void**)&legendFrame);
+    if (NS_SUCCEEDED(result) && legendFrame) {
+      if (nsnull != previous) {
+        nsIFrame * nxt;
+        legendFrame->GetNextSibling(&nxt);
+        previous->SetNextSibling(nxt);
+        areaFrame->SetNextSibling(legendFrame);
+        legendFrame->SetParent(newFrame);
+        legendFrame->SetNextSibling(nsnull);
+        break;
+      } else {
+        nsIFrame * nxt;
+        legendFrame->GetNextSibling(&nxt);
+        childItems.childList = nxt;
+        areaFrame->SetNextSibling(legendFrame);
+        legendFrame->SetParent(newFrame);
+        legendFrame->SetNextSibling(nsnull);
+        break;
       }
-      previous = child;
-      child->GetNextSibling(&child);
     }
+    previous = child;
+    child->GetNextSibling(&child);
+  }
 
-    // Set the scrolled frame's initial child lists
-    areaFrame->SetInitialChildList(aPresContext, nsnull, childItems.childList);
-    if (isPositionedContainingBlock && aState.mAbsoluteItems.childList) {
-      areaFrame->SetInitialChildList(aPresContext,
-                                         nsLayoutAtoms::absoluteList,
-                                         aState.mAbsoluteItems.childList);
-    }
+  // Set the scrolled frame's initial child lists
+  areaFrame->SetInitialChildList(aPresContext, nsnull, childItems.childList);
+  if (isPositionedContainingBlock && aState.mAbsoluteItems.childList) {
+    areaFrame->SetInitialChildList(aPresContext,
+                                   nsLayoutAtoms::absoluteList,
+                                   aState.mAbsoluteItems.childList);
+  }
 
-    if (aState.mFloatedItems.childList) {
-      areaFrame->SetInitialChildList(aPresContext,
-                                         nsLayoutAtoms::floaterList,
-                                         aState.mFloatedItems.childList);
-    }
+  if (aState.mFloatedItems.childList) {
+    areaFrame->SetInitialChildList(aPresContext,
+                                   nsLayoutAtoms::floaterList,
+                                   aState.mFloatedItems.childList);
+  }
 
   // Set the scroll frame's initial child list
   newFrame->SetInitialChildList(aPresContext, nsnull, areaFrame);
@@ -4750,7 +4729,7 @@ nsCSSFrameConstructor::ConstructTextFrame(nsIPresShell*            aPresShell,
                                           nsFrameConstructorState& aState,
                                           nsIContent*              aContent,
                                           nsIFrame*                aParentFrame,
-                                          nsIStyleContext*         aStyleContext,
+                                          nsStyleContext*          aStyleContext,
                                           nsFrameItems&            aFrameItems)
 {
   // process pending pseudo frames. whitespace doesn't have an effect.
@@ -4793,7 +4772,7 @@ nsCSSFrameConstructor::ConstructHTMLFrame(nsIPresShell*            aPresShell,
                                           nsIFrame*                aParentFrame,
                                           nsIAtom*                 aTag,
                                           PRInt32                  aNameSpaceID,
-                                          nsIStyleContext*         aStyleContext,
+                                          nsStyleContext*          aStyleContext,
                                           nsFrameItems&            aFrameItems)
 {
   // Ignore the tag if it's not HTML content
@@ -5404,7 +5383,7 @@ nsCSSFrameConstructor::ConstructXULFrame(nsIPresShell*            aPresShell,
                                          nsIFrame*                aParentFrame,
                                          nsIAtom*                 aTag,
                                          PRInt32                  aNameSpaceID,
-                                         nsIStyleContext*         aStyleContext,
+                                         nsStyleContext*          aStyleContext,
                                          nsFrameItems&            aFrameItems,
                                          PRBool                   aXBLBaseTag,
                                          PRBool&                  aHaltProcessing)
@@ -6041,18 +6020,17 @@ nsCSSFrameConstructor::ConstructXULFrame(nsIPresShell*            aPresShell,
 }
 #endif
 
-nsresult
+already_AddRefed<nsStyleContext>
 nsCSSFrameConstructor::BeginBuildingScrollFrame(nsIPresShell* aPresShell, 
                                                 nsIPresContext*         aPresContext,
                                                nsFrameConstructorState& aState,
                                                nsIContent*              aContent,
-                                               nsIStyleContext*         aContentStyle,
+                                               nsStyleContext*          aContentStyle,
                                                nsIFrame*                aParentFrame,
                                                nsIAtom*                 aScrolledPseudo,
                                                nsIDocument*             aDocument,
                                                PRBool                   aIsRoot,
                                                nsIFrame*&               aNewFrame,                                                                                             
-                                               nsCOMPtr<nsIStyleContext>& aScrolledChildStyle,
                                                nsIFrame*&               aScrollableFrame,
                                                nsIFrame*                aScrollPortFrame)
 {
@@ -6078,7 +6056,7 @@ nsCSSFrameConstructor::BeginBuildingScrollFrame(nsIPresShell* aPresShell,
 
   nsFrameItems anonymousItems;
 
-  nsCOMPtr<nsIStyleContext> contentStyle = dont_QueryInterface(aContentStyle);
+  nsRefPtr<nsStyleContext> contentStyle = aContentStyle;
 
   PRBool isGfx = HasGfxScrollbars();
 
@@ -6092,11 +6070,10 @@ nsCSSFrameConstructor::BeginBuildingScrollFrame(nsIPresShell* aPresShell,
     aNewFrame = gfxScrollFrame;
 
     // we used the style that was passed in. So resolve another one.
-    nsCOMPtr<nsIStyleContext> scrollPseudoStyle;
-    aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                              nsCSSAnonBoxes::scrolledContent,
-                                              contentStyle,
-                                              getter_AddRefs(scrollPseudoStyle));
+    nsRefPtr<nsStyleContext> scrollPseudoStyle;
+    scrollPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                                   nsCSSAnonBoxes::scrolledContent,
+                                                                   contentStyle);
 
     contentStyle = scrollPseudoStyle;
     InitAndRestoreFrame(aPresContext, aState, aContent, 
@@ -6110,13 +6087,9 @@ nsCSSFrameConstructor::BeginBuildingScrollFrame(nsIPresShell* aPresShell,
                         parentFrame, contentStyle, nsnull, scrollFrame);
   }
 
-  // initialize the scrolled frame
-  nsCOMPtr<nsIStyleContext> scrolledPseudoStyle;
-  aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                          aScrolledPseudo,
-                                          contentStyle,
-                                          getter_AddRefs(scrolledPseudoStyle));
-
+  nsStyleContext* aScrolledChildStyle = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                                                   aScrolledPseudo,
+                                                                                   contentStyle).get();
 
   aScrollableFrame = scrollFrame;
   
@@ -6127,13 +6100,11 @@ nsCSSFrameConstructor::BeginBuildingScrollFrame(nsIPresShell* aPresShell,
   }
 
 
-  aScrolledChildStyle = scrolledPseudoStyle;
-
   if (printPreviewContext && noScalingOfTwips) {
     printPreviewContext->SetScalingOfTwips(PR_TRUE);
   }
 
-  return NS_OK;
+  return aScrolledChildStyle;;
 }
 
 nsresult
@@ -6142,7 +6113,7 @@ nsCSSFrameConstructor::FinishBuildingScrollFrame(nsIPresContext*      aPresConte
                                              nsIContent*              aContent,
                                              nsIFrame*                aScrollFrame,
                                              nsIFrame*                aScrolledFrame,
-                                             nsIStyleContext*         aScrolledContentStyle)
+                                             nsStyleContext*          aScrolledContentStyle)
                                              
 {
   // create a view
@@ -6213,11 +6184,11 @@ nsCSSFrameConstructor::BuildScrollFrame       (nsIPresShell* aPresShell,
                                                nsIPresContext*          aPresContext,
                                                nsFrameConstructorState& aState,
                                                nsIContent*              aContent,
-                                               nsIStyleContext*         aContentStyle,
+                                               nsStyleContext*          aContentStyle,
                                                nsIFrame*                aScrolledFrame,
                                                nsIFrame*                aParentFrame,
                                                nsIFrame*&               aNewFrame, 
-                                               nsIStyleContext*&        aScrolledContentStyle,
+                                               nsStyleContext*&         aScrolledContentStyle,
                                                nsIFrame*                aScrollPortFrame)                                                                                                                                          
 {
     // Check to see the type of parent frame so we know whether we need to 
@@ -6238,21 +6209,20 @@ nsCSSFrameConstructor::BuildScrollFrame       (nsIPresShell* aPresShell,
 
     nsIFrame *scrollFrame;
 
-    nsCOMPtr<nsIStyleContext> scrolledContentStyle;
+    nsRefPtr<nsStyleContext> scrolledContentStyle;
 
     
-    BeginBuildingScrollFrame(aPresShell, aPresContext,
-                     aState,
-                     aContent,
-                     aContentStyle,
-                     aParentFrame,
-                     nsCSSAnonBoxes::scrolledContent,
-                     mDocument,
-                     PR_FALSE,
-                     aNewFrame,
-                     scrolledContentStyle,
-                     scrollFrame,
-                     aScrollPortFrame);
+    scrolledContentStyle = BeginBuildingScrollFrame(aPresShell, aPresContext,
+                                                    aState,
+                                                    aContent,
+                                                    aContentStyle,
+                                                    aParentFrame,
+                                                    nsCSSAnonBoxes::scrolledContent,
+                                                    mDocument,
+                                                    PR_FALSE,
+                                                    aNewFrame,
+                                                    scrollFrame,
+                                                    aScrollPortFrame);
     
     InitAndRestoreFrame(aPresContext, aState, aContent, 
                         scrollFrame, scrolledContentStyle, nsnull, aScrolledFrame);
@@ -6287,7 +6257,7 @@ nsCSSFrameConstructor::BuildGfxScrollFrame (nsIPresShell* aPresShell,
                                              nsIContent*              aContent,
                                              nsIDocument*             aDocument,
                                              nsIFrame*                aParentFrame,
-                                             nsIStyleContext*         aStyleContext,
+                                             nsStyleContext*          aStyleContext,
                                              PRBool                   aIsRoot,
                                              nsIFrame*&               aNewFrame,
                                              nsFrameItems&            aAnonymousFrames,
@@ -6327,7 +6297,7 @@ nsCSSFrameConstructor::ConstructFrameByDisplayType(nsIPresShell*            aPre
                                                    PRInt32                  aNameSpaceID,
                                                    nsIAtom*                 aTag,
                                                    nsIFrame*                aParentFrame,
-                                                   nsIStyleContext*         aStyleContext,
+                                                   nsStyleContext*          aStyleContext,
                                                    nsFrameItems&            aFrameItems)
 {
   PRBool    primaryFrameSet = PR_FALSE;
@@ -6405,7 +6375,7 @@ nsCSSFrameConstructor::ConstructFrameByDisplayType(nsIPresShell*            aPre
                     NS_BLOCK_SHRINK_WRAP | NS_BLOCK_MARGIN_ROOT);
 
 
-    nsIStyleContext* newStyle = nsnull;
+    nsStyleContext* newStyle;
     // Build the scrollframe it
     BuildScrollFrame(aPresShell, aPresContext, aState, aContent, aStyleContext, scrolledFrame, geometricParent,
                      newFrame, newStyle);
@@ -6444,7 +6414,7 @@ nsCSSFrameConstructor::ConstructFrameByDisplayType(nsIPresShell*            aPre
     CreateAnonymousFrames(aPresShell, aPresContext, tag, aState, aContent, newFrame,
                             childItems);
 
-      // Set the scrolled frame's initial child lists
+    // Set the scrolled frame's initial child lists
     scrolledFrame->SetInitialChildList(aPresContext, nsnull, childItems.childList);
     if (isPositionedContainingBlock && aState.mAbsoluteItems.childList) {
       scrolledFrame->SetInitialChildList(aPresContext,
@@ -6847,7 +6817,7 @@ nsCSSFrameConstructor::InitAndRestoreFrame(nsIPresContext*          aPresContext
                                            nsFrameConstructorState& aState,
                                            nsIContent*              aContent,
                                            nsIFrame*                aParentFrame,
-                                           nsIStyleContext*         aStyleContext,
+                                           nsStyleContext*          aStyleContext,
                                            nsIFrame*                aPrevInFlow,
                                            nsIFrame*                aNewFrame)
 {
@@ -6870,21 +6840,16 @@ nsCSSFrameConstructor::InitAndRestoreFrame(nsIPresContext*          aPresContext
   return rv;
 }
 
-nsresult
+already_AddRefed<nsStyleContext>
 nsCSSFrameConstructor::ResolveStyleContext(nsIPresContext*   aPresContext,
                                            nsIFrame*         aParentFrame,
-                                           nsIContent*       aContent,
-                                           nsIStyleContext** aStyleContext)
+                                           nsIContent*       aContent)
 {
-  nsresult rv = NS_OK;
   // Resolve the style context based on the content object and the parent
   // style context
-  nsCOMPtr<nsIStyleContext> parentStyleContext;
-
-  aParentFrame->GetStyleContext(getter_AddRefs(parentStyleContext));
+  nsStyleContext* parentStyleContext = aParentFrame->GetStyleContext();
   if (aContent->IsContentOfType(nsIContent::eELEMENT)) {
-    rv = aPresContext->ResolveStyleContextFor(aContent, parentStyleContext,
-                                              aStyleContext);
+    return aPresContext->ResolveStyleContextFor(aContent, parentStyleContext);
   } else {
 #ifdef DEBUG
     {
@@ -6895,10 +6860,8 @@ nsCSSFrameConstructor::ResolveStyleContext(nsIPresContext*   aPresContext,
                    "comments and processing instructions");
     }
 #endif
-    rv = aPresContext->ResolveStyleContextForNonElement(parentStyleContext,
-                                                        aStyleContext);
+    return aPresContext->ResolveStyleContextForNonElement(parentStyleContext);
   }
-  return rv;
 }
 
 // MathML Mod - RBS
@@ -6911,7 +6874,7 @@ nsCSSFrameConstructor::ConstructMathMLFrame(nsIPresShell*            aPresShell,
                                             nsIFrame*                aParentFrame,
                                             nsIAtom*                 aTag,
                                             PRInt32                  aNameSpaceID,
-                                            nsIStyleContext*         aStyleContext,
+                                            nsStyleContext*          aStyleContext,
                                             nsFrameItems&            aFrameItems)
 {
   // Make sure that we remain confined in the MathML world
@@ -6951,104 +6914,101 @@ nsCSSFrameConstructor::ConstructMathMLFrame(nsIPresShell*            aPresShell,
       aTag == nsMathMLAtoms::mn_ ||
       aTag == nsMathMLAtoms::ms_ ||
       aTag == nsMathMLAtoms::mtext_)
-     rv = NS_NewMathMLTokenFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLTokenFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mo_)
-     rv = NS_NewMathMLmoFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmoFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mfrac_)
-     rv = NS_NewMathMLmfracFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmfracFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::msup_)
-     rv = NS_NewMathMLmsupFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmsupFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::msub_)
-     rv = NS_NewMathMLmsubFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmsubFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::msubsup_)
-     rv = NS_NewMathMLmsubsupFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmsubsupFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::munder_)
-     rv = NS_NewMathMLmunderFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmunderFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mover_)
-     rv = NS_NewMathMLmoverFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmoverFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::munderover_)
-     rv = NS_NewMathMLmunderoverFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmunderoverFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mphantom_)
-     rv = NS_NewMathMLmphantomFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmphantomFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mpadded_)
-     rv = NS_NewMathMLmpaddedFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmpaddedFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mspace_)
-     rv = NS_NewMathMLmspaceFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmspaceFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mfenced_)
-     rv = NS_NewMathMLmfencedFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmfencedFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mmultiscripts_)
-     rv = NS_NewMathMLmmultiscriptsFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmmultiscriptsFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mstyle_)
-     rv = NS_NewMathMLmstyleFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmstyleFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::msqrt_)
-     rv = NS_NewMathMLmsqrtFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmsqrtFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mroot_)
-     rv = NS_NewMathMLmrootFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmrootFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::maction_)
-     rv = NS_NewMathMLmactionFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmactionFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mrow_   ||
            aTag == nsMathMLAtoms::merror_ ||
            aTag == nsMathMLAtoms::none_   ||
            aTag == nsMathMLAtoms::mprescripts_ )
-     rv = NS_NewMathMLmrowFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmrowFrame(aPresShell, &newFrame);
   // CONSTRUCTION of MTABLE elements
   else if (aTag == nsMathMLAtoms::mtable_ &&
            disp->mDisplay == NS_STYLE_DISPLAY_TABLE) {
-      // <mtable> is an inline-table -- but this isn't yet supported.
-      // What we do here is to wrap the table in an anonymous containing
-      // block so that it can mix better with other surrounding MathML markups
+    // <mtable> is an inline-table -- but this isn't yet supported.
+    // What we do here is to wrap the table in an anonymous containing
+    // block so that it can mix better with other surrounding MathML markups
 
-      nsCOMPtr<nsIStyleContext> parentContext;
-      aParentFrame->GetStyleContext(getter_AddRefs(parentContext));
+    nsStyleContext* parentContext = aParentFrame->GetStyleContext();
 
-      // first, create a MathML mrow frame that will wrap the block frame
-      rv = NS_NewMathMLmrowFrame(aPresShell, &newFrame);
-      if (NS_FAILED(rv)) return rv;
-      nsCOMPtr<nsIStyleContext> mrowContext;
-      aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                                 nsMathMLAtoms::mozMathInline,
-                                                 parentContext,
-                                                 getter_AddRefs(mrowContext));
-      InitAndRestoreFrame(aPresContext, aState, aContent, aParentFrame,
-                          mrowContext, nsnull, newFrame);
+    // first, create a MathML mrow frame that will wrap the block frame
+    rv = NS_NewMathMLmrowFrame(aPresShell, &newFrame);
+    if (NS_FAILED(rv)) return rv;
+    nsRefPtr<nsStyleContext> mrowContext;
+    mrowContext = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                             nsMathMLAtoms::mozMathInline,
+                                                             parentContext);
+    InitAndRestoreFrame(aPresContext, aState, aContent, aParentFrame,
+                        mrowContext, nsnull, newFrame);
 
-      // then, create a block frame that will wrap the table frame
-      nsIFrame* blockFrame;
-      rv = NS_NewBlockFrame(aPresShell, &blockFrame);
-      if (NS_FAILED(rv)) return rv;
-      nsCOMPtr<nsIStyleContext> blockContext;
-      aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                                 nsCSSAnonBoxes::mozAnonymousBlock,
-                                                 mrowContext,
-                                                 getter_AddRefs(blockContext));
-      InitAndRestoreFrame(aPresContext, aState, aContent, newFrame,
-                          blockContext, nsnull, blockFrame);
+    // then, create a block frame that will wrap the table frame
+    nsIFrame* blockFrame;
+    rv = NS_NewBlockFrame(aPresShell, &blockFrame);
+    if (NS_FAILED(rv)) return rv;
+    nsRefPtr<nsStyleContext> blockContext;
+    blockContext = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                              nsCSSAnonBoxes::mozAnonymousBlock,
+                                                              mrowContext);
+    InitAndRestoreFrame(aPresContext, aState, aContent, newFrame,
+                        blockContext, nsnull, blockFrame);
 
-      // then, create the table frame itself
-      nsCOMPtr<nsIStyleContext> tableContext;
-      aPresContext->ResolveStyleContextFor(aContent, blockContext,
-                                           getter_AddRefs(tableContext));
-      nsFrameItems tempItems;
-      nsIFrame* outerTable;
-      nsIFrame* innerTable;
-      PRBool pseudoParent;
-      nsMathMLmtableCreator mathTableCreator(aPresShell);
-      rv = ConstructTableFrame(aPresShell, aPresContext, aState, aContent, 
-                               blockFrame, tableContext, mathTableCreator,
-                               PR_FALSE, tempItems, outerTable, innerTable, pseudoParent);
-      // Note: table construction function takes care of initializing the frame,
-      // processing children, and setting the initial child list
+    // then, create the table frame itself
+    nsRefPtr<nsStyleContext> tableContext;
+    tableContext = aPresContext->ResolveStyleContextFor(aContent,
+                                                        blockContext);
+    nsFrameItems tempItems;
+    nsIFrame* outerTable;
+    nsIFrame* innerTable;
+    PRBool pseudoParent;
+    nsMathMLmtableCreator mathTableCreator(aPresShell);
+    rv = ConstructTableFrame(aPresShell, aPresContext, aState, aContent, 
+                             blockFrame, tableContext, mathTableCreator,
+                             PR_FALSE, tempItems, outerTable, innerTable, pseudoParent);
+    // Note: table construction function takes care of initializing the frame,
+    // processing children, and setting the initial child list
 
-      // set the outerTable as the initial child of the anonymous block
-      blockFrame->SetInitialChildList(aPresContext, nsnull, outerTable);
+    // set the outerTable as the initial child of the anonymous block
+    blockFrame->SetInitialChildList(aPresContext, nsnull, outerTable);
 
-      // set the block frame as the initial child of the mrow frame
-      newFrame->SetInitialChildList(aPresContext, nsnull, blockFrame);
+    // set the block frame as the initial child of the mrow frame
+    newFrame->SetInitialChildList(aPresContext, nsnull, blockFrame);
 
-      // add the new frame to the flow
-      aFrameItems.AddChild(newFrame);
+    // add the new frame to the flow
+    aFrameItems.AddChild(newFrame);
 
-      return rv; 
+    return rv; 
   }
   // End CONSTRUCTION of MTABLE elements 
 
@@ -7060,7 +7020,7 @@ nsCSSFrameConstructor::ConstructMathMLFrame(nsIPresShell*            aPresShell,
     rv = NS_NewMathMLmathFrame(aPresShell, &newFrame, isBlock);
   }
   else {
-     return rv;
+    return rv;
   }
 
   // If we succeeded in creating a frame then initialize it, process its
@@ -7137,7 +7097,7 @@ nsCSSFrameConstructor::ConstructSVGFrame(nsIPresShell*            aPresShell,
                                           nsIFrame*                aParentFrame,
                                           nsIAtom*                 aTag,
                                           PRInt32                  aNameSpaceID,
-                                          nsIStyleContext*         aStyleContext,
+                                          nsStyleContext*          aStyleContext,
                                           nsFrameItems&            aFrameItems)
 {
   NS_ASSERTION(NS_SUCCEEDED(aContent->GetNameSpaceID(aNameSpaceID)) && 
@@ -7273,7 +7233,7 @@ nsCSSFrameConstructor::PageBreakBefore(nsIPresShell*            aPresShell,
                                        nsFrameConstructorState& aState,
                                        nsIContent*              aContent,
                                        nsIFrame*                aParentFrame,
-                                       nsIStyleContext*         aStyleContext,
+                                       nsStyleContext*          aStyleContext,
                                        nsFrameItems&            aFrameItems)
 {
   const nsStyleDisplay* display = (const nsStyleDisplay*)
@@ -7298,14 +7258,13 @@ nsCSSFrameConstructor::ConstructPageBreakFrame(nsIPresShell*            aPresShe
                                                nsFrameConstructorState& aState,
                                                nsIContent*              aContent,
                                                nsIFrame*                aParentFrame,
-                                               nsIStyleContext*         aStyleContext,
+                                               nsStyleContext*          aStyleContext,
                                                nsFrameItems&            aFrameItems)
 {
-  nsCOMPtr<nsIStyleContext> pseudoStyle;
-  aPresContext->ResolvePseudoStyleContextFor(nsnull,
-                                             nsCSSAnonBoxes::pageBreak,
-                                             aStyleContext,
-                                             getter_AddRefs(pseudoStyle));
+  nsRefPtr<nsStyleContext> pseudoStyle;
+  pseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                           nsCSSAnonBoxes::pageBreak,
+                                                           aStyleContext);
   nsIFrame* pageBreakFrame;
   nsresult rv = NS_NewPageBreakFrame(aPresShell, &pageBreakFrame); 
   if (NS_SUCCEEDED(rv)) {
@@ -7343,31 +7302,28 @@ nsCSSFrameConstructor::ConstructFrame(nsIPresShell*            aPresShell,
       tag == nsLayoutAtoms::processingInstructionTagName)
     return rv;
 
-  nsCOMPtr<nsIStyleContext> styleContext;
-  rv = ResolveStyleContext(aPresContext, aParentFrame, aContent,
-                           getter_AddRefs(styleContext));
+  nsRefPtr<nsStyleContext> styleContext;
+  styleContext = ResolveStyleContext(aPresContext, aParentFrame, aContent);
 
-  if (NS_SUCCEEDED(rv)) {   
-    PRInt32 nameSpaceID;
-    aContent->GetNameSpaceID(nameSpaceID);
+  PRInt32 nameSpaceID;
+  aContent->GetNameSpaceID(nameSpaceID);
 
-    PRBool pageBreakAfter = PR_FALSE;
-    PRBool paginated;
-    aPresContext->IsPaginated(&paginated);
+  PRBool pageBreakAfter = PR_FALSE;
+  PRBool paginated;
+  aPresContext->IsPaginated(&paginated);
 
-    if (paginated) {
-      // See if there is a page break before, if so construct one. Also see if there is one after
-      pageBreakAfter = PageBreakBefore(aPresShell, aPresContext, aState, aContent, 
-                                       aParentFrame, styleContext, aFrameItems);
-    }
-    // construct the frame
-    rv = ConstructFrameInternal(aPresShell, aPresContext, aState, aContent, aParentFrame,
-                                tag, nameSpaceID, styleContext, aFrameItems, PR_FALSE);
-    if (NS_SUCCEEDED(rv) && pageBreakAfter) {
-      // Construct the page break after
-      ConstructPageBreakFrame(aPresShell, aPresContext, aState, aContent,
-                              aParentFrame, styleContext, aFrameItems);
-    }
+  if (paginated) {
+    // See if there is a page break before, if so construct one. Also see if there is one after
+    pageBreakAfter = PageBreakBefore(aPresShell, aPresContext, aState, aContent, 
+                                     aParentFrame, styleContext, aFrameItems);
+  }
+  // construct the frame
+  rv = ConstructFrameInternal(aPresShell, aPresContext, aState, aContent, aParentFrame,
+                              tag, nameSpaceID, styleContext, aFrameItems, PR_FALSE);
+  if (NS_SUCCEEDED(rv) && pageBreakAfter) {
+    // Construct the page break after
+    ConstructPageBreakFrame(aPresShell, aPresContext, aState, aContent,
+                            aParentFrame, styleContext, aFrameItems);
   }
   
   return rv;
@@ -7382,7 +7338,7 @@ nsCSSFrameConstructor::ConstructFrameInternal( nsIPresShell*            aPresShe
                                                nsIFrame*                aParentFrame,
                                                nsIAtom*                 aTag,
                                                PRInt32                  aNameSpaceID,
-                                               nsIStyleContext*         aStyleContext,
+                                               nsStyleContext*          aStyleContext,
                                                nsFrameItems&            aFrameItems,
                                                PRBool                   aXBLBaseTag)
 {
@@ -7391,7 +7347,7 @@ nsCSSFrameConstructor::ConstructFrameInternal( nsIPresShell*            aPresShe
   // can then be extended arbitrarily.
   const nsStyleDisplay*  display = (const nsStyleDisplay*)
         aStyleContext->GetStyleData(eStyleStruct_Display);
-  nsCOMPtr<nsIStyleContext> styleContext(aStyleContext);
+  nsRefPtr<nsStyleContext> styleContext(aStyleContext);
   nsCOMPtr<nsIXBLBinding> binding;
   if (!aXBLBaseTag)
   {
@@ -7409,10 +7365,8 @@ nsCSSFrameConstructor::ConstructFrameInternal( nsIPresShell*            aPresShe
         return NS_OK;
 
       if (resolveStyle) {
-        rv = ResolveStyleContext(aPresContext, aParentFrame, aContent,
-                                 getter_AddRefs(styleContext));
-        if (NS_FAILED(rv))
-          return rv;
+        styleContext = ResolveStyleContext(aPresContext, aParentFrame,
+                                           aContent);
       }
 
       nsCOMPtr<nsIAtom> baseTag;
@@ -7460,7 +7414,7 @@ nsCSSFrameConstructor::ConstructFrameInternal( nsIPresShell*            aPresShe
   // do it now, when constructing frames.  See bug 115291.
   {
     const nsStyleVisibility *vis;
-    GetStyleData(styleContext.get(), &vis);
+    GetStyleData(styleContext, &vis);
   }
 
   nsIFrame* lastChild = aFrameItems.lastChild;
@@ -7623,9 +7577,8 @@ nsCSSFrameConstructor::ReconstructDocElementHierarchy(nsIPresContext* aPresConte
             if (NS_SUCCEEDED(rv)) {
               // Create the new document element hierarchy
               nsIFrame*                 newChild;
-              nsCOMPtr<nsIStyleContext> rootPseudoStyle;
+              nsStyleContext* rootPseudoStyle = docParentFrame->GetStyleContext();
           
-              docParentFrame->GetStyleContext(getter_AddRefs(rootPseudoStyle));
               rv = ConstructDocElementFrame(shell, aPresContext, state, rootContent,
                                             docParentFrame, rootPseudoStyle,
                                             newChild);
@@ -7831,22 +7784,17 @@ IsGeneratedContentFor(nsIContent* aContent, nsIFrame* aFrame, nsIAtom* aPseudoEl
   // First check the frame state bit
   aFrame->GetFrameState(&state);
   if (state & NS_FRAME_GENERATED_CONTENT) {
-    nsIContent* content;
+    nsCOMPtr<nsIContent> content;
 
     // Check that it has the same content pointer
-    aFrame->GetContent(&content);
+    aFrame->GetContent(getter_AddRefs(content));
     if (content == aContent) {
-      nsIStyleContext* styleContext;
-      nsIAtom*         pseudoType;
+      nsStyleContext* styleContext = aFrame->GetStyleContext();
 
       // See if the pseudo element type matches
-      aFrame->GetStyleContext(&styleContext);
-      styleContext->GetPseudoType(pseudoType);
+      nsCOMPtr<nsIAtom> pseudoType = styleContext->GetPseudoType();
       result = (pseudoType == aPseudoElement);
-      NS_RELEASE(styleContext);
-      NS_IF_RELEASE(pseudoType);
     }
-    NS_IF_RELEASE(content);
   }
 
   return result;
@@ -8117,8 +8065,8 @@ nsCSSFrameConstructor::IsValidSibling(nsIPresShell&          aPresShell,
 
       nsIFrame* parent;
       aSibling.GetParent(&parent);
-      nsCOMPtr<nsIStyleContext> styleContext;
-      ResolveStyleContext(context, parent, &aContent, getter_AddRefs(styleContext));
+      nsRefPtr<nsStyleContext> styleContext;
+      styleContext = ResolveStyleContext(context, parent, &aContent);
       if (!styleContext) return PR_FALSE;
       const nsStyleDisplay* display = 
         (const nsStyleDisplay*) styleContext->GetStyleData(eStyleStruct_Display);
@@ -8534,8 +8482,8 @@ nsCSSFrameConstructor::ContentAppended(nsIPresContext* aPresContext,
       aContainer->ChildAt(aNewIndexInContainer, *getter_AddRefs(child));
       PRBool needReframe = !child;
       if (child && child->IsContentOfType(nsIContent::eELEMENT)) {
-        nsCOMPtr<nsIStyleContext> styleContext;
-        ResolveStyleContext(aPresContext, parentFrame, child, getter_AddRefs(styleContext)); 
+        nsRefPtr<nsStyleContext> styleContext;
+        styleContext = ResolveStyleContext(aPresContext, parentFrame, child);
         const nsStyleDisplay* display = 
           (const nsStyleDisplay*) styleContext->GetStyleData(eStyleStruct_Display);  
         // XXX since the block child goes in the last inline of the sacred triad, frames would 
@@ -8573,8 +8521,7 @@ nsCSSFrameConstructor::ContentAppended(nsIPresContext* aPresContext,
   PRBool haveFirstLetterStyle, haveFirstLineStyle;
   nsIFrame* containingBlock = state.mFloatedItems.containingBlock;
   nsCOMPtr<nsIContent> blockContent;
-  nsCOMPtr<nsIStyleContext> blockSC;
-  containingBlock->GetStyleContext(getter_AddRefs(blockSC));
+  nsStyleContext* blockSC = containingBlock->GetStyleContext();
   containingBlock->GetContent(getter_AddRefs(blockContent));
   HaveSpecialBlockStyle(aPresContext, blockContent, blockSC,
                         &haveFirstLetterStyle,
@@ -8789,9 +8736,8 @@ nsCSSFrameConstructor::AddDummyFrameToSelect(nsIPresContext*  aPresContext,
       listFrame->GetDummyFrame(&dummyFrame);
 
       if (!dummyFrame) {
-        nsCOMPtr<nsIStyleContext> styleContext;
+        nsStyleContext* styleContext = aParentFrame->GetStyleContext();
         nsIFrame*         generatedFrame = nsnull;
-        aParentFrame->GetStyleContext(getter_AddRefs(styleContext));
         if (CreateGeneratedContentFrame(aPresShell, aPresContext, aState,
                                         aParentFrame, aContainer,
                                         styleContext,
@@ -8894,8 +8840,8 @@ nsCSSFrameConstructor::NeedSpecialFrameReframe(nsIPresShell*   aPresShell,
   // find out if aChild is a block or inline
   PRBool childIsBlock = PR_FALSE;
   if (aChild->IsContentOfType(nsIContent::eELEMENT)) {
-    nsCOMPtr<nsIStyleContext> styleContext;
-    ResolveStyleContext(aPresContext, aParentFrame, aChild, getter_AddRefs(styleContext)); 
+    nsRefPtr<nsStyleContext> styleContext;
+    styleContext = ResolveStyleContext(aPresContext, aParentFrame, aChild);
     const nsStyleDisplay* display = 
       (const nsStyleDisplay*) styleContext->GetStyleData(eStyleStruct_Display);  
     childIsBlock = display->IsBlockLevel();
@@ -9060,8 +9006,7 @@ nsCSSFrameConstructor::ContentInserted(nsIPresContext*        aPresContext,
                       // InitialReflow.
 
       // Get the style context of the containing block frame
-      nsCOMPtr<nsIStyleContext> containerStyle;
-      mDocElementContainingBlock->GetStyleContext(getter_AddRefs(containerStyle));
+      nsStyleContext* containerStyle = mDocElementContainingBlock->GetStyleContext();
     
       // Create frames for the document element and its child elements
       nsIFrame*               docElementFrame;
@@ -9211,7 +9156,7 @@ nsCSSFrameConstructor::ContentInserted(nsIPresContext*        aPresContext,
   // is not the normal structure and requires custom updating
   // logic.
   nsIFrame* containingBlock = state.mFloatedItems.containingBlock;
-  nsCOMPtr<nsIStyleContext> blockSC;
+  nsStyleContext* blockSC;
   nsCOMPtr<nsIContent> blockContent;
   PRBool haveFirstLetterStyle = PR_FALSE;
   PRBool haveFirstLineStyle = PR_FALSE;
@@ -9232,7 +9177,7 @@ nsCSSFrameConstructor::ContentInserted(nsIPresContext*        aPresContext,
       (NS_STYLE_DISPLAY_INLINE == parentDisplay->mDisplay) ||
       (NS_STYLE_DISPLAY_INLINE_BLOCK == parentDisplay->mDisplay)) {
     // Recover the special style flags for the containing block
-    containingBlock->GetStyleContext(getter_AddRefs(blockSC));
+    blockSC = containingBlock->GetStyleContext();
     containingBlock->GetContent(getter_AddRefs(blockContent));
     HaveSpecialBlockStyle(aPresContext, blockContent, blockSC,
                           &haveFirstLetterStyle,
@@ -9663,15 +9608,14 @@ nsCSSFrameConstructor::RemoveMappingsForFrameSubtree(nsIPresContext* aPresContex
 static PRBool
 HasPseudoStyle(nsIPresContext* aPresContext,
                nsIContent* aContent,
-               nsIStyleContext* aStyleContext,
+               nsStyleContext* aStyleContext,
                nsIAtom* aPseudoElement)
 {
-  nsCOMPtr<nsIStyleContext> pseudoStyleContext;
+  nsRefPtr<nsStyleContext> pseudoStyleContext;
   if (aContent) {
-    aPresContext->ProbePseudoStyleContextFor(aContent,
-                                             aPseudoElement,
-                                             aStyleContext,
-                                             getter_AddRefs(pseudoStyleContext));
+    pseudoStyleContext = aPresContext->ProbePseudoStyleContextFor(aContent,
+                                                                  aPseudoElement,
+                                                                  aStyleContext);
   }
   return pseudoStyleContext != nsnull;
 }
@@ -9833,8 +9777,7 @@ nsCSSFrameConstructor::ContentRemoved(nsIPresContext* aPresContext,
     // :first-letter style applies.
     nsIFrame* containingBlock =
       GetFloaterContainingBlock(aPresContext, parentFrame);
-    nsCOMPtr<nsIStyleContext> blockSC;
-    containingBlock->GetStyleContext(getter_AddRefs(blockSC));
+    nsStyleContext* blockSC = containingBlock->GetStyleContext();
     nsCOMPtr<nsIContent> blockContent;
     containingBlock->GetContent(getter_AddRefs(blockContent));
     PRBool haveFLS = HaveFirstLetterStyle(aPresContext, blockContent, blockSC);
@@ -10322,8 +10265,7 @@ nsCSSFrameConstructor::ContentChanged(nsIPresContext* aPresContext,
         // See if the block has first-letter style applied to it.
         nsCOMPtr<nsIContent> blockContent;
         block->GetContent(getter_AddRefs(blockContent));
-        nsCOMPtr<nsIStyleContext> blockSC;
-        block->GetStyleContext(getter_AddRefs(blockSC));
+        nsStyleContext* blockSC = block->GetStyleContext();
         PRBool haveFirstLetterStyle =
           HaveFirstLetterStyle(aPresContext, blockContent, blockSC);
         if (haveFirstLetterStyle) {
@@ -10701,7 +10643,7 @@ nsCSSFrameConstructor::AttributeChanged(nsIPresContext* aPresContext,
   // check for inline style.  we need to clear the data at the style
   // context's rule node whenever the inline style property changes.
 
-  nsCOMPtr<nsIStyleContext> styleContext;
+  nsStyleContext* styleContext;
   nsCOMPtr<nsIStyleRule> rule;
   PRBool inlineStyle = PR_FALSE;
   if (aAttribute == nsHTMLAtoms::style) {
@@ -10712,13 +10654,14 @@ nsCSSFrameConstructor::AttributeChanged(nsIPresContext* aPresContext,
 
       // This style rule exists and we need to blow away any computed
       // data that this rule cached in the rule tree.
-      if (primaryStyleFrame)
-        primaryStyleFrame->GetStyleContext(getter_AddRefs(styleContext));
-      else {
+      if (primaryStyleFrame) {
+        styleContext = primaryStyleFrame->GetStyleContext();
+        styleContext->AddRef();
+      } else {
         // We might be in the undisplayed map.  Retrieve the style context from there.
         nsCOMPtr<nsIFrameManager> frameManager;
         shell->GetFrameManager(getter_AddRefs(frameManager));
-        frameManager->GetUndisplayedContent(aContent, getter_AddRefs(styleContext));
+        styleContext = frameManager->GetUndisplayedContent(aContent);
 #ifdef DEBUG
         if (!styleContext) {
           nsCOMPtr<nsIContent> parent;
@@ -10733,6 +10676,8 @@ nsCSSFrameConstructor::AttributeChanged(nsIPresContext* aPresContext,
 #endif
       }
     }
+    if (styleContext)
+      styleContext->Release();
   }
 
   // first see if we need to manage the style system: 
@@ -10937,7 +10882,7 @@ nsresult
 nsCSSFrameConstructor::ConstructAlternateFrame(nsIPresShell*    aPresShell, 
                                                nsIPresContext*  aPresContext,
                                                nsIContent*      aContent,
-                                               nsIStyleContext* aStyleContext,
+                                               nsStyleContext*  aStyleContext,
                                                nsIFrame*        aParentFrame,
                                                nsIFrame*&       aFrame)
 {
@@ -10997,15 +10942,13 @@ nsCSSFrameConstructor::ConstructAlternateFrame(nsIPresShell*    aPresShell,
   // Create a text frame to display the alt-text. It gets a pseudo-element
   // style context
   nsIFrame*        textFrame;
-  nsIStyleContext* textStyleContext;
-
   NS_NewTextFrame(aPresShell, &textFrame);
-  aPresContext->ResolveStyleContextForNonElement(aStyleContext,
-                                                 &textStyleContext);
+
+  nsRefPtr<nsStyleContext> textStyleContext;
+  textStyleContext = aPresContext->ResolveStyleContextForNonElement(aStyleContext);
 
   textFrame->Init(aPresContext, altTextContent, containerFrame,
                   textStyleContext, nsnull);
-  NS_RELEASE(textStyleContext);
   containerFrame->SetInitialChildList(aPresContext, nsnull, textFrame);
 
   // Return the container frame
@@ -11086,9 +11029,8 @@ nsCSSFrameConstructor::CantRenderReplacedElement(nsIPresShell* aPresShell,
 
   // Get parent frame and style context
   nsIFrame*                 parentFrame;
-  nsCOMPtr<nsIStyleContext> styleContext;
   aFrame->GetParent(&parentFrame);
-  aFrame->GetStyleContext(getter_AddRefs(styleContext));
+  nsStyleContext* styleContext = aFrame->GetStyleContext();
 
   // Get aFrame's content object and the tag name
   nsCOMPtr<nsIContent>      content;
@@ -11338,7 +11280,7 @@ nsCSSFrameConstructor::CreateContinuingOuterTableFrame(nsIPresShell* aPresShell,
                                                        nsIFrame*        aFrame,
                                                        nsIFrame*        aParentFrame,
                                                        nsIContent*      aContent,
-                                                       nsIStyleContext* aStyleContext,
+                                                       nsStyleContext*  aStyleContext,
                                                        nsIFrame**       aContinuingFrame)
 {
   nsIFrame* newFrame;
@@ -11372,11 +11314,10 @@ nsCSSFrameConstructor::CreateContinuingOuterTableFrame(nsIPresShell* aPresShell,
         // the caption (that is what the thead is for). This code is not executed 
         // anyway, because the caption was put in a different child list.
         nsIContent*           caption;
-        nsIStyleContext*      captionStyle;
+        nsStyleContext*       captionStyle = childFrame->GetStyleContext();
         const nsStyleDisplay* display;
 
         childFrame->GetContent(&caption);
-        childFrame->GetStyleContext(&captionStyle);
         display = (const nsStyleDisplay*)captionStyle->GetStyleData(eStyleStruct_Display);
         NS_ASSERTION(NS_STYLE_DISPLAY_TABLE_CAPTION == display->mDisplay, "expected caption");
 
@@ -11402,7 +11343,6 @@ nsCSSFrameConstructor::CreateContinuingOuterTableFrame(nsIPresShell* aPresShell,
         }
         newChildFrames.AddChild(captionFrame);
         NS_RELEASE(caption);
-        NS_RELEASE(captionStyle);
       }
       NS_IF_RELEASE(tableType);
       childFrame->GetNextSibling(&childFrame);
@@ -11422,7 +11362,7 @@ nsCSSFrameConstructor::CreateContinuingTableFrame(nsIPresShell* aPresShell,
                                                   nsIFrame*        aFrame,
                                                   nsIFrame*        aParentFrame,
                                                   nsIContent*      aContent,
-                                                  nsIStyleContext* aStyleContext,
+                                                  nsStyleContext*  aStyleContext,
                                                   nsIFrame**       aContinuingFrame)
 {
   nsIFrame* newFrame;
@@ -11441,10 +11381,9 @@ nsCSSFrameConstructor::CreateContinuingTableFrame(nsIPresShell* aPresShell,
     aFrame->FirstChild(aPresContext, nsnull, &rowGroupFrame);
     while (rowGroupFrame) {
       // See if it's a header/footer
-      nsIStyleContext*      rowGroupStyle;
+      nsStyleContext*       rowGroupStyle = rowGroupFrame->GetStyleContext();
       const nsStyleDisplay* display;
 
-      rowGroupFrame->GetStyleContext(&rowGroupStyle);
       display = (const nsStyleDisplay*)rowGroupStyle->GetStyleData(eStyleStruct_Display);
 
       if ((NS_STYLE_DISPLAY_TABLE_HEADER_GROUP == display->mDisplay) ||
@@ -11485,8 +11424,6 @@ nsCSSFrameConstructor::CreateContinuingTableFrame(nsIPresShell* aPresShell,
         }
       }
 
-      NS_RELEASE(rowGroupStyle);
-      
       // Get the next row group frame
       rowGroupFrame->GetNextSibling(&rowGroupFrame);
     }
@@ -11508,14 +11445,13 @@ nsCSSFrameConstructor::CreateContinuingFrame(nsIPresShell*   aPresShell,
 {
   nsCOMPtr<nsIAtom>          frameType;
   nsCOMPtr<nsIContent>       content;
-  nsCOMPtr<nsIStyleContext>  styleContext;
+  nsStyleContext*            styleContext = aFrame->GetStyleContext();
   nsIFrame*                  newFrame = nsnull;
   nsresult                   rv = NS_OK;
 
   // Use the frame type to determine what type of frame to create
   aFrame->GetFrameType(getter_AddRefs(frameType));
   aFrame->GetContent(getter_AddRefs(content));
-  aFrame->GetStyleContext(getter_AddRefs(styleContext));
 
   if (nsLayoutAtoms::textFrame == frameType) {
     rv = NS_NewContinuingTextFrame(aPresShell, &newFrame);
@@ -11560,7 +11496,7 @@ nsCSSFrameConstructor::CreateContinuingFrame(nsIPresShell*   aPresShell,
 
   } else if (nsLayoutAtoms::pageFrame == frameType) {
     nsIFrame* pageContentFrame;
-    rv = ConstructPageFrame(aPresShell, aPresContext, aParentFrame, aFrame, 
+    rv = ConstructPageFrame(aPresShell, aPresContext, aParentFrame, aFrame,
                             newFrame, pageContentFrame);
   } else if (nsLayoutAtoms::tableOuterFrame == frameType) {
     rv = CreateContinuingOuterTableFrame(aPresShell, aPresContext, aFrame, aParentFrame,
@@ -12095,7 +12031,7 @@ nsresult
 nsCSSFrameConstructor::RecreateFramesForContent(nsIPresContext* aPresContext,
                                                 nsIContent* aContent, PRBool aInlineStyle,
                                                 nsIStyleRule* aInlineStyleRule,
-                                                nsIStyleContext* aStyleContext)                                   
+                                                nsStyleContext* aStyleContext)                                   
 {
   // Is the frame `special'? If so, we need to reframe the containing
   // block *here*, rather than trying to remove and re-insert the
@@ -12186,32 +12122,30 @@ nsCSSFrameConstructor::RecreateFramesForContent(nsIPresContext* aPresContext,
 
 // Block frame construction code
 
-nsIStyleContext*
+already_AddRefed<nsStyleContext>
 nsCSSFrameConstructor::GetFirstLetterStyle(nsIPresContext* aPresContext,
                                            nsIContent* aContent,
-                                           nsIStyleContext* aStyleContext)
+                                           nsStyleContext* aStyleContext)
 {
-  nsIStyleContext* fls = nsnull;
   if (aContent) {
-    aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                               nsCSSPseudoElements::firstLetter,
-                                               aStyleContext, &fls);
+    return aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                      nsCSSPseudoElements::firstLetter,
+                                                      aStyleContext);
   }
-  return fls;
+  return nsnull;
 }
 
-nsIStyleContext*
+already_AddRefed<nsStyleContext>
 nsCSSFrameConstructor::GetFirstLineStyle(nsIPresContext* aPresContext,
                                          nsIContent* aContent,
-                                         nsIStyleContext* aStyleContext)
+                                         nsStyleContext* aStyleContext)
 {
-  nsIStyleContext* fls = nsnull;
   if (aContent) {
-    aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                               nsCSSPseudoElements::firstLine,
-                                               aStyleContext, &fls);
+    return aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                      nsCSSPseudoElements::firstLine,
+                                                      aStyleContext);
   }
-  return fls;
+  return nsnull;
 }
 
 // Predicate to see if a given content (block element) has
@@ -12219,7 +12153,7 @@ nsCSSFrameConstructor::GetFirstLineStyle(nsIPresContext* aPresContext,
 PRBool
 nsCSSFrameConstructor::HaveFirstLetterStyle(nsIPresContext* aPresContext,
                                             nsIContent* aContent,
-                                            nsIStyleContext* aStyleContext)
+                                            nsStyleContext* aStyleContext)
 {
   return HasPseudoStyle(aPresContext, aContent, aStyleContext,
                         nsCSSPseudoElements::firstLetter);
@@ -12228,7 +12162,7 @@ nsCSSFrameConstructor::HaveFirstLetterStyle(nsIPresContext* aPresContext,
 PRBool
 nsCSSFrameConstructor::HaveFirstLineStyle(nsIPresContext* aPresContext,
                                           nsIContent* aContent,
-                                          nsIStyleContext* aStyleContext)
+                                          nsStyleContext* aStyleContext)
 {
   return HasPseudoStyle(aPresContext, aContent, aStyleContext,
                         nsCSSPseudoElements::firstLine);
@@ -12237,7 +12171,7 @@ nsCSSFrameConstructor::HaveFirstLineStyle(nsIPresContext* aPresContext,
 void
 nsCSSFrameConstructor::HaveSpecialBlockStyle(nsIPresContext* aPresContext,
                                              nsIContent* aContent,
-                                             nsIStyleContext* aStyleContext,
+                                             nsStyleContext* aStyleContext,
                                              PRBool* aHaveFirstLetterStyle,
                                              PRBool* aHaveFirstLineStyle)
 {
@@ -12267,8 +12201,7 @@ nsCSSFrameConstructor::ProcessChildren(nsIPresShell*            aPresShell,
                                        nsTableCreator*          aTableCreator)
 {
   nsresult rv = NS_OK;
-  nsCOMPtr<nsIStyleContext> styleContext;
-  aFrame->GetStyleContext(getter_AddRefs(styleContext));
+  nsStyleContext* styleContext = aFrame->GetStyleContext();
     
   if (aCanHaveGeneratedContent) {
     // Probe for generated content before
@@ -12342,7 +12275,7 @@ nsCSSFrameConstructor::ProcessChildren(nsIPresShell*            aPresShell,
 static void
 ReparentFrame(nsIPresContext* aPresContext,
               nsIFrame* aNewParentFrame,
-              nsIStyleContext* aParentStyleContext,
+              nsStyleContext* aParentStyleContext,
               nsIFrame* aFrame)
 {
   aPresContext->ReParentStyleContext(aFrame, aParentStyleContext);
@@ -12384,9 +12317,8 @@ nsCSSFrameConstructor::WrapFramesInFirstLineFrame(
   }
 
   // Create line frame
-  nsCOMPtr<nsIStyleContext> parentStyle;
-  aFrame->GetStyleContext(getter_AddRefs(parentStyle));
-  nsCOMPtr<nsIStyleContext> firstLineStyle(
+  nsStyleContext* parentStyle = aFrame->GetStyleContext();
+  nsRefPtr<nsStyleContext> firstLineStyle(
     getter_AddRefs(GetFirstLineStyle(aPresContext, aContent, parentStyle))
     );
   nsIFrame* lineFrame;
@@ -12463,8 +12395,7 @@ nsCSSFrameConstructor::AppendFirstLineFrames(
     return rv;
   }
   nsIFrame* lineFrame = lastBlockKid;
-  nsCOMPtr<nsIStyleContext> firstLineStyle;
-  lineFrame->GetStyleContext(getter_AddRefs(firstLineStyle));
+  nsStyleContext* firstLineStyle = lineFrame->GetStyleContext();
 
   // Find the first and last inline frame in aFrameItems
   nsIFrame* kid = aFrameItems.childList;
@@ -12540,8 +12471,7 @@ nsCSSFrameConstructor::InsertFirstLineFrames(
     if (frameType.get() == nsLayoutAtoms::lineFrame) {
       // We already have a first-line frame
       nsIFrame* lineFrame = firstBlockKid;
-      nsCOMPtr<nsIStyleContext> firstLineStyle;
-      lineFrame->GetStyleContext(getter_AddRefs(firstLineStyle));
+      nsStyleContext* firstLineStyle = lineFrame->GetStyleContext();
 
       if (isInline) {
         // Easy case: the new inline frame will go into the lineFrame.
@@ -12569,9 +12499,8 @@ nsCSSFrameConstructor::InsertFirstLineFrames(
         rv = NS_NewFirstLineFrame(&lineFrame);
         if (NS_SUCCEEDED(rv)) {
           // Lookup first-line style context
-          nsCOMPtr<nsIStyleContext> parentStyle;
-          aBlockFrame->GetStyleContext(getter_AddRefs(parentStyle));
-          nsCOMPtr<nsIStyleContext> firstLineStyle(
+          nsStyleContext* parentStyle = aBlockFrame->GetStyleContext();
+          nsRefPtr<nsStyleContext> firstLineStyle(
             getter_AddRefs(GetFirstLineStyle(aPresContext, aContent,
                                              parentStyle))
             );
@@ -12758,7 +12687,7 @@ nsCSSFrameConstructor::CreateFloatingLetterFrame(
   nsIFrame* aTextFrame,
   nsIContent* aBlockContent,
   nsIFrame* aParentFrame,
-  nsIStyleContext* aStyleContext,
+  nsStyleContext* aStyleContext,
   nsFrameItems& aResult)
 {
   // Create the first-letter-frame
@@ -12772,9 +12701,8 @@ nsCSSFrameConstructor::CreateFloatingLetterFrame(
   // get a proper style context for it (the one passed in is for the
   // letter frame and will have the float property set on it; the text
   // frame shouldn't have that set).
-  nsCOMPtr<nsIStyleContext> textSC;
-  aPresContext->ResolveStyleContextForNonElement(aStyleContext,
-                                                 getter_AddRefs(textSC));  
+  nsRefPtr<nsStyleContext> textSC;
+  textSC = aPresContext->ResolveStyleContextForNonElement(aStyleContext);
   InitAndRestoreFrame(aPresContext, aState, aTextContent, 
                       letterFrame, textSC, nsnull, aTextFrame);
 
@@ -12798,12 +12726,10 @@ nsCSSFrameConstructor::CreateFloatingLetterFrame(
                           &nextTextFrame);
 
     // Repair the continuations style context
-    nsCOMPtr<nsIStyleContext> parentStyleContext;
-    parentStyleContext = getter_AddRefs(aStyleContext->GetParent());
+    nsStyleContext* parentStyleContext = aStyleContext->GetParent();
     if (parentStyleContext) {
-      nsCOMPtr<nsIStyleContext> newSC;
-      aPresContext->ResolveStyleContextForNonElement(parentStyleContext,
-                                                     getter_AddRefs(newSC));
+      nsRefPtr<nsStyleContext> newSC;
+      newSC = aPresContext->ResolveStyleContextForNonElement(parentStyleContext);
       if (newSC) {
         nextTextFrame->SetStyleContext(aPresContext, newSC);
       }
@@ -12836,8 +12762,7 @@ nsCSSFrameConstructor::CreateLetterFrame(nsIPresShell* aPresShell, nsIPresContex
   aParentFrame->GetContent(getter_AddRefs(parentContent));
 
   // Get style context for the first-letter-frame
-  nsCOMPtr<nsIStyleContext> parentStyleContext;
-  aParentFrame->GetStyleContext(getter_AddRefs(parentStyleContext));
+  nsStyleContext* parentStyleContext = aParentFrame->GetStyleContext();
   if (parentStyleContext) {
     // Use content from containing block so that we can actually
     // find a matching style rule.
@@ -12846,7 +12771,7 @@ nsCSSFrameConstructor::CreateLetterFrame(nsIPresShell* aPresShell, nsIPresContex
       getter_AddRefs(blockContent));
 
     // Create first-letter style rule
-    nsCOMPtr<nsIStyleContext> sc = getter_AddRefs(
+    nsRefPtr<nsStyleContext> sc = getter_AddRefs(
       GetFirstLetterStyle(aPresContext, blockContent, parentStyleContext));
     if (sc) {
       // Create a new text frame (the original one will be discarded)
@@ -12871,9 +12796,8 @@ nsCSSFrameConstructor::CreateLetterFrame(nsIPresShell* aPresShell, nsIPresContex
           // Initialize the first-letter-frame.
           letterFrame->Init(aPresContext, aTextContent, aParentFrame,
                             sc, nsnull);
-          nsCOMPtr<nsIStyleContext> textSC;
-          aPresContext->ResolveStyleContextForNonElement(sc,
-                                                       getter_AddRefs(textSC));
+          nsRefPtr<nsStyleContext> textSC;
+          textSC = aPresContext->ResolveStyleContextForNonElement(sc);
           InitAndRestoreFrame(aPresContext, aState, aTextContent, 
                               letterFrame, textSC, nsnull, textFrame);          
           letterFrame->SetInitialChildList(aPresContext, nsnull, textFrame);
@@ -13072,8 +12996,7 @@ nsCSSFrameConstructor::RemoveFloatingFirstLetterFrames(
   // Create a new text frame with the right style context that maps
   // all of the content that was previously part of the letter frame
   // (and probably continued elsewhere).
-  nsCOMPtr<nsIStyleContext> parentSC;
-  parentFrame->GetStyleContext(getter_AddRefs(parentSC));
+  nsStyleContext* parentSC = parentFrame->GetStyleContext();
   if (!parentSC) {
     return NS_OK;
   }
@@ -13082,9 +13005,8 @@ nsCSSFrameConstructor::RemoveFloatingFirstLetterFrames(
   if (!textContent) {
     return NS_OK;
   }
-  nsCOMPtr<nsIStyleContext> newSC;
-  aPresContext->ResolveStyleContextForNonElement(parentSC,
-                                                 getter_AddRefs(newSC));
+  nsRefPtr<nsStyleContext> newSC;
+  newSC = aPresContext->ResolveStyleContextForNonElement(parentSC);
   if (!newSC) {
     return NS_OK;
   }
@@ -13172,8 +13094,7 @@ nsCSSFrameConstructor::RemoveFirstLetterFrames(nsIPresContext* aPresContext,
       }
 
       // Create a new textframe
-      nsCOMPtr<nsIStyleContext> parentSC;
-      aFrame->GetStyleContext(getter_AddRefs(parentSC));
+      nsStyleContext* parentSC = aFrame->GetStyleContext();
       if (!parentSC) {
         break;
       }
@@ -13182,9 +13103,8 @@ nsCSSFrameConstructor::RemoveFirstLetterFrames(nsIPresContext* aPresContext,
       if (!textContent) {
         break;
       }
-      nsCOMPtr<nsIStyleContext> newSC;
-      aPresContext->ResolveStyleContextForNonElement(parentSC,
-                                                     getter_AddRefs(newSC));
+      nsRefPtr<nsStyleContext> newSC;
+      newSC = aPresContext->ResolveStyleContextForNonElement(parentSC);
       if (!newSC) {
         break;
       }
@@ -13307,20 +13227,17 @@ nsCSSFrameConstructor::CreateListBoxContent(nsIPresContext* aPresContext,
                                   GetFloaterContainingBlock(aPresContext, aParentFrame), 
                                   mTempFrameTreeState);
 
-    nsCOMPtr<nsIStyleContext> styleContext;
-    rv = ResolveStyleContext(aPresContext, aParentFrame, aChild,
-                             getter_AddRefs(styleContext));
+    nsRefPtr<nsStyleContext> styleContext;
+    styleContext = ResolveStyleContext(aPresContext, aParentFrame, aChild);
 
-    if (NS_SUCCEEDED(rv)) {
-      // Pre-check for display "none" - only if we find that, do we create
-      // any frame at all
-      const nsStyleDisplay* display = (const nsStyleDisplay*)
-        styleContext->GetStyleData(eStyleStruct_Display);
+    // Pre-check for display "none" - only if we find that, do we create
+    // any frame at all
+    const nsStyleDisplay* display = (const nsStyleDisplay*)
+      styleContext->GetStyleData(eStyleStruct_Display);
 
-      if (NS_STYLE_DISPLAY_NONE == display->mDisplay) {
-        *aNewFrame = nsnull;
-        return NS_OK;
-      }
+    if (NS_STYLE_DISPLAY_NONE == display->mDisplay) {
+      *aNewFrame = nsnull;
+      return NS_OK;
     }
 
     nsCOMPtr<nsIAtom> tag;
@@ -13392,7 +13309,7 @@ nsCSSFrameConstructor::ConstructBlock(nsIPresShell*            aPresShell,
                                       const nsStyleDisplay*    aDisplay,
                                       nsIContent*              aContent,
                                       nsIFrame*                aParentFrame,
-                                      nsIStyleContext*         aStyleContext,
+                                      nsStyleContext*          aStyleContext,
                                       nsIFrame*                aNewFrame,
                                       PRBool                   aRelPos)
 {
@@ -13468,12 +13385,12 @@ nsCSSFrameConstructor::ProcessBlockChildren(nsIPresShell* aPresShell,
                                             PRBool                   aParentIsBlock)
 {
   nsresult rv = NS_OK;
-  nsCOMPtr<nsIStyleContext> styleContext;
+  nsStyleContext* styleContext;
 
   if (aCanHaveGeneratedContent) {
     // Probe for generated content before
     nsIFrame* generatedFrame;
-    aFrame->GetStyleContext(getter_AddRefs(styleContext));
+    styleContext = aFrame->GetStyleContext();
     if (CreateGeneratedContentFrame(aPresShell, aPresContext, aState, aFrame, aContent,
                                     styleContext, nsCSSPseudoElements::before,
                                     nsnull, &generatedFrame)) {
@@ -13544,7 +13461,7 @@ nsCSSFrameConstructor::ConstructInline(nsIPresShell*            aPresShell,
                                        const nsStyleDisplay*    aDisplay,
                                        nsIContent*              aContent,
                                        nsIFrame*                aParentFrame,
-                                       nsIStyleContext*         aStyleContext,
+                                       nsStyleContext*          aStyleContext,
                                        PRBool                   aIsPositioned,
                                        nsIFrame*                aNewFrame,
                                        nsIFrame**               aNewBlockFrame,
@@ -13662,10 +13579,9 @@ nsCSSFrameConstructor::ConstructInline(nsIPresShell*            aPresShell,
     blockStyle = nsCSSAnonBoxes::mozAnonymousBlock;
   }
 
-  nsCOMPtr<nsIStyleContext> blockSC;
-  aPresContext->ResolvePseudoStyleContextFor(aContent, blockStyle,
-                                             aStyleContext,
-                                             getter_AddRefs(blockSC));
+  nsRefPtr<nsStyleContext> blockSC;
+  blockSC = aPresContext->ResolvePseudoStyleContextFor(aContent, blockStyle,
+                                                       aStyleContext);
 
   InitAndRestoreFrame(aPresContext, aState, aContent, 
                       aParentFrame, blockSC, nsnull, blockFrame);  
@@ -13768,7 +13684,7 @@ nsCSSFrameConstructor::ProcessInlineChildren(nsIPresShell* aPresShell,
                                              PRBool*                  aKidsAllInline)
 {
   nsresult rv = NS_OK;
-  nsCOMPtr<nsIStyleContext> styleContext;
+  nsStyleContext* styleContext;
 
   // save the pseudo frame state 
   nsPseudoFrames prevPseudoFrames; 
@@ -13777,7 +13693,7 @@ nsCSSFrameConstructor::ProcessInlineChildren(nsIPresShell* aPresShell,
   if (aCanHaveGeneratedContent) {
     // Probe for generated content before
     nsIFrame* generatedFrame;
-    aFrame->GetStyleContext(getter_AddRefs(styleContext));
+    styleContext = aFrame->GetStyleContext();
     if (CreateGeneratedContentFrame(aPresShell, aPresContext, aState, aFrame, aContent,
                                     styleContext, nsCSSPseudoElements::before,
                                     nsnull, &generatedFrame)) {
@@ -14107,8 +14023,7 @@ nsCSSFrameConstructor::SplitToContainingBlock(nsIPresContext* aPresContext,
 
       if (state & NS_FRAME_HAS_VIEW) {
         // ...create a new view for the block child, and reparent views
-        nsCOMPtr<nsIStyleContext> sc;
-        aLeftInlineChildFrame->GetStyleContext(getter_AddRefs(sc));
+        nsStyleContext* sc = aLeftInlineChildFrame->GetStyleContext();
 
         nsHTMLContainerFrame::CreateViewForFrame(aPresContext, aBlockChildFrame,
                                                  sc, nsnull, PR_FALSE);
@@ -14144,14 +14059,12 @@ nsCSSFrameConstructor::SplitToContainingBlock(nsIPresContext* aPresContext,
   if (! blockFrame)
     return NS_ERROR_OUT_OF_MEMORY;
 
-  nsCOMPtr<nsIStyleContext> styleContext;
-  aFrame->GetStyleContext(getter_AddRefs(styleContext));
+  nsStyleContext* styleContext = aFrame->GetStyleContext();
 
-  nsCOMPtr<nsIStyleContext> blockSC;
-  aPresContext->ResolvePseudoStyleContextFor(content,
-                                             nsCSSAnonBoxes::mozAnonymousBlock,
-                                             styleContext,
-                                             getter_AddRefs(blockSC));
+  nsRefPtr<nsStyleContext> blockSC;
+  blockSC = aPresContext->ResolvePseudoStyleContextFor(content,
+                                                       nsCSSAnonBoxes::mozAnonymousBlock,
+                                                       styleContext);
 
   InitAndRestoreFrame(aPresContext, aState, content,
                       nsnull, blockSC, nsnull, blockFrame);
diff --git a/mozilla/layout/base/nsCSSFrameConstructor.h b/mozilla/layout/base/nsCSSFrameConstructor.h
index a62d6aa2376..2a4642a5ffb 100644
--- a/mozilla/layout/base/nsCSSFrameConstructor.h
+++ b/mozilla/layout/base/nsCSSFrameConstructor.h
@@ -50,7 +50,7 @@ class nsIDocument;
 struct nsFrameItems;
 struct nsAbsoluteItems;
 struct nsTableCreator;
-class nsIStyleContext;
+class nsStyleContext;
 struct nsTableList;
 struct nsStyleContent;
 struct nsStyleDisplay;
@@ -204,14 +204,14 @@ protected:
                                 nsFrameConstructorState& aState,
                                 nsIContent*              aContent,
                                 nsIFrame*                aParentFrame,
-                                nsIStyleContext*         aStyleContext,
+                                nsStyleContext*          aStyleContext,
                                 nsIFrame*                aPrevInFlow,
                                 nsIFrame*                aNewFrame);
 
-  nsresult ResolveStyleContext(nsIPresContext*   aPresContext,
-                               nsIFrame*         aParentFrame,
-                               nsIContent*       aContent,
-                               nsIStyleContext** aStyleContext);
+  already_AddRefed<nsStyleContext>
+  ResolveStyleContext(nsIPresContext*   aPresContext,
+                      nsIFrame*         aParentFrame,
+                      nsIContent*       aContent);
 
   nsresult ConstructFrame(nsIPresShell*            aPresShell,
                           nsIPresContext*          aPresContext,
@@ -225,7 +225,7 @@ protected:
                                     nsFrameConstructorState& aState,
                                     nsIContent*              aDocElement,
                                     nsIFrame*                aParentFrame,
-                                    nsIStyleContext*         aParentStyleContext,
+                                    nsStyleContext*          aParentStyleContext,
                                     nsIFrame*&               aNewFrame);
 
   nsresult ConstructDocElementTableFrame(nsIPresShell*          aPresShell, 
@@ -239,7 +239,7 @@ protected:
                                    nsIDocument*          aDocument,
                                    nsIFrame*             aParentFrame,
                                    nsIContent*           aContent,
-                                   nsIStyleContext*      aStyleContext,
+                                   nsStyleContext*       aStyleContext,
                                    const nsStyleContent* aStyleContent,
                                    PRUint32              aContentIndex,
                                    nsIFrame**            aFrame);
@@ -249,7 +249,7 @@ protected:
                                      nsFrameConstructorState& aState,
                                      nsIFrame*                aFrame,
                                      nsIContent*              aContent,
-                                     nsIStyleContext*         aStyleContext,
+                                     nsStyleContext*          aStyleContext,
                                      nsIAtom*                 aPseudoElement,
                                      nsIFrame**               aWrapperFrame,
                                      nsIFrame**               aResult);
@@ -267,7 +267,7 @@ protected:
                                nsFrameConstructorState& aState,
                                nsIContent*              aContent,
                                nsIFrame*                aParent,
-                               nsIStyleContext*         aStyleContext,
+                               nsStyleContext*          aStyleContext,
                                nsTableCreator&          aTableCreator,
                                PRBool                   aIsPseudo,
                                nsFrameItems&            aChildItems,
@@ -280,7 +280,7 @@ protected:
                                       nsFrameConstructorState& aState,
                                       nsIContent*              aContent,
                                       nsIFrame*                aParent,
-                                      nsIStyleContext*         aStyleContext,
+                                      nsStyleContext*          aStyleContext,
                                       nsTableCreator&          aTableCreator,
                                       nsFrameItems&            aChildItems,
                                       nsIFrame*&               aNewFrame,
@@ -291,7 +291,7 @@ protected:
                                        nsFrameConstructorState& aState,
                                        nsIContent*              aContent,
                                        nsIFrame*                aParent,
-                                       nsIStyleContext*         aStyleContext,
+                                       nsStyleContext*          aStyleContext,
                                        nsTableCreator&          aTableCreator,
                                        PRBool                   aIsPseudo,
                                        nsFrameItems&            aChildItems,
@@ -303,7 +303,7 @@ protected:
                                        nsFrameConstructorState& aState,
                                        nsIContent*              aContent,
                                        nsIFrame*                aParent,
-                                       nsIStyleContext*         aStyleContext,
+                                       nsStyleContext*          aStyleContext,
                                        nsTableCreator&          aTableCreator,
                                        PRBool                   aIsPseudo,
                                        nsFrameItems&            aChildItems,
@@ -315,7 +315,7 @@ protected:
                                   nsFrameConstructorState& aState,
                                   nsIContent*              aContent,
                                   nsIFrame*                aParent,
-                                  nsIStyleContext*         aStyleContext,
+                                  nsStyleContext*          aStyleContext,
                                   nsTableCreator&          aTableCreator,
                                   PRBool                   aIsPseudo,
                                   nsFrameItems&            aChildItems,
@@ -327,7 +327,7 @@ protected:
                                   nsFrameConstructorState& aState,
                                   nsIContent*              aContent,
                                   nsIFrame*                aParent,
-                                  nsIStyleContext*         aStyleContext,
+                                  nsStyleContext*          aStyleContext,
                                   nsTableCreator&          aTableCreator,
                                   PRBool                   aIsPseudo,
                                   nsFrameItems&            aChildItems,
@@ -339,7 +339,7 @@ protected:
                                    nsFrameConstructorState& aState,
                                    nsIContent*              aContent,
                                    nsIFrame*                aParentFrame,
-                                   nsIStyleContext*         aStyleContext,
+                                   nsStyleContext*          aStyleContext,
                                    nsTableCreator&          aTableCreator,
                                    PRBool                   aIsPseudo,
                                    nsFrameItems&            aChildItems,
@@ -351,14 +351,14 @@ protected:
                                   nsIFrame*        aParentFrame,
                                   nsIAtom*         aTag,
                                   nsIContent*      aContent,
-                                  nsIStyleContext* aContext);
+                                  nsStyleContext*  aContext);
 
   nsresult ConstructTableForeignFrame(nsIPresShell*            aPresShell, 
                                       nsIPresContext*          aPresContext,
                                       nsFrameConstructorState& aState,
                                       nsIContent*              aContent,
                                       nsIFrame*                aParentFrameIn,
-                                      nsIStyleContext*         aStyleContext,
+                                      nsStyleContext*          aStyleContext,
                                       nsTableCreator&          aTableCreator,
                                       nsFrameItems&            aChildItems,
                                       nsIFrame*&               aNewFrame,
@@ -449,7 +449,7 @@ protected:
                              nsIContent*              aParentContent,
                              nsIFrame*                aParentFrame,
                              nsIAtom*                 aParentFrameType,
-                             nsIStyleContext*         aParentStyleContext,
+                             nsStyleContext*          aParentStyleContext,
                              nsTableCreator&          aTableCreator,
                              nsFrameItems&            aChildItems,
                              nsIFrame*&               aCaption);
@@ -463,14 +463,14 @@ protected:
                                      nsIFrameManager* aFrameManager,
                                      nsIContent*      aContent,
                                      nsIFrame*        aFrame,
-                                     nsIStyleContext* aStyleContext,
+                                     nsStyleContext*  aStyleContext,
                                      nsIFrame*        aParentFrame,
                                      nsIFrame**       aPlaceholderFrame);
 
   nsresult ConstructAlternateFrame(nsIPresShell*    aPresShell, 
                                    nsIPresContext*  aPresContext,
                                    nsIContent*      aContent,
-                                   nsIStyleContext* aStyleContext,
+                                   nsStyleContext*  aStyleContext,
                                    nsIFrame*        aParentFrame,
                                    nsIFrame*&       aFrame);
 
@@ -481,13 +481,13 @@ protected:
                                       nsIPresContext*    aPresContext,
                                       nsIFrame*&         aNewFrame,
                                       nsIContent*        aContent,
-                                      nsIStyleContext*   aStyleContext);
+                                      nsStyleContext*    aStyleContext);
 
   nsresult ConstructCheckboxControlFrame(nsIPresShell*    aPresShell, 
                                          nsIPresContext*  aPresContext,
                                          nsIFrame*&       aNewFrame,
                                          nsIContent*      aContent,
-                                         nsIStyleContext* aStyleContext);
+                                         nsStyleContext*  aStyleContext);
 
   nsresult ConstructButtonControlFrame(nsIPresShell*    aPresShell,
                                        nsIPresContext*  aPresContext,
@@ -505,7 +505,7 @@ protected:
                                 nsIContent*              aContent,
                                 nsIFrame*                aParentFrame,
                                 nsIAtom*                 aTag,
-                                nsIStyleContext*         aStyleContext,
+                                nsStyleContext*          aStyleContext,
                                 nsIFrame*&               aNewFrame,
                                 PRBool&                  aProcessChildren,
                                 PRBool                   aIsAbsolutelyPositioned,
@@ -519,7 +519,7 @@ protected:
                                   nsIContent*              aContent,
                                   nsIFrame*                aParentFrame,
                                   nsIAtom*                 aTag,
-                                  nsIStyleContext*         aStyleContext,
+                                  nsStyleContext*          aStyleContext,
                                   nsIFrame*&               aNewFrame,
                                   PRBool&                  aProcessChildren,
                                   PRBool                   aIsAbsolutelyPositioned,
@@ -531,7 +531,7 @@ protected:
                               nsFrameConstructorState& aState,
                               nsIContent*              aContent,
                               nsIFrame*                aParentFrame,
-                              nsIStyleContext*         aStyleContext,
+                              nsStyleContext*          aStyleContext,
                               nsFrameItems&            aFrameItems);
 
   nsresult ConstructPageBreakFrame(nsIPresShell*            aPresShell, 
@@ -539,7 +539,7 @@ protected:
                                    nsFrameConstructorState& aState,
                                    nsIContent*              aContent,
                                    nsIFrame*                aParentFrame,
-                                   nsIStyleContext*         aStyleContext,
+                                   nsStyleContext*          aStyleContext,
                                    nsFrameItems&            aFrameItems);
 
   // Construct a page break frame if page-break-before:always is set in aStyleContext
@@ -550,7 +550,7 @@ protected:
                          nsFrameConstructorState& aState,
                          nsIContent*              aContent,
                          nsIFrame*                aParentFrame,
-                         nsIStyleContext*         aStyleContext,
+                         nsStyleContext*          aStyleContext,
                          nsFrameItems&            aFrameItems);
 
   nsresult ConstructHTMLFrame(nsIPresShell*            aPresShell, 
@@ -560,7 +560,7 @@ protected:
                               nsIFrame*                aParentFrame,
                               nsIAtom*                 aTag,
                               PRInt32                  aNameSpaceID,
-                              nsIStyleContext*         aStyleContext,
+                              nsStyleContext*          aStyleContext,
                               nsFrameItems&            aFrameItems);
 
   nsresult ConstructFrameInternal( nsIPresShell*            aPresShell, 
@@ -570,7 +570,7 @@ protected:
                                    nsIFrame*                aParentFrame,
                                    nsIAtom*                 aTag,
                                    PRInt32                  aNameSpaceID,
-                                   nsIStyleContext*         aStyleContext,
+                                   nsStyleContext*          aStyleContext,
                                    nsFrameItems&            aFrameItems,
                                    PRBool                   aXBLBaseTag);
 
@@ -600,7 +600,7 @@ protected:
                                 nsIFrame*                aParentFrame,
                                 nsIAtom*                 aTag,
                                 PRInt32                  aNameSpaceID,
-                                nsIStyleContext*         aStyleContext,
+                                nsStyleContext*          aStyleContext,
                                 nsFrameItems&            aFrameItems);
 #endif
 
@@ -612,7 +612,7 @@ protected:
                              nsIFrame*                aParentFrame,
                              nsIAtom*                 aTag,
                              PRInt32                  aNameSpaceID,
-                             nsIStyleContext*         aStyleContext,
+                             nsStyleContext*          aStyleContext,
                              nsFrameItems&            aFrameItems,
                              PRBool                   aXBLBaseTag,
                              PRBool&                  aHaltProcessing);
@@ -628,7 +628,7 @@ protected:
                                 nsIFrame*                aParentFrame,
                                 nsIAtom*                 aTag,
                                 PRInt32                  aNameSpaceID,
-                                nsIStyleContext*         aStyleContext,
+                                nsStyleContext*          aStyleContext,
                                 nsFrameItems&            aFrameItems);
 #endif
 
@@ -640,7 +640,7 @@ protected:
                                        PRInt32                  aNameSpaceID,
                                        nsIAtom*                 aTag,
                                        nsIFrame*                aParentFrame,
-                                       nsIStyleContext*         aStyleContext,
+                                       nsStyleContext*          aStyleContext,
                                        nsFrameItems&            aFrameItems);
 
   nsresult ProcessChildren(nsIPresShell*            aPresShell, 
@@ -657,7 +657,7 @@ protected:
                             nsIPresContext*  aPresContext,
                             nsIContent*      aContent,
                             nsIFrame*&       aFrame,
-                            nsIStyleContext* aStyleContext);
+                            nsStyleContext*  aStyleContext);
 
   nsresult AddDummyFrameToSelect(nsIPresContext*          aPresContext,
                                  nsIPresShell*            aPresShell,
@@ -697,28 +697,27 @@ protected:
                    nsIPresContext*          aPresContext,
                    nsFrameConstructorState& aState,
                    nsIContent*              aContent,
-                   nsIStyleContext*         aContentStyle,
+                   nsStyleContext*          aContentStyle,
                    nsIFrame*                aScrolledFrame,
                    nsIFrame*                aParentFrame,
                    nsIFrame*&               aNewFrame,
-                   nsIStyleContext*&        aScrolledChildStyle,
+                   nsStyleContext*&         aScrolledChildStyle,
                    nsIFrame*                aScrollPort = nsnull);
 
   // Builds the initial ScrollFrame: 
   //  if Gfx scrollbasrs in ares, it creates a GfxScrollFrame, otherwise it creates a ScrollFrame
   //
-  nsresult
+  already_AddRefed<nsStyleContext>
   BeginBuildingScrollFrame(nsIPresShell*            aPresShell, 
                            nsIPresContext*          aPresContext,
                            nsFrameConstructorState& aState,
                            nsIContent*              aContent,
-                           nsIStyleContext*         aContentStyle,
+                           nsStyleContext*          aContentStyle,
                            nsIFrame*                aParentFrame,
                            nsIAtom*                 aScrolledPseudo,
                            nsIDocument*             aDocument,
                            PRBool                   aIsRoot,
                            nsIFrame*&               aNewFrame, 
-                           nsCOMPtr<nsIStyleContext>& aScrolledChildStyle,
                            nsIFrame*&               aScrollableFrame,
                            nsIFrame*                aScrollPort = nsnull);
 
@@ -731,7 +730,7 @@ protected:
                             nsIContent*              aContent,
                             nsIFrame*                aScrollFrame,
                             nsIFrame*                aScrolledFrame,
-                            nsIStyleContext*         scrolledPseudoStyle);
+                            nsStyleContext*          scrolledPseudoStyle);
 
   // Creates a new GfxScrollFrame, Initializes it, and creates a scroll port for it
   //
@@ -742,7 +741,7 @@ protected:
                       nsIContent*              aContent,
                       nsIDocument*             aDocument,
                       nsIFrame*                aParentFrame,
-                      nsIStyleContext*         aStyleContext,
+                      nsStyleContext*          aStyleContext,
                       PRBool                   aIsRoot,
                       nsIFrame*&               aNewFrame,
                       nsFrameItems&            aAnonymousFrames,
@@ -757,7 +756,7 @@ protected:
                         nsIFrame*                scrolledFrame,
                         nsIContent*              aContent,
                         nsIFrame*                aParentFrame,
-                        nsIStyleContext*         aStyleContext,
+                        nsStyleContext*          aStyleContext,
                         PRBool                   aIsAbsolutelyPositioned,
                         PRBool                   aIsFixedPositioned,
                         PRBool                   aCreateBlock);
@@ -771,7 +770,7 @@ protected:
                                     nsIContent*      aContent, 
                                     PRBool           aInlineStyle = PR_FALSE,
                                     nsIStyleRule*    aRule = nsnull,
-                                    nsIStyleContext* aContext = nsnull);
+                                    nsStyleContext*  aContext = nsnull);
 
   nsresult RecreateFramesOnAttributeChange(nsIPresContext* aPresContext,
                                            nsIContent*     aContent,
@@ -782,7 +781,7 @@ protected:
                                            nsIFrame*        aFrame,
                                            nsIFrame*        aParentFrame,
                                            nsIContent*      aContent,
-                                           nsIStyleContext* aStyleContext,
+                                           nsStyleContext*  aStyleContext,
                                            nsIFrame**       aContinuingFrame);
 
   nsresult CreateContinuingTableFrame(nsIPresShell*    aPresShell, 
@@ -790,32 +789,34 @@ protected:
                                       nsIFrame*        aFrame,
                                       nsIFrame*        aParentFrame,
                                       nsIContent*      aContent,
-                                      nsIStyleContext* aStyleContext,
+                                      nsStyleContext*  aStyleContext,
                                       nsIFrame**       aContinuingFrame);
 
   //----------------------------------------
 
   // Methods support creating block frames and their children
 
-  static nsIStyleContext* GetFirstLetterStyle(nsIPresContext*  aPresContext,
-                                              nsIContent*      aContent,
-                                              nsIStyleContext* aStyleContext);
+  static already_AddRefed<nsStyleContext>
+  GetFirstLetterStyle(nsIPresContext*  aPresContext,
+                      nsIContent*      aContent,
+                      nsStyleContext*  aStyleContext);
 
-  static nsIStyleContext* GetFirstLineStyle(nsIPresContext*  aPresContext,
-                                            nsIContent*      aContent,
-                                            nsIStyleContext* aStyleContext);
+  static already_AddRefed<nsStyleContext>
+  GetFirstLineStyle(nsIPresContext*  aPresContext,
+                    nsIContent*      aContent,
+                    nsStyleContext*  aStyleContext);
 
   static PRBool HaveFirstLetterStyle(nsIPresContext*  aPresContext,
                                      nsIContent*      aContent,
-                                     nsIStyleContext* aStyleContext);
+                                     nsStyleContext*  aStyleContext);
 
   static PRBool HaveFirstLineStyle(nsIPresContext*  aPresContext,
                                    nsIContent*      aContent,
-                                   nsIStyleContext* aStyleContext);
+                                   nsStyleContext*  aStyleContext);
 
   static void HaveSpecialBlockStyle(nsIPresContext*  aPresContext,
                                     nsIContent*      aContent,
-                                    nsIStyleContext* aStyleContext,
+                                    nsStyleContext*  aStyleContext,
                                     PRBool*          aHaveFirstLetterStyle,
                                     PRBool*          aHaveFirstLineStyle);
 
@@ -829,7 +830,7 @@ protected:
                           const nsStyleDisplay*    aDisplay,
                           nsIContent*              aContent,
                           nsIFrame*                aParentFrame,
-                          nsIStyleContext*         aStyleContext,
+                          nsStyleContext*          aStyleContext,
                           nsIFrame*                aNewFrame,
                           PRBool                   aRelPos);
 
@@ -848,7 +849,7 @@ protected:
                            const nsStyleDisplay*    aDisplay,
                            nsIContent*              aContent,
                            nsIFrame*                aParentFrame,
-                           nsIStyleContext*         aStyleContext,
+                           nsStyleContext*          aStyleContext,
                            PRBool                   aIsPositioned,
                            nsIFrame*                aNewFrame,
                            nsIFrame**               aNewBlockFrame,
@@ -925,7 +926,7 @@ protected:
                                  nsIFrame*                aTextFrame,
                                  nsIContent*              aBlockContent,
                                  nsIFrame*                aParentFrame,
-                                 nsIStyleContext*         aStyleContext,
+                                 nsStyleContext*          aStyleContext,
                                  nsFrameItems&            aResult);
 
   nsresult CreateLetterFrame(nsIPresShell*            aPresShell, 
diff --git a/mozilla/layout/base/nsCSSRendering.cpp b/mozilla/layout/base/nsCSSRendering.cpp
index 60d446d824e..cfb8d8bc5fd 100644
--- a/mozilla/layout/base/nsCSSRendering.cpp
+++ b/mozilla/layout/base/nsCSSRendering.cpp
@@ -43,7 +43,7 @@
 #include "nsRect.h"
 #include "nsIViewManager.h"
 #include "nsIPresShell.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIScrollableView.h"
 #include "nsLayoutAtoms.h"
 #include "nsIDrawingSurface.h"
@@ -1562,8 +1562,7 @@ PRBool GetBGColorForHTMLElement( nsIPresContext *aPresContext,
             // use this guy's color
             nsIFrame *pFrame = nsnull;
             if (NS_SUCCEEDED(shell->GetPrimaryFrameFor(pContent, &pFrame)) && pFrame) {
-              nsIStyleContext *pContext = nsnull;
-              pFrame->GetStyleContext(&pContext);
+              nsStyleContext *pContext = pFrame->GetStyleContext();
               if (pContext) {
                 const nsStyleBackground* color = (const nsStyleBackground*)pContext->GetStyleData(eStyleStruct_Background);
                 NS_ASSERTION(color,"ColorStyleData should not be null");
@@ -1572,7 +1571,6 @@ PRBool GetBGColorForHTMLElement( nsIPresContext *aPresContext,
                   // set the reslt to TRUE to indicate we mapped the color
                   result = PR_TRUE;
                 }
-                NS_RELEASE(pContext);
               }// if context
             }// if frame
           }// if tag == html or body
@@ -1672,7 +1670,7 @@ void nsCSSRendering::PaintBorder(nsIPresContext* aPresContext,
                                  const nsRect& aDirtyRect,
                                  const nsRect& aBorderArea,
                                  const nsStyleBorder& aBorderStyle,
-                                 nsIStyleContext* aStyleContext,
+                                 nsStyleContext* aStyleContext,
                                  PRIntn aSkipSides,
                                  nsRect* aGap,
                                  nscoord aHardBorderSize,
@@ -2070,7 +2068,7 @@ void nsCSSRendering::PaintOutline(nsIPresContext* aPresContext,
                                  const nsRect& aBorderArea,
                                  const nsStyleBorder& aBorderStyle,
                                  const nsStyleOutline& aOutlineStyle,
-                                 nsIStyleContext* aStyleContext,
+                                 nsStyleContext* aStyleContext,
                                  PRIntn aSkipSides,
                                  nsRect* aGap)
 {
@@ -2233,7 +2231,7 @@ void nsCSSRendering::PaintBorderEdges(nsIPresContext* aPresContext,
                                       const nsRect& aDirtyRect,
                                       const nsRect& aBorderArea,
                                       nsBorderEdges * aBorderEdges,
-                                      nsIStyleContext* aStyleContext,
+                                      nsStyleContext* aStyleContext,
                                       PRIntn aSkipSides,
                                       nsRect* aGap)
 {
@@ -2527,11 +2525,11 @@ GetRootScrollableFrame(nsIPresContext* aPresContext, nsIFrame* aRootFrame)
 }
 
 const nsStyleBackground*
-nsCSSRendering::FindNonTransparentBackground(nsIStyleContext* aContext,
+nsCSSRendering::FindNonTransparentBackground(nsStyleContext* aContext,
                                              PRBool aStartAtParent /*= PR_FALSE*/)
 {
   const nsStyleBackground* result = nsnull;
-  nsCOMPtr<nsIStyleContext> context;
+  nsStyleContext* context;
   if (aStartAtParent) {
     context = aContext->GetParent();
   } else {
@@ -2543,7 +2541,7 @@ nsCSSRendering::FindNonTransparentBackground(nsIStyleContext* aContext,
     // Have to .get() because some compilers won't match the template
     // otherwise (they don't look for implicit type conversions while doing
     // template matching?).
-    ::GetStyleData(context.get(), &result);
+    ::GetStyleData(context, &result);
     if (0 == (result->mBackgroundFlags & NS_STYLE_BG_COLOR_TRANSPARENT))
       break;
 
@@ -2609,7 +2607,7 @@ FindCanvasBackground(nsIPresContext* aPresContext,
   
     // for printing and print preview.. this should be a pageContentFrame
     nsCOMPtr<nsIAtom> frameType;
-    nsCOMPtr<nsIStyleContext> parentContext;
+    nsStyleContext* parentContext;
 
     firstChild->GetFrameType(getter_AddRefs(frameType));
     if ( (frameType == nsLayoutAtoms::pageContentFrame) ){
@@ -2617,11 +2615,11 @@ FindCanvasBackground(nsIPresContext* aPresContext,
       // pageContentframe does not have content
       while(firstChild){
         for (nsIFrame* kidFrame = firstChild; nsnull != kidFrame; ) {
-          kidFrame->GetStyleContext(getter_AddRefs(parentContext));
+          parentContext = kidFrame->GetStyleContext();
           // Need to .get() because some compilers will not do the
           // implicit .get() to match the template.
           // See also rev 3.188 of this file.
-          ::GetStyleData(parentContext.get(), &result);
+          ::GetStyleData(parentContext, &result);
           if (!result->IsTransparent()) {
             GetStyleData(kidFrame, aBackground);
             return PR_TRUE;
@@ -3504,7 +3502,7 @@ nsCSSRendering::PaintRoundedBorder(nsIPresContext* aPresContext,
                                  const nsRect& aBorderArea,
                                  const nsStyleBorder* aBorderStyle,
                                  const nsStyleOutline* aOutlineStyle,
-                                 nsIStyleContext* aStyleContext,
+                                 nsStyleContext* aStyleContext,
                                  PRIntn aSkipSides,
                                  PRInt16 aBorderRadius[4],
                                  nsRect* aGap,
@@ -3643,7 +3641,7 @@ nsCSSRendering::PaintRoundedBorder(nsIPresContext* aPresContext,
  */
 void 
 nsCSSRendering::RenderSide(nsFloatPoint aPoints[],nsIRenderingContext& aRenderingContext,
-                        const nsStyleBorder* aBorderStyle,const nsStyleOutline* aOutlineStyle,nsIStyleContext* aStyleContext,
+                        const nsStyleBorder* aBorderStyle,const nsStyleOutline* aOutlineStyle,nsStyleContext* aStyleContext,
                         PRUint8 aSide,nsMargin  &aBorThick,nscoord aTwipsPerPixel,
                         PRBool aIsOutline)
 {
diff --git a/mozilla/layout/base/nsCSSRendering.h b/mozilla/layout/base/nsCSSRendering.h
index a12f889f35e..ce3e138e10c 100644
--- a/mozilla/layout/base/nsCSSRendering.h
+++ b/mozilla/layout/base/nsCSSRendering.h
@@ -39,7 +39,7 @@
 
 #include "nsIRenderingContext.h"
 struct nsPoint;
-class nsIStyleContext;
+class nsStyleContext;
 class nsIPresContext;
 
 class nsCSSRendering {
@@ -58,7 +58,7 @@ public:
                           const nsRect& aDirtyRect,
                           const nsRect& aBorderArea,
                           const nsStyleBorder& aBorderStyle,
-                          nsIStyleContext* aStyleContext,
+                          nsStyleContext* aStyleContext,
                           PRIntn aSkipSides,
                           nsRect* aGap = 0,
                           nscoord aHardBorderSize = 0,
@@ -79,7 +79,7 @@ public:
                           const nsRect& aBorderArea,
                           const nsStyleBorder& aBorderStyle,
                           const nsStyleOutline& aOutlineStyle,
-                          nsIStyleContext* aStyleContext,
+                          nsStyleContext* aStyleContext,
                           PRIntn aSkipSides,
                           nsRect* aGap = 0);
 
@@ -100,7 +100,7 @@ public:
                                const nsRect& aDirtyRect,
                                const nsRect& aBorderArea,
                                nsBorderEdges * aBorderEdges,
-                               nsIStyleContext* aStyleContext,
+                               nsStyleContext* aStyleContext,
                                PRIntn aSkipSides,
                                nsRect* aGap = 0);
 
@@ -123,7 +123,7 @@ public:
    * you want.
    */
   static const nsStyleBackground*
-  FindNonTransparentBackground(nsIStyleContext* aContext,
+  FindNonTransparentBackground(nsStyleContext* aContext,
                                PRBool aStartAtParent = PR_FALSE);
 
   /**
@@ -232,13 +232,13 @@ protected:
                           const nsRect& aBorderArea,
                           const nsStyleBorder* aBorderStyle,
                           const nsStyleOutline* aOutlineStyle,
-                          nsIStyleContext* aStyleContext,
+                          nsStyleContext* aStyleContext,
                           PRIntn aSkipSides,
                           PRInt16 aBorderRadius[4],nsRect* aGap = 0,
                           PRBool aIsOutline=PR_FALSE);
 
   static void RenderSide(nsFloatPoint aPoints[],nsIRenderingContext& aRenderingContext,
-                        const nsStyleBorder* aBorderStyle,const nsStyleOutline* aOutlineStyle,nsIStyleContext* aStyleContext,
+                        const nsStyleBorder* aBorderStyle,const nsStyleOutline* aOutlineStyle,nsStyleContext* aStyleContext,
                         PRUint8 aSide,nsMargin  &aBorThick,nscoord aTwipsPerPixel,
                         PRBool aIsOutline=PR_FALSE);
 
diff --git a/mozilla/layout/base/nsFrameManager.cpp b/mozilla/layout/base/nsFrameManager.cpp
index 7975898b4f6..10a01caf312 100644
--- a/mozilla/layout/base/nsFrameManager.cpp
+++ b/mozilla/layout/base/nsFrameManager.cpp
@@ -34,7 +34,7 @@
 #include "nsIPresContext.h"
 #include "nsIPresShell.h"
 #include "nsIStyleSet.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleChangeList.h"
 #include "nsIEventQueueService.h"
 #include "nsIServiceManager.h"
@@ -77,6 +77,7 @@
 #include "nsDummyLayoutRequest.h"
 #include "nsLayoutErrors.h"
 #include "nsLayoutUtils.h"
+#include "nsAutoPtr.h"
 
   #ifdef DEBUG
     //#define NOISY_DEBUG
@@ -199,7 +200,7 @@ MOZ_DECL_CTOR_COUNTER(UndisplayedNode)
 
 class UndisplayedNode {
 public:
-  UndisplayedNode(nsIContent* aContent, nsIStyleContext* aStyle)
+  UndisplayedNode(nsIContent* aContent, nsStyleContext* aStyle)
     : mContent(aContent),
       mStyle(aStyle),
       mNext(nsnull)
@@ -214,7 +215,7 @@ public:
   }
 
   nsCOMPtr<nsIContent>      mContent;
-  nsCOMPtr<nsIStyleContext> mStyle;
+  nsRefPtr<nsStyleContext>  mStyle;
   UndisplayedNode*          mNext;
 };
 
@@ -225,7 +226,7 @@ public:
 
   UndisplayedNode* GetFirstNode(nsIContent* aParentContent);
 
-  nsresult AddNodeFor(nsIContent* aParentContent, nsIContent* aChild, nsIStyleContext* aStyle);
+  nsresult AddNodeFor(nsIContent* aParentContent, nsIContent* aChild, nsStyleContext* aStyle);
 
   nsresult RemoveNodeFor(nsIContent* aParentContent, UndisplayedNode* aNode);
   nsresult RemoveNodesFor(nsIContent* aParentContent);
@@ -300,8 +301,8 @@ public:
   NS_IMETHOD ClearPlaceholderFrameMap();
 
   // Undisplayed content functions
-  NS_IMETHOD GetUndisplayedContent(nsIContent* aContent, nsIStyleContext** aStyleContext);
-  NS_IMETHOD SetUndisplayedContent(nsIContent* aContent, nsIStyleContext* aStyleContext);
+  virtual nsStyleContext* GetUndisplayedContent(nsIContent* aContent);
+  virtual void SetUndisplayedContent(nsIContent* aContent, nsStyleContext* aStyleContext);
   NS_IMETHOD ClearUndisplayedContentIn(nsIContent* aContent, nsIContent* aParentContent);
   NS_IMETHOD ClearAllUndisplayedContentIn(nsIContent* aParentContent);
   NS_IMETHOD ClearUndisplayedContentMap();
@@ -337,7 +338,7 @@ public:
 
   NS_IMETHOD ReParentStyleContext(nsIPresContext* aPresContext,
                                   nsIFrame* aFrame, 
-                                  nsIStyleContext* aNewParentContext);
+                                  nsStyleContext* aNewParentContext);
   NS_IMETHOD ComputeStyleChangeFor(nsIPresContext* aPresContext,
                                    nsIFrame* aFrame, 
                                    PRInt32 aAttrNameSpaceID,
@@ -834,36 +835,32 @@ FrameManager::ClearPlaceholderFrameMap()
 
 //----------------------------------------------------------------------
 
-NS_IMETHODIMP
-FrameManager::GetUndisplayedContent(nsIContent* aContent, nsIStyleContext** aResult)
+nsStyleContext*
+FrameManager::GetUndisplayedContent(nsIContent* aContent)
 {
-  NS_ENSURE_ARG_POINTER(aContent);
-  *aResult = nsnull;  // initialize out param
-
-  if (!mUndisplayedMap)
-    return NS_OK;
+  if (!aContent || !mUndisplayedMap)
+    return nsnull;
 
   nsCOMPtr<nsIContent> parent;
   aContent->GetParent(*getter_AddRefs(parent));
   if (!parent)
-    return NS_OK;
+    return nsnull;
 
   for (UndisplayedNode* node = mUndisplayedMap->GetFirstNode(parent);
          node; node = node->mNext) {
-    if (node->mContent == aContent) {
-      *aResult = node->mStyle;
-      NS_ADDREF(*aResult);
-      return NS_OK;
-    }
+    if (node->mContent == aContent)
+      return node->mStyle;
   }
-  return NS_OK;
+
+  return nsnull;
 }
   
-NS_IMETHODIMP
+void
 FrameManager::SetUndisplayedContent(nsIContent* aContent, 
-                                    nsIStyleContext* aStyleContext)
+                                    nsStyleContext* aStyleContext)
 {
-  NS_ENSURE_TRUE(mPresShell, NS_ERROR_NOT_AVAILABLE);
+  if (!mPresShell)
+    return;
   
 #ifdef DEBUG_UNDISPLAYED_MAP
    static int i = 0;
@@ -874,17 +871,14 @@ FrameManager::SetUndisplayedContent(nsIContent* aContent,
     mUndisplayedMap = new UndisplayedMap;
   }
   if (mUndisplayedMap) {
-    nsresult result = NS_OK;
     nsIContent* parent = nsnull;
     aContent->GetParent(parent);
     NS_ASSERTION(parent, "undisplayed content must have a parent");
     if (parent) {
-      result = mUndisplayedMap->AddNodeFor(parent, aContent, aStyleContext);
+      mUndisplayedMap->AddNodeFor(parent, aContent, aStyleContext);
       NS_RELEASE(parent);
     }
-    return result;
   }
-  return NS_ERROR_OUT_OF_MEMORY;
 }
 
 NS_IMETHODIMP
@@ -908,8 +902,7 @@ FrameManager::ClearUndisplayedContentIn(nsIContent* aContent, nsIContent* aParen
 #endif
 #ifdef DEBUG
         // make sure that there are no more entries for the same content
-        nsIStyleContext *context = nsnull;
-        GetUndisplayedContent(aContent, &context);
+        nsStyleContext *context = GetUndisplayedContent(aContent);
         NS_ASSERTION(context == nsnull, "Found more undisplayed content data after removal");
 #endif
         return rv;
@@ -1306,7 +1299,7 @@ FrameManager::CantRenderReplacedElement(nsIPresContext* aPresContext,
 
 #ifdef NS_DEBUG
 static void
-DumpContext(nsIFrame* aFrame, nsIStyleContext* aContext)
+DumpContext(nsIFrame* aFrame, nsStyleContext* aContext)
 {
   if (aFrame) {
     fputs("frame: ", stdout);
@@ -1322,14 +1315,12 @@ DumpContext(nsIFrame* aFrame, nsIStyleContext* aContext)
   if (aContext) {
     fprintf(stdout, " style: %p ", NS_STATIC_CAST(void*, aContext));
 
-    nsIAtom* pseudoTag;
-    aContext->GetPseudoType(pseudoTag);
+    nsCOMPtr<nsIAtom> pseudoTag = aContext->GetPseudoType();
     if (pseudoTag) {
       nsAutoString  buffer;
       pseudoTag->ToString(buffer);
       fputs(NS_LossyConvertUCS2toASCII(buffer).get(), stdout);
       fputs(" ", stdout);
-      NS_RELEASE(pseudoTag);
     }
 
 /* XXXdwh fix debugging here.  Need to add a List method to nsRuleNode
@@ -1356,11 +1347,11 @@ DumpContext(nsIFrame* aFrame, nsIStyleContext* aContext)
 }
 
 static void
-VerifySameTree(nsIStyleContext* aContext1, nsIStyleContext* aContext2)
+VerifySameTree(nsStyleContext* aContext1, nsStyleContext* aContext2)
 {
-  nsCOMPtr<nsIStyleContext> top1 = aContext1;
-  nsCOMPtr<nsIStyleContext> top2 = aContext2;
-  nsCOMPtr<nsIStyleContext> parent;
+  nsStyleContext* top1 = aContext1;
+  nsStyleContext* top2 = aContext2;
+  nsStyleContext* parent;
   for (;;) {
     parent = top1->GetParent();
     if (!parent)
@@ -1379,14 +1370,11 @@ VerifySameTree(nsIStyleContext* aContext1, nsIStyleContext* aContext2)
 
 static void
 VerifyContextParent(nsIPresContext* aPresContext, nsIFrame* aFrame, 
-                    nsIStyleContext* aContext, nsIStyleContext* aParentContext)
+                    nsStyleContext* aContext, nsStyleContext* aParentContext)
 {
   // get the contexts not provided
   if (!aContext) {
-    aFrame->GetStyleContext(&aContext);
-  } else {
-    // addref here so we can release at end
-    NS_ADDREF(aContext);
+    aContext = aFrame->GetStyleContext();
   }
 
   if (!aParentContext) {
@@ -1400,15 +1388,12 @@ VerifyContextParent(nsIPresContext* aPresContext, nsIFrame* aFrame,
     aFrame->GetParentStyleContextFrame(aPresContext,
                                        &providerFrame, &providerIsChild);
     if (providerFrame)
-      providerFrame->GetStyleContext(&aParentContext);
+      aParentContext = providerFrame->GetStyleContext();
     // aParentContext could still be null
-  } else {
-    // addref the parent context so we can release it at end
-    NS_ADDREF(aParentContext);
   }
 
   NS_ASSERTION(aContext, "Failure to get required contexts");
-  nsCOMPtr<nsIStyleContext> actualParentContext = aContext->GetParent();
+  nsStyleContext* actualParentContext = aContext->GetParent();
 
   if (aParentContext) {
     if (aParentContext != actualParentContext) {
@@ -1434,17 +1419,12 @@ VerifyContextParent(nsIPresContext* aPresContext, nsIFrame* aFrame,
       fputs("Should be null\n\n", stdout);
     }
   }
-
-  NS_IF_RELEASE(aParentContext);
-  NS_IF_RELEASE(aContext);
 }
 
 static void
-VerifyStyleTree(nsIPresContext* aPresContext, nsIFrame* aFrame, nsIStyleContext* aParentContext)
+VerifyStyleTree(nsIPresContext* aPresContext, nsIFrame* aFrame, nsStyleContext* aParentContext)
 {
-  nsIStyleContext*  context;
-  aFrame->GetStyleContext(&context);
-
+  nsStyleContext*  context = aFrame->GetStyleContext();
   VerifyContextParent(aPresContext, aFrame, context, nsnull);
 
   PRInt32 listIndex = 0;
@@ -1488,18 +1468,15 @@ VerifyStyleTree(nsIPresContext* aPresContext, nsIFrame* aFrame, nsIStyleContext*
   
   // do additional contexts 
   PRInt32 contextIndex = -1;
-  while (1 == 1) {
-    nsIStyleContext* extraContext = nsnull;
-    aFrame->GetAdditionalStyleContext(++contextIndex, &extraContext);
+  while (1) {
+    nsStyleContext* extraContext = aFrame->GetAdditionalStyleContext(++contextIndex);
     if (extraContext) {
       VerifyContextParent(aPresContext, aFrame, extraContext, context);
-      NS_RELEASE(extraContext);
     }
     else {
       break;
     }
   }
-  NS_RELEASE(context);
 }
 
 NS_IMETHODIMP
@@ -1507,9 +1484,8 @@ FrameManager::DebugVerifyStyleTree(nsIPresContext* aPresContext, nsIFrame* aFram
 {
   NS_ENSURE_TRUE(mPresShell, NS_ERROR_NOT_AVAILABLE);
   if (aFrame) {
-    nsCOMPtr<nsIStyleContext> context;
-    aFrame->GetStyleContext(getter_AddRefs(context));
-    nsCOMPtr<nsIStyleContext> parentContext = context->GetParent();
+    nsStyleContext* context = aFrame->GetStyleContext();
+    nsStyleContext* parentContext = context->GetParent();
     VerifyStyleTree(aPresContext, aFrame, parentContext);
   }
   return NS_OK;
@@ -1520,7 +1496,7 @@ FrameManager::DebugVerifyStyleTree(nsIPresContext* aPresContext, nsIFrame* aFram
 NS_IMETHODIMP
 FrameManager::ReParentStyleContext(nsIPresContext* aPresContext,
                                    nsIFrame* aFrame, 
-                                   nsIStyleContext* aNewParentContext)
+                                   nsStyleContext* aNewParentContext)
 {
   NS_ENSURE_TRUE(mPresShell, NS_ERROR_NOT_AVAILABLE);
   nsresult result = NS_ERROR_NULL_POINTER;
@@ -1529,15 +1505,13 @@ FrameManager::ReParentStyleContext(nsIPresContext* aPresContext,
     DebugVerifyStyleTree(aPresContext, aFrame);
 #endif
 
-    nsIStyleContext* oldContext = nsnull;
-    aFrame->GetStyleContext(&oldContext);
-
+    nsStyleContext* oldContext = aFrame->GetStyleContext();
     if (oldContext) {
-      nsIStyleContext* newContext = nsnull;
-      result = mStyleSet->ReParentStyleContext(aPresContext, 
-                                               oldContext, aNewParentContext,
-                                               &newContext);
-      if (NS_SUCCEEDED(result) && newContext) {
+      nsRefPtr<nsStyleContext> newContext;
+      result = NS_OK;
+      newContext = mStyleSet->ReParentStyleContext(aPresContext, oldContext,
+                                                   aNewParentContext);
+      if (newContext) {
         if (newContext != oldContext) {
           PRInt32 listIndex = 0;
           nsIAtom* childList = nsnull;
@@ -1561,10 +1535,8 @@ FrameManager::ReParentStyleContext(nsIPresContext* aPresContext,
                   result = ReParentStyleContext(aPresContext, outOfFlowFrame, newContext);
 
                   // reparent placeholder's context under out of flow frame
-                  nsIStyleContext*  outOfFlowContext;
-                  outOfFlowFrame->GetStyleContext(&outOfFlowContext);
+                  nsStyleContext* outOfFlowContext = outOfFlowFrame->GetStyleContext();
                   ReParentStyleContext(aPresContext, child, outOfFlowContext);
-                  NS_RELEASE(outOfFlowContext);
                 }
                 else { // regular frame
                   result = ReParentStyleContext(aPresContext, child, newContext);
@@ -1583,20 +1555,15 @@ FrameManager::ReParentStyleContext(nsIPresContext* aPresContext,
 
           // do additional contexts 
           PRInt32 contextIndex = -1;
-          while (1 == 1) {
-            nsIStyleContext* oldExtraContext = nsnull;
-            result = aFrame->GetAdditionalStyleContext(++contextIndex, &oldExtraContext);
-            if (NS_SUCCEEDED(result)) {
-              if (oldExtraContext) {
-                nsIStyleContext* newExtraContext = nsnull;
-                result = mStyleSet->ReParentStyleContext(aPresContext,
-                                                         oldExtraContext, newContext,
-                                                         &newExtraContext);
-                if (NS_SUCCEEDED(result) && newExtraContext) {
-                  aFrame->SetAdditionalStyleContext(contextIndex, newExtraContext);
-                  NS_RELEASE(newExtraContext);
-                }
-                NS_RELEASE(oldExtraContext);
+          while (1) {
+            nsStyleContext* oldExtraContext = aFrame->GetAdditionalStyleContext(++contextIndex);
+            if (oldExtraContext) {
+              nsRefPtr<nsStyleContext> newExtraContext;
+              newExtraContext = mStyleSet->ReParentStyleContext(aPresContext,
+                                                                oldExtraContext,
+                                                                newContext);
+              if (newExtraContext) {
+                aFrame->SetAdditionalStyleContext(contextIndex, newExtraContext);
               }
             }
             else {
@@ -1608,16 +1575,14 @@ FrameManager::ReParentStyleContext(nsIPresContext* aPresContext,
           VerifyStyleTree(aPresContext, aFrame, aNewParentContext);
 #endif
         }
-        NS_RELEASE(newContext);
       }
-      NS_RELEASE(oldContext);
     }
   }
   return result;
 }
 
 static PRBool
-HasAttributeContent(nsIStyleContext* aStyleContext, 
+HasAttributeContent(nsStyleContext* aStyleContext, 
                     PRInt32 aNameSpaceID,
                     nsIAtom* aAttribute)
 {
@@ -1659,12 +1624,12 @@ HasAttributeContent(nsIStyleContext* aStyleContext,
 }
 
 static nsChangeHint
-CaptureChange(nsIStyleContext* aOldContext, nsIStyleContext* aNewContext,
+CaptureChange(nsStyleContext* aOldContext, nsStyleContext* aNewContext,
               nsIFrame* aFrame, nsIContent* aContent,
               nsStyleChangeList& aChangeList, nsChangeHint aMinChange)
 {
   nsChangeHint ourChange = NS_STYLE_HINT_NONE;
-  aOldContext->CalcStyleDifference(aNewContext, ourChange);
+  ourChange = aOldContext->CalcStyleDifference(aNewContext);
   if (NS_UpdateHint(aMinChange, ourChange)) {
     aChangeList.AppendChange(aFrame, aContent, ourChange);
   }
@@ -1685,11 +1650,16 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
   // duplication.  (Or should we just let |GetContext| handle that?)
   // Getting the hint would be nice too, but that's harder.
 
-  nsIStyleContext* oldContext = nsnull; 
-  nsresult result = aFrame->GetStyleContext(&oldContext);
-  if (NS_SUCCEEDED(result) && oldContext) {
-    nsIAtom* pseudoTag = nsnull;
-    oldContext->GetPseudoType(pseudoTag);
+  // XXXbryner we may be able to avoid some of the refcounting goop here.
+  // We do need a reference to oldContext for the lifetime of this function, and it's possible
+  // that the frame has the last reference to it, so AddRef it here.
+
+  nsStyleContext* oldContext = aFrame->GetStyleContext();
+  nsresult result = NS_OK;
+
+  if (oldContext) {
+    oldContext->AddRef();
+    nsCOMPtr<nsIAtom> pseudoTag = oldContext->GetPseudoType();
     nsIContent* localContent = nsnull;
     nsIContent* content = nsnull;
     result = aFrame->GetContent(&localContent);
@@ -1707,7 +1677,7 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
       }
     }
 
-    nsCOMPtr<nsIStyleContext> parentContext; 
+    nsStyleContext* parentContext;
     nsIFrame* resolvedChild = nsnull;
     // Get the frame providing the parent style context.  If it is a
     // child, then resolve the provider first.
@@ -1717,7 +1687,9 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
                                        &providerFrame, &providerIsChild); 
     if (!providerIsChild) {
       if (providerFrame)
-        providerFrame->GetStyleContext(getter_AddRefs(parentContext));  
+        parentContext = providerFrame->GetStyleContext();
+      else
+        parentContext = nsnull;
     }
     else {
       // resolve the provider here (before aFrame below)
@@ -1726,19 +1698,18 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
                             aMinChange, aResultChange);
       // The provider's new context becomes the parent context of
       // aFrame's context.
-      providerFrame->GetStyleContext(getter_AddRefs(parentContext)); 
+      parentContext = providerFrame->GetStyleContext();
       // Set |resolvedChild| so we don't bother resolving the
       // provider again.
       resolvedChild = providerFrame;
     }
     
     // do primary context
-    nsIStyleContext* newContext = nsnull;
+    nsStyleContext* newContext = nsnull;
     if (pseudoTag == nsCSSAnonBoxes::mozNonElement) {
       NS_ASSERTION(localContent,
                    "non pseudo-element frame without content node");
-      aPresContext->ResolveStyleContextForNonElement(parentContext,
-                                                     &newContext);
+      newContext = aPresContext->ResolveStyleContextForNonElement(parentContext).get();
     }
     else if (pseudoTag) {
       nsIContent* pseudoContent =
@@ -1746,9 +1717,9 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
       if (pseudoTag == nsCSSPseudoElements::before ||
           pseudoTag == nsCSSPseudoElements::after) {
         // XXX what other pseudos do we need to treat like this?
-        aPresContext->ProbePseudoStyleContextFor(pseudoContent, pseudoTag,
-                                                 parentContext, 
-                                                 &newContext);
+        newContext = aPresContext->ProbePseudoStyleContextFor(pseudoContent,
+                                                              pseudoTag,
+                                                              parentContext).get();
         if (!newContext) {
           // This pseudo should no longer exist; gotta reframe
           NS_UpdateHint(aMinChange, nsChangeHint_ReconstructFrame);
@@ -1756,20 +1727,18 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
                                    nsChangeHint_ReconstructFrame);
           // We're reframing anyway; just keep the same context
           newContext = oldContext;
-          NS_ADDREF(newContext);
+          newContext->AddRef();
         }
       } else {
-        aPresContext->ResolvePseudoStyleContextFor(pseudoContent, pseudoTag,
-                                                   parentContext, 
-                                                   &newContext);
+        newContext = aPresContext->ResolvePseudoStyleContextFor(pseudoContent,
+                                                                pseudoTag,
+                                                                parentContext).get();
       }
-      NS_RELEASE(pseudoTag);
     }
     else {
       NS_ASSERTION(localContent,
                    "non pseudo-element frame without content node");
-      aPresContext->ResolveStyleContextFor(content, parentContext,
-                                           &newContext);
+      newContext = aPresContext->ResolveStyleContextFor(content, parentContext).get();
     }
     NS_ASSERTION(newContext, "failed to get new style context");
     if (newContext) {
@@ -1783,9 +1752,9 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
           // we can use FindChildWithRules to keep a lot of the old
           // style contexts around.  However, we need to start from the
           // same root.
-          NS_RELEASE(newContext);
+          newContext->Release();
           newContext = oldContext;
-          NS_ADDREF(newContext);
+          newContext->AddRef();
         }
       }
 
@@ -1816,7 +1785,7 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
           aChangeList.AppendChange(aFrame, content, NS_STYLE_HINT_REFLOW);
         }
       }
-      NS_RELEASE(oldContext);
+      oldContext->Release();
     }
     else {
       NS_ERROR("resolve style context failed");
@@ -1827,40 +1796,37 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
     // do additional contexts 
     PRInt32 contextIndex = -1;
     while (1 == 1) {
-      nsIStyleContext* oldExtraContext = nsnull;
-      result = aFrame->GetAdditionalStyleContext(++contextIndex, &oldExtraContext);
-      if (NS_SUCCEEDED(result)) {
-        if (oldExtraContext) {
-          nsIStyleContext* newExtraContext = nsnull;
-          oldExtraContext->GetPseudoType(pseudoTag);
-          NS_ASSERTION(pseudoTag &&
-                       pseudoTag != nsCSSAnonBoxes::mozNonElement,
-                       "extra style context is not pseudo element");
-          result = aPresContext->ResolvePseudoStyleContextFor(content, pseudoTag, newContext,
-                                                              &newExtraContext);
-          NS_RELEASE(pseudoTag);
-          if (NS_SUCCEEDED(result) && newExtraContext) {
-            if (oldExtraContext != newExtraContext) {
-              aMinChange = CaptureChange(oldExtraContext, newExtraContext, aFrame, 
-                                         content, aChangeList, aMinChange);
-              if (!(aMinChange & (nsChangeHint_ReconstructFrame | nsChangeHint_ReconstructDoc))) {
-                aFrame->SetAdditionalStyleContext(contextIndex, newExtraContext);
-              }
+      nsStyleContext* oldExtraContext = nsnull;
+      oldExtraContext = aFrame->GetAdditionalStyleContext(++contextIndex);
+      if (oldExtraContext) {
+        nsStyleContext* newExtraContext = nsnull;
+        pseudoTag = oldExtraContext->GetPseudoType();
+        NS_ASSERTION(pseudoTag &&
+                     pseudoTag != nsCSSAnonBoxes::mozNonElement,
+                     "extra style context is not pseudo element");
+        newExtraContext = aPresContext->ResolvePseudoStyleContextFor(content,
+                                                                     pseudoTag,
+                                                                     newContext).get();
+        if (newExtraContext) {
+          if (oldExtraContext != newExtraContext) {
+            aMinChange = CaptureChange(oldExtraContext, newExtraContext, aFrame, 
+                                       content, aChangeList, aMinChange);
+            if (!(aMinChange & (nsChangeHint_ReconstructFrame | nsChangeHint_ReconstructDoc))) {
+              aFrame->SetAdditionalStyleContext(contextIndex, newExtraContext);
             }
-            else {
-#if 0
-              // XXXldb |oldContext| is null by this point, so this will
-              // never do anything.
-              if (pseudoTag && pseudoTag != nsCSSAnonBoxes::mozNonElement &&
-                  aAttribute && (aMinChange < NS_STYLE_HINT_REFLOW) &&
-                  HasAttributeContent(oldContext, aAttrNameSpaceID, aAttribute)) {
-                aChangeList.AppendChange(aFrame, content, NS_STYLE_HINT_REFLOW);
-              }
-#endif
-            }
-            NS_RELEASE(newExtraContext);
           }
-          NS_RELEASE(oldExtraContext);
+          else {
+#if 0
+            // XXXldb |oldContext| is null by this point, so this will
+            // never do anything.
+            if (pseudoTag && pseudoTag != nsCSSAnonBoxes::mozNonElement &&
+                aAttribute && (aMinChange < NS_STYLE_HINT_REFLOW) &&
+                HasAttributeContent(oldContext, aAttrNameSpaceID, aAttribute)) {
+              aChangeList.AppendChange(aFrame, content, NS_STYLE_HINT_REFLOW);
+            }
+#endif
+          }
+          newExtraContext->Release();
         }
       }
       else {
@@ -1873,23 +1839,22 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
       for (UndisplayedNode* undisplayed =
                                    mUndisplayedMap->GetFirstNode(localContent);
            undisplayed; undisplayed = undisplayed->mNext) {
-        nsCOMPtr<nsIStyleContext> undisplayedContext;
-        undisplayed->mStyle->GetPseudoType(pseudoTag);
+        nsRefPtr<nsStyleContext> undisplayedContext;
+        pseudoTag = undisplayed->mStyle->GetPseudoType();
         if (pseudoTag == nsnull) {  // child content
-          aPresContext->ResolveStyleContextFor(undisplayed->mContent,
-                               newContext, getter_AddRefs(undisplayedContext));
+          undisplayedContext = aPresContext->ResolveStyleContextFor(undisplayed->mContent,
+                                                                    newContext).get();
         }
         else if (pseudoTag == nsCSSAnonBoxes::mozNonElement) {
-          aPresContext->ResolveStyleContextForNonElement(newContext, 
-                                           getter_AddRefs(undisplayedContext));
+          undisplayedContext = aPresContext->ResolveStyleContextForNonElement(newContext).get();
         }
         else {  // pseudo element
           NS_NOTREACHED("no pseudo elements in undisplayed map");
           NS_ASSERTION(pseudoTag, "pseudo element without tag");
-          aPresContext->ResolvePseudoStyleContextFor(localContent, pseudoTag,
-                               newContext, getter_AddRefs(undisplayedContext));
+          undisplayedContext = aPresContext->ResolvePseudoStyleContextFor(localContent,
+                                                                          pseudoTag,
+                                                                          newContext).get();
         }
-        NS_IF_RELEASE(pseudoTag);
         if (undisplayedContext) {
           const nsStyleDisplay* display;
           ::GetStyleData(undisplayedContext.get(), &display);
@@ -1925,11 +1890,9 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
                                                                 aPresContext);
           if (!beforeFrame) {
             // Look for a new :before style context
-            nsCOMPtr<nsIStyleContext> newBeforeContext;
-            aPresContext->ProbePseudoStyleContextFor(localContent,
+            nsRefPtr<nsStyleContext> newBeforeContext = aPresContext->ProbePseudoStyleContextFor(localContent,
                                                      nsCSSPseudoElements::before,
-                                                     newContext,
-                                                     getter_AddRefs(newBeforeContext));
+                                                     newContext);
             if (newBeforeContext) {
               // Have to create the new :before frame
               NS_UpdateHint(aMinChange, nsChangeHint_ReconstructFrame);
@@ -1952,11 +1915,9 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
           // Getting the :after frame is
           // more expensive than getting the pseudo context, so get the
           // pseudo context first.
-          nsCOMPtr<nsIStyleContext> newAfterContext;
-          aPresContext->ProbePseudoStyleContextFor(localContent,
+          nsRefPtr<nsStyleContext> newAfterContext = aPresContext->ProbePseudoStyleContextFor(localContent,
                                                    nsCSSPseudoElements::after,
-                                                   newContext,
-                                                   getter_AddRefs(newAfterContext));
+                                                   newContext);
           if (newAfterContext) {
             // Check whether we already have an :after frame
             nsIFrame* afterFrame = nsLayoutUtils::GetAfterFrame(aFrame,
@@ -2033,7 +1994,7 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
       // XXX need to do overflow frames???
     }
 
-    NS_RELEASE(newContext);
+    newContext->Release();
     NS_IF_RELEASE(localContent);
   }
 }
@@ -2667,7 +2628,7 @@ UndisplayedMap::AppendNodeFor(UndisplayedNode* aNode, nsIContent* aParentContent
 
 nsresult 
 UndisplayedMap::AddNodeFor(nsIContent* aParentContent, nsIContent* aChild, 
-                           nsIStyleContext* aStyle)
+                           nsStyleContext* aStyle)
 {
   UndisplayedNode*  node = new UndisplayedNode(aChild, aStyle);
   if (! node) {
diff --git a/mozilla/layout/base/nsIPresShell.h b/mozilla/layout/base/nsIPresShell.h
index b0ed3065a8c..8e18a9ce5fb 100644
--- a/mozilla/layout/base/nsIPresShell.h
+++ b/mozilla/layout/base/nsIPresShell.h
@@ -59,7 +59,7 @@ class nsString;
 class nsAString;
 class nsStringArray;
 class nsICaret;
-class nsIStyleContext;
+class nsStyleContext;
 class nsIFrameSelection;
 class nsIFrameManager;
 class nsILayoutHistoryState;
@@ -258,13 +258,6 @@ public:
   NS_IMETHOD GetPrimaryFrameFor(nsIContent* aContent,
                                 nsIFrame**  aPrimaryFrame) const = 0;
 
-  /** Returns the style context associated with the frame.
-    * Used by code outside of layout that can't use nsIFrame methods to get
-    * the style context directly.
-    */
-  NS_IMETHOD GetStyleContextFor(nsIFrame*         aFrame,
-                                nsIStyleContext** aStyleContext) const = 0;
-
   /**
    * Returns a layout object associated with the primary frame for the content object.
    *
diff --git a/mozilla/layout/base/nsImageLoader.cpp b/mozilla/layout/base/nsImageLoader.cpp
index 555f0cae0d7..a298b098fde 100644
--- a/mozilla/layout/base/nsImageLoader.cpp
+++ b/mozilla/layout/base/nsImageLoader.cpp
@@ -41,7 +41,7 @@
 
 #include "nsIViewManager.h"
 
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 
 NS_IMPL_ISUPPORTS2(nsImageLoader, imgIDecoderObserver, imgIContainerObserver)
 
@@ -240,8 +240,8 @@ nsImageLoader::RedrawDirtyFrame(const nsRect* aDamageRect)
   // Invalidate the entire frame only if the frame has a tiled background
   // image, otherwise just invalidate the intersection of the frame's bounds
   // with the damaged rect.
-  nsCOMPtr<nsIStyleContext> styleContext;
-  mFrame->GetStyleContext(getter_AddRefs(styleContext));
+  nsStyleContext* styleContext;
+  mFrame->GetStyleContext(&styleContext);
   const nsStyleBackground* bg = (const nsStyleBackground*)styleContext->GetStyleData(eStyleStruct_Background);
 
   if ((bg->mBackgroundFlags & NS_STYLE_BG_IMAGE_NONE) ||
diff --git a/mozilla/layout/base/nsPresContext.cpp b/mozilla/layout/base/nsPresContext.cpp
index 127f8737c3f..daa34f750ff 100644
--- a/mozilla/layout/base/nsPresContext.cpp
+++ b/mozilla/layout/base/nsPresContext.cpp
@@ -48,7 +48,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIURL.h"
 #include "nsIDocument.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsLayoutAtoms.h"
 #include "nsILookAndFeel.h"
 #include "nsWidgetsCID.h"
@@ -69,6 +69,7 @@
 #include "nsContentPolicyUtils.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsIDOMDocument.h"
+#include "nsAutoPtr.h"
 #ifdef IBMBIDI
 #include "nsBidiPresUtils.h"
 #endif // IBMBIDI
@@ -934,26 +935,18 @@ nsPresContext::GetBaseURL(nsIURI** aResult)
   return NS_OK;
 }
 
-NS_IMETHODIMP
+already_AddRefed<nsStyleContext>
 nsPresContext::ResolveStyleContextFor(nsIContent* aContent,
-                                      nsIStyleContext* aParentContext,
-                                      nsIStyleContext** aResult)
+                                      nsStyleContext* aParentContext)
 {
-  NS_PRECONDITION(aResult, "null out param");
-
-  nsIStyleContext* result = nsnull;
   nsCOMPtr<nsIStyleSet> set;
   nsresult rv = mShell->GetStyleSet(getter_AddRefs(set));
-  if (NS_SUCCEEDED(rv)) {
-    if (set) {
-      result = set->ResolveStyleFor(this, aContent, aParentContext);
-      if (nsnull == result) {
-        rv = NS_ERROR_OUT_OF_MEMORY;
-      }
-    }
+  if (NS_SUCCEEDED(rv) && set) {
+    // return the addref'd style context
+    return set->ResolveStyleFor(this, aContent, aParentContext);
   }
-  *aResult = result;
-  return rv;
+
+  return nsnull;
 }
 
 NS_IMETHODIMP
@@ -961,92 +954,71 @@ nsPresContext::ResolveStyleContextAndGetStyleData(nsIContent* aContent,
                                                   int aSID,
                                                   const nsStyleStruct*& aStyleStruct)
 {
-  nsCOMPtr<nsIStyleContext> sc;
-  nsresult rv = ResolveStyleContextFor(aContent, nsnull, getter_AddRefs(sc));
-  NS_ENSURE_SUCCESS(rv, rv);
+  nsRefPtr<nsStyleContext> sc = ResolveStyleContextFor(aContent, nsnull);
+  if (!sc) return NS_ERROR_FAILURE;
 
   aStyleStruct = sc->GetStyleData((nsStyleStructID) aSID);
   return aStyleStruct ? NS_OK : NS_ERROR_FAILURE;
 }
 
-NS_IMETHODIMP
-nsPresContext::ResolveStyleContextForNonElement(
-                                      nsIStyleContext* aParentContext,
-                                      nsIStyleContext** aResult)
+already_AddRefed<nsStyleContext>
+nsPresContext::ResolveStyleContextForNonElement(nsStyleContext* aParentContext)
 {
-  NS_PRECONDITION(aResult, "null out param");
-
-  nsIStyleContext* result = nsnull;
   nsCOMPtr<nsIStyleSet> set;
   nsresult rv = mShell->GetStyleSet(getter_AddRefs(set));
   if (NS_SUCCEEDED(rv) && set) {
-    result = set->ResolveStyleForNonElement(this, aParentContext);
-    if (!result)
-      rv = NS_ERROR_OUT_OF_MEMORY;
+    // return addrefed style context
+    return set->ResolveStyleForNonElement(this, aParentContext);
   }
-  *aResult = result;
-  return rv;
+
+  return nsnull;
 }
 
-NS_IMETHODIMP
+already_AddRefed<nsStyleContext>
 nsPresContext::ResolvePseudoStyleContextFor(nsIContent* aParentContent,
                                             nsIAtom* aPseudoTag,
-                                            nsIStyleContext* aParentContext,
-                                            nsIStyleContext** aResult)
+                                            nsStyleContext* aParentContext)
 {
-  return ResolvePseudoStyleWithComparator(aParentContent, aPseudoTag, aParentContext,
-                                          nsnull, aResult);
+  return ResolvePseudoStyleWithComparator(aParentContent, aPseudoTag,
+                                          aParentContext, nsnull);
 }
 
-NS_IMETHODIMP
+already_AddRefed<nsStyleContext>
 nsPresContext::ResolvePseudoStyleWithComparator(nsIContent* aParentContent,
                                                 nsIAtom* aPseudoTag,
-                                                nsIStyleContext* aParentContext,
-                                                nsICSSPseudoComparator* aComparator,
-                                                nsIStyleContext** aResult)
+                                                nsStyleContext* aParentContext,
+                                                nsICSSPseudoComparator* aComparator)
 {
-  NS_PRECONDITION(aResult, "null out param");
-
-  nsIStyleContext* result = nsnull;
   nsCOMPtr<nsIStyleSet> set;
   nsresult rv = mShell->GetStyleSet(getter_AddRefs(set));
-  if (NS_SUCCEEDED(rv)) {
-    if (set) {
-      result = set->ResolvePseudoStyleFor(this, aParentContent, aPseudoTag,
-                                          aParentContext, aComparator);
-      if (nsnull == result) {
-        rv = NS_ERROR_OUT_OF_MEMORY;
-      }
-    }
+  if (NS_SUCCEEDED(rv) && set) {
+    // return addrefed style context
+    return set->ResolvePseudoStyleFor(this, aParentContent, aPseudoTag,
+                                      aParentContext, aComparator);
   }
-  *aResult = result;
-  return rv;
+
+  return nsnull;
 }
 
-NS_IMETHODIMP
+already_AddRefed<nsStyleContext>
 nsPresContext::ProbePseudoStyleContextFor(nsIContent* aParentContent,
                                           nsIAtom* aPseudoTag,
-                                          nsIStyleContext* aParentContext,
-                                          nsIStyleContext** aResult)
+                                          nsStyleContext* aParentContext)
 {
-  NS_PRECONDITION(aResult, "null out param");
-
-  nsIStyleContext* result = nsnull;
   nsCOMPtr<nsIStyleSet> set;
   nsresult rv = mShell->GetStyleSet(getter_AddRefs(set));
-  if (NS_SUCCEEDED(rv)) {
-    if (set) {
-      result = set->ProbePseudoStyleFor(this, aParentContent, aPseudoTag,
-                                        aParentContext);
-    }
+  if (NS_SUCCEEDED(rv) && set) {
+    // return addrefed style context
+    return set->ProbePseudoStyleFor(this, aParentContent, aPseudoTag,
+                                    aParentContext);
   }
-  *aResult = result;
-  return rv;
+
+  return nsnull;
 }
 
 NS_IMETHODIMP
 nsPresContext::ReParentStyleContext(nsIFrame* aFrame, 
-                                    nsIStyleContext* aNewParentContext)
+                                    nsStyleContext* aNewParentContext)
 {
   NS_PRECONDITION(aFrame, "null ptr");
   if (! aFrame) {
diff --git a/mozilla/layout/base/nsPresContext.h b/mozilla/layout/base/nsPresContext.h
index 98cbb80d9ec..05af526ea97 100644
--- a/mozilla/layout/base/nsPresContext.h
+++ b/mozilla/layout/base/nsPresContext.h
@@ -43,6 +43,7 @@
 #include "nsAString.h"
 #include "nsIRequest.h"
 #include "nsCompatibility.h"
+#include "nsCOMPtr.h"
 #ifdef IBMBIDI
 class nsBidiPresUtils;
 #endif // IBMBIDI
@@ -61,7 +62,7 @@ class nsIImage;
 class nsILinkHandler;
 class nsIPresShell;
 class nsIPref;
-class nsIStyleContext;
+class nsStyleContext;
 class nsIAtom;
 class nsString;
 class nsIEventStateManager;
@@ -192,9 +193,9 @@ public:
    * Resolve style for the given piece of content that will be a child
    * of the aParentContext. Don't use this for pseudo frames.
    */
-  NS_IMETHOD ResolveStyleContextFor(nsIContent* aContent,
-                                    nsIStyleContext* aParentContext,
-                                    nsIStyleContext** aResult) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleContextFor(nsIContent* aContent,
+                         nsStyleContext* aParentContext) = 0;
 
   /**
    * Resolve the given style struct for a content node.
@@ -221,19 +222,19 @@ public:
    * represents everything except the first letter.)
    *
    */
-  NS_IMETHOD ResolveStyleContextForNonElement(
-                                    nsIStyleContext* aParentContext,
-                                    nsIStyleContext** aResult) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleContextForNonElement(nsStyleContext* aParentContext) = 0;
 
   /**
    * Resolve style for a pseudo frame within the given aParentContent & aParentContext.
    * The tag should be lowercase and inclue the colon.
    * ie: NS_NewAtom(":first-line");
    */
-  NS_IMETHOD ResolvePseudoStyleContextFor(nsIContent* aParentContent,
-                                          nsIAtom* aPseudoTag,
-                                          nsIStyleContext* aParentContext,
-                                          nsIStyleContext** aResult) = 0;
+
+  virtual already_AddRefed<nsStyleContext>
+  ResolvePseudoStyleContextFor(nsIContent* aParentContent,
+                               nsIAtom* aPseudoTag,
+                               nsStyleContext* aParentContext) = 0;
 
   /**
    * Resolve style for a pseudo frame within the given aParentContent & aParentContext.
@@ -243,11 +244,11 @@ public:
    * Instead of matching solely on aPseudoTag, a comparator function can be
    * passed in to test.
    */
-  NS_IMETHOD ResolvePseudoStyleWithComparator(nsIContent* aParentContent,
-                                              nsIAtom* aPseudoTag,
-                                              nsIStyleContext* aParentContext,
-                                              nsICSSPseudoComparator* aComparator,
-                                              nsIStyleContext** aResult) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ResolvePseudoStyleWithComparator(nsIContent* aParentContent,
+                                   nsIAtom* aPseudoTag,
+                                   nsStyleContext* aParentContext,
+                                   nsICSSPseudoComparator* aComparator) = 0;
 
   /**
    * Probe style for a pseudo frame within the given aParentContent & aParentContext.
@@ -255,17 +256,17 @@ public:
    * The tag should be lowercase and inclue the colon.
    * ie: NS_NewAtom(":first-line");
    */
-  NS_IMETHOD ProbePseudoStyleContextFor(nsIContent* aParentContent,
-                                        nsIAtom* aPseudoTag,
-                                        nsIStyleContext* aParentContext,
-                                        nsIStyleContext** aResult) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ProbePseudoStyleContextFor(nsIContent* aParentContent,
+                             nsIAtom* aPseudoTag,
+                             nsStyleContext* aParentContext) = 0;
 
   /** 
    * For a given frame tree, get a new style context that is the equivalent
    * but within a new parent
    */
   NS_IMETHOD ReParentStyleContext(nsIFrame* aFrame, 
-                                  nsIStyleContext* aNewParentContext) = 0;
+                                  nsStyleContext* aNewParentContext) = 0;
 
 
   NS_IMETHOD AllocateFromShell(size_t aSize, void** aResult) = 0;
diff --git a/mozilla/layout/base/nsPresShell.cpp b/mozilla/layout/base/nsPresShell.cpp
index 175bcf7574a..360a5c61e86 100644
--- a/mozilla/layout/base/nsPresShell.cpp
+++ b/mozilla/layout/base/nsPresShell.cpp
@@ -79,6 +79,7 @@
 #include "nsHTMLAtoms.h"
 #include "nsCSSPseudoElements.h"
 #include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
 #include "nsReadableUtils.h"
 #include "nsUnicharUtils.h"
 #include "nsWeakReference.h"
@@ -1052,8 +1053,6 @@ public:
   NS_IMETHOD GetPrimaryFrameFor(nsIContent* aContent,
                                 nsIFrame**  aPrimaryFrame) const;
 
-  NS_IMETHOD GetStyleContextFor(nsIFrame*         aFrame,
-                                nsIStyleContext** aStyleContext) const;
   NS_IMETHOD GetLayoutObjectFor(nsIContent*   aContent,
                                 nsISupports** aResult) const;
   NS_IMETHOD GetPlaceholderFrameFor(nsIFrame*  aFrame,
@@ -4619,14 +4618,13 @@ PresShell::GetGeneratedContentIterator(nsIContent*          aContent,
     } else {
       // Avoid finding the :after frame unless we need to (it's
       // expensive). Instead probe for the existence of the pseudo-element
-      nsCOMPtr<nsIStyleContext> styleContext;
-      nsCOMPtr<nsIStyleContext> pseudoStyleContext;
+      nsStyleContext *styleContext;
+      nsRefPtr<nsStyleContext> pseudoStyleContext;
       
-      primaryFrame->GetStyleContext(getter_AddRefs(styleContext));
-      mPresContext->ProbePseudoStyleContextFor(aContent,
-                                               nsCSSPseudoElements::after,
-                                               styleContext,
-                                               getter_AddRefs(pseudoStyleContext));
+      styleContext = primaryFrame->GetStyleContext();
+      pseudoStyleContext = mPresContext->ProbePseudoStyleContextFor(aContent,
+                                                                    nsCSSPseudoElements::after,
+                                                                    styleContext);
       if (pseudoStyleContext) {
         nsIFrame* afterFrame = nsLayoutUtils::GetAfterFrame(primaryFrame,
                                                             mPresContext);
@@ -5558,16 +5556,6 @@ PresShell::GetPrimaryFrameFor(nsIContent* aContent,
   return rv;
 }
 
-NS_IMETHODIMP 
-PresShell::GetStyleContextFor(nsIFrame*         aFrame,
-                              nsIStyleContext** aStyleContext) const
-{
-  if (!aFrame || !aStyleContext) {
-    return NS_ERROR_NULL_POINTER;
-  }
-  return (aFrame->GetStyleContext(aStyleContext));
-}
-
 NS_IMETHODIMP
 PresShell::GetLayoutObjectFor(nsIContent*   aContent,
                               nsISupports** aResult) const 
diff --git a/mozilla/layout/base/nsStyleConsts.h b/mozilla/layout/base/nsStyleConsts.h
index af52e199fab..966fb4abe93 100644
--- a/mozilla/layout/base/nsStyleConsts.h
+++ b/mozilla/layout/base/nsStyleConsts.h
@@ -39,7 +39,7 @@
 
 #include "nsFont.h"
 
-// XXX fold this into nsIStyleContext and group by nsStyleXXX struct
+// XXX fold this into nsStyleContext and group by nsStyleXXX struct
 
 // Indicies into border/padding/margin arrays
 #define NS_SIDE_TOP     0
diff --git a/mozilla/layout/base/public/MANIFEST b/mozilla/layout/base/public/MANIFEST
index 07bae6ef9a1..3e48eacf0bd 100644
--- a/mozilla/layout/base/public/MANIFEST
+++ b/mozilla/layout/base/public/MANIFEST
@@ -36,7 +36,6 @@ nsIReflowCallback.h
 nsIScrollableFrame.h
 nsIScrollableViewProvider.h
 nsIStatefulFrame.h
-nsIStyleContext.h
 nsIStyleFrameConstruction.h
 nsIStyleSet.h
 nsITextFrame.h
diff --git a/mozilla/layout/base/public/Makefile.in b/mozilla/layout/base/public/Makefile.in
index e6053ee0817..7a6fd7a423b 100644
--- a/mozilla/layout/base/public/Makefile.in
+++ b/mozilla/layout/base/public/Makefile.in
@@ -64,7 +64,6 @@ nsIReflowCallback.h \
 nsIScrollableFrame.h \
 nsIScrollableViewProvider.h \
 nsIStatefulFrame.h \
-nsIStyleContext.h \
 nsIStyleFrameConstruction.h \
 nsIStyleSet.h \
 nsLayoutErrors.h \
diff --git a/mozilla/layout/base/public/nsIFrame.h b/mozilla/layout/base/public/nsIFrame.h
index adb6fceba85..2850ae5976f 100644
--- a/mozilla/layout/base/public/nsIFrame.h
+++ b/mozilla/layout/base/public/nsIFrame.h
@@ -47,7 +47,7 @@
 #include "nsISupports.h"
 #include "nsEvent.h"
 #include "nsStyleStruct.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIContent.h"
 
 /**
@@ -418,7 +418,7 @@ public:
   NS_IMETHOD  Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        aPrevInFlow) = 0;
 
   /**
@@ -553,24 +553,21 @@ public:
   NS_IMETHOD GetOffsets(PRInt32 &start, PRInt32 &end) const = 0;
 
   /**
-   * Get the style context associated with this frame. Note that GetStyleContext()
-   * adds a reference to the style context so the caller must do a release.
+   * Get the style context associated with this frame.
    *
-   * @see nsISupports#Release()
    */
-  nsresult GetStyleContext(nsIStyleContext** aStyleContext) const { 
-    *aStyleContext = mStyleContext; NS_IF_ADDREF(*aStyleContext); return NS_OK;
-  }
-  nsresult SetStyleContext(nsIPresContext*  aPresContext, nsIStyleContext* aContext) { 
+  nsStyleContext* GetStyleContext() const { return mStyleContext; }
+  void SetStyleContext(nsIPresContext* aPresContext, nsStyleContext* aContext)
+  { 
     if (aContext != mStyleContext) {
-      NS_IF_RELEASE(mStyleContext);
-      if (nsnull != aContext) {
-        mStyleContext = aContext;
-        NS_ADDREF(aContext);
+      if (mStyleContext)
+        mStyleContext->Release();
+      mStyleContext = aContext;
+      if (aContext) {
+        aContext->AddRef();
         DidSetStyleContext(aPresContext);
       }
     }
-    return NS_OK;
   }
 
   // Style post processing hook
@@ -596,13 +593,6 @@ public:
   }
 #endif
 
-  // Fill a style struct with data
-  nsresult GetStyle(nsStyleStructID aSID, const nsStyleStruct** aStruct) const {
-    NS_ASSERTION(mStyleContext, "No style context found!");
-    mStyleContext->GetStyle(aSID, aStruct);
-    return NS_OK;
-  }
-
   // Utility function: more convenient than 2 calls to GetStyleData to get border and padding
   NS_IMETHOD  CalcBorderPadding(nsMargin& aBorderPadding) const = 0;
 
@@ -616,10 +606,10 @@ public:
    * The indicies must be consecutive and implementations MUST return an 
    * NS_ERROR_INVALID_ARG if asked for an index that is out of range.
    */
-  NS_IMETHOD  GetAdditionalStyleContext(PRInt32 aIndex, 
-                                        nsIStyleContext** aStyleContext) const = 0;
-  NS_IMETHOD  SetAdditionalStyleContext(PRInt32 aIndex, 
-                                        nsIStyleContext* aStyleContext) = 0;
+  virtual nsStyleContext* GetAdditionalStyleContext(PRInt32 aIndex) const = 0;
+
+  virtual void SetAdditionalStyleContext(PRInt32 aIndex,
+                                         nsStyleContext* aStyleContext) = 0;
 
   /**
    * Accessor functions for geometric parent
@@ -1239,7 +1229,7 @@ protected:
   // Members
   nsRect           mRect;
   nsIContent*      mContent;
-  nsIStyleContext* mStyleContext;
+  nsStyleContext*  mStyleContext;
   nsIFrame*        mParent;
   nsIFrame*        mNextSibling;  // singly-linked list of frames
   nsFrameState     mState;
@@ -1250,7 +1240,7 @@ private:
 };
 
 // typesafe way to access style data.  See comment in nsStyleStruct.h
-// and also overloaded function in nsIStyleContext.h
+// and also overloaded function in nsStyleContext.h
 template <class T>
 inline void
 GetStyleData(nsIFrame* aFrame, const T** aStyleStruct)
diff --git a/mozilla/layout/base/public/nsIFrameManager.h b/mozilla/layout/base/public/nsIFrameManager.h
index a1182e031d0..81efb4699b8 100644
--- a/mozilla/layout/base/public/nsIFrameManager.h
+++ b/mozilla/layout/base/public/nsIFrameManager.h
@@ -48,7 +48,7 @@ class nsIContent;
 class nsIPresContext;
 class nsIPresShell;
 class nsIStyleSet;
-class nsIStyleContext;
+class nsStyleContext;
 class nsILayoutHistoryState;
 class nsStyleChangeList;
 class nsPlaceholderFrame;
@@ -107,8 +107,9 @@ public:
   NS_IMETHOD ClearPlaceholderFrameMap() = 0;
 
   // Mapping undisplayed content
-  NS_IMETHOD GetUndisplayedContent(nsIContent* aContent, nsIStyleContext** aStyleContext)=0;
-  NS_IMETHOD SetUndisplayedContent(nsIContent* aContent, nsIStyleContext* aStyleContext) = 0;
+  virtual nsStyleContext* GetUndisplayedContent(nsIContent* aContent) = 0;
+  virtual void SetUndisplayedContent(nsIContent* aContent,
+                                     nsStyleContext* aStyleContext) = 0;
   NS_IMETHOD ClearUndisplayedContentIn(nsIContent* aContent, nsIContent* aParentContent) = 0;
   NS_IMETHOD ClearAllUndisplayedContentIn(nsIContent* aParentContent) = 0;
   NS_IMETHOD ClearUndisplayedContentMap() = 0;
@@ -149,7 +150,7 @@ public:
   // new given parent style context
   NS_IMETHOD ReParentStyleContext(nsIPresContext* aPresContext, 
                                   nsIFrame* aFrame, 
-                                  nsIStyleContext* aNewParentContext) = 0;
+                                  nsStyleContext* aNewParentContext) = 0;
 
   // Re-resolve style contexts for frame tree
   NS_IMETHOD ComputeStyleChangeFor(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/base/public/nsIPresContext.h b/mozilla/layout/base/public/nsIPresContext.h
index 98cbb80d9ec..05af526ea97 100644
--- a/mozilla/layout/base/public/nsIPresContext.h
+++ b/mozilla/layout/base/public/nsIPresContext.h
@@ -43,6 +43,7 @@
 #include "nsAString.h"
 #include "nsIRequest.h"
 #include "nsCompatibility.h"
+#include "nsCOMPtr.h"
 #ifdef IBMBIDI
 class nsBidiPresUtils;
 #endif // IBMBIDI
@@ -61,7 +62,7 @@ class nsIImage;
 class nsILinkHandler;
 class nsIPresShell;
 class nsIPref;
-class nsIStyleContext;
+class nsStyleContext;
 class nsIAtom;
 class nsString;
 class nsIEventStateManager;
@@ -192,9 +193,9 @@ public:
    * Resolve style for the given piece of content that will be a child
    * of the aParentContext. Don't use this for pseudo frames.
    */
-  NS_IMETHOD ResolveStyleContextFor(nsIContent* aContent,
-                                    nsIStyleContext* aParentContext,
-                                    nsIStyleContext** aResult) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleContextFor(nsIContent* aContent,
+                         nsStyleContext* aParentContext) = 0;
 
   /**
    * Resolve the given style struct for a content node.
@@ -221,19 +222,19 @@ public:
    * represents everything except the first letter.)
    *
    */
-  NS_IMETHOD ResolveStyleContextForNonElement(
-                                    nsIStyleContext* aParentContext,
-                                    nsIStyleContext** aResult) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleContextForNonElement(nsStyleContext* aParentContext) = 0;
 
   /**
    * Resolve style for a pseudo frame within the given aParentContent & aParentContext.
    * The tag should be lowercase and inclue the colon.
    * ie: NS_NewAtom(":first-line");
    */
-  NS_IMETHOD ResolvePseudoStyleContextFor(nsIContent* aParentContent,
-                                          nsIAtom* aPseudoTag,
-                                          nsIStyleContext* aParentContext,
-                                          nsIStyleContext** aResult) = 0;
+
+  virtual already_AddRefed<nsStyleContext>
+  ResolvePseudoStyleContextFor(nsIContent* aParentContent,
+                               nsIAtom* aPseudoTag,
+                               nsStyleContext* aParentContext) = 0;
 
   /**
    * Resolve style for a pseudo frame within the given aParentContent & aParentContext.
@@ -243,11 +244,11 @@ public:
    * Instead of matching solely on aPseudoTag, a comparator function can be
    * passed in to test.
    */
-  NS_IMETHOD ResolvePseudoStyleWithComparator(nsIContent* aParentContent,
-                                              nsIAtom* aPseudoTag,
-                                              nsIStyleContext* aParentContext,
-                                              nsICSSPseudoComparator* aComparator,
-                                              nsIStyleContext** aResult) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ResolvePseudoStyleWithComparator(nsIContent* aParentContent,
+                                   nsIAtom* aPseudoTag,
+                                   nsStyleContext* aParentContext,
+                                   nsICSSPseudoComparator* aComparator) = 0;
 
   /**
    * Probe style for a pseudo frame within the given aParentContent & aParentContext.
@@ -255,17 +256,17 @@ public:
    * The tag should be lowercase and inclue the colon.
    * ie: NS_NewAtom(":first-line");
    */
-  NS_IMETHOD ProbePseudoStyleContextFor(nsIContent* aParentContent,
-                                        nsIAtom* aPseudoTag,
-                                        nsIStyleContext* aParentContext,
-                                        nsIStyleContext** aResult) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ProbePseudoStyleContextFor(nsIContent* aParentContent,
+                             nsIAtom* aPseudoTag,
+                             nsStyleContext* aParentContext) = 0;
 
   /** 
    * For a given frame tree, get a new style context that is the equivalent
    * but within a new parent
    */
   NS_IMETHOD ReParentStyleContext(nsIFrame* aFrame, 
-                                  nsIStyleContext* aNewParentContext) = 0;
+                                  nsStyleContext* aNewParentContext) = 0;
 
 
   NS_IMETHOD AllocateFromShell(size_t aSize, void** aResult) = 0;
diff --git a/mozilla/layout/base/public/nsIPresShell.h b/mozilla/layout/base/public/nsIPresShell.h
index b0ed3065a8c..8e18a9ce5fb 100644
--- a/mozilla/layout/base/public/nsIPresShell.h
+++ b/mozilla/layout/base/public/nsIPresShell.h
@@ -59,7 +59,7 @@ class nsString;
 class nsAString;
 class nsStringArray;
 class nsICaret;
-class nsIStyleContext;
+class nsStyleContext;
 class nsIFrameSelection;
 class nsIFrameManager;
 class nsILayoutHistoryState;
@@ -258,13 +258,6 @@ public:
   NS_IMETHOD GetPrimaryFrameFor(nsIContent* aContent,
                                 nsIFrame**  aPrimaryFrame) const = 0;
 
-  /** Returns the style context associated with the frame.
-    * Used by code outside of layout that can't use nsIFrame methods to get
-    * the style context directly.
-    */
-  NS_IMETHOD GetStyleContextFor(nsIFrame*         aFrame,
-                                nsIStyleContext** aStyleContext) const = 0;
-
   /**
    * Returns a layout object associated with the primary frame for the content object.
    *
diff --git a/mozilla/layout/base/public/nsIStyleContext.h b/mozilla/layout/base/public/nsIStyleContext.h
deleted file mode 100644
index cb22178abc7..00000000000
--- a/mozilla/layout/base/public/nsIStyleContext.h
+++ /dev/null
@@ -1,150 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* ***** BEGIN LICENSE BLOCK *****
- * Version: NPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Netscape Public License
- * Version 1.1 (the "License"); you may not use this file except in
- * compliance with the License. You may obtain a copy of the License at
- * http://www.mozilla.org/NPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is mozilla.org code.
- *
- * The Initial Developer of the Original Code is 
- * Netscape Communications Corporation.
- * Portions created by the Initial Developer are Copyright (C) 1998
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either the GNU General Public License Version 2 or later (the "GPL"), or 
- * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the NPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the NPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
-#ifndef nsIStyleContext_h___
-#define nsIStyleContext_h___
-
-#include "nsISupports.h"
-#include "nsColor.h"
-#include "nsCoord.h"
-#include "nsMargin.h"
-#include "nsRect.h"
-#include "nsFont.h"
-#include "nsVoidArray.h"
-#include "nsStyleCoord.h"
-#include "nsStyleStruct.h"
-#include "nsStyleConsts.h"
-#include "nsChangeHint.h"
-#include "nsCOMPtr.h"
-#include "nsILanguageAtom.h"
-
-class nsISizeOfHandler;
-
-class nsIFrame;
-class nsIStyleSet;
-class nsIPresContext;
-class nsISupportsArray;
-class nsIStyleContext;
-class nsRuleNode;
-
-//----------------------------------------------------------------------
-
-#define NS_ISTYLECONTEXT_IID   \
- { 0x26a4d970, 0xa342, 0x11d1, \
-   {0x89, 0x74, 0x00, 0x60, 0x08, 0x91, 0x1b, 0x81} }
-
-class nsIStyleContext : public nsISupports {
-public:
-  NS_DEFINE_STATIC_IID_ACCESSOR(NS_ISTYLECONTEXT_IID)
-
-  virtual PRBool    Equals(const nsIStyleContext* aOther) const = 0;
-  
-  virtual already_AddRefed<nsIStyleContext> GetParent(void) const = 0;
-  NS_IMETHOD GetFirstChild(nsIStyleContext** aContext)=0;
-
-  NS_IMETHOD GetPseudoType(nsIAtom*& aPseudoTag) const = 0;
-
-  NS_IMETHOD FindChildWithRules(const nsIAtom* aPseudoTag, 
-                                nsRuleNode* aRules,
-                                nsIStyleContext*& aResult) = 0;
-
-  virtual PRBool HasTextDecorations()=0;
-
-   
-  NS_IMETHOD GetBorderPaddingFor(nsStyleBorderPadding& aBorderPadding)=0;
-
-  // This method computes the effective difference between two contexts that are both at the
-  // same position in the style context tree.  The |this| parameter must always
-  // be the old context.  This method will only peek at style data on the old
-  // context, and will not instantiate new data in order to compute a difference.
-  // That is why the old context must always be used (since the new context will
-  // have no data on it yet) for determining the actual difference.
-  NS_IMETHOD CalcStyleDifference(nsIStyleContext* aOther, nsChangeHint& aHint) = 0;
-
-  NS_IMETHOD GetRuleNode(nsRuleNode** aResult)=0;
-  NS_IMETHOD AddStyleBit(const PRUint32& aBit)=0;
-  NS_IMETHOD GetStyleBits(PRUint32* aBits)=0;
-
-#ifdef DEBUG
-  // debugging
-  virtual void List(FILE* out, PRInt32 aIndent) = 0;
-  virtual void SizeOf(nsISizeOfHandler *aSizeOfHandler, PRUint32 &aSize) = 0;
-  virtual void DumpRegressionData(nsIPresContext* aPresContext, FILE* out, PRInt32 aIndent)=0;
-#endif
-
-  // XXXdwh Make this function private.  It should not be possible to call this
-  // function from layout.
-  // Fill a style struct with data.  
-  NS_IMETHOD SetStyle(nsStyleStructID aSID, nsStyleStruct* aStruct) = 0;
-  
-  // Get the data for a style struct.
-  NS_IMETHOD GetStyle(nsStyleStructID aSID, const nsStyleStruct** aStruct) = 0;
-
-  virtual const nsStyleStruct* GetStyleData(nsStyleStructID aSID) = 0;
-
-  // Avoid using this method at all costs.  It defeats sharing of style data, forcing the context
-  // to have its own unique copy.  At the moment the only supported structs are text, background, and
-  // display.  Don't add support for new structs or use this method without careful consideration! -dwh
-  virtual nsStyleStruct* GetUniqueStyleData(nsIPresContext* aPresContext, const nsStyleStructID& aSID) = 0;
-
-  // Used only for inline style.
-  virtual nsresult ClearCachedDataForRule(nsIStyleRule* aRule) = 0;
-
-  // Used to clear away the style data for a given style context if it matches the specified |aRule|.
-  // If |aRule| is null, then the style data is always blown away.
-  virtual nsresult ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule) = 0;
-};
-
-
-// this is private to nsStyleSet, don't call it
-extern NS_EXPORT nsresult
-  NS_NewStyleContext(nsIStyleContext** aInstancePtrResult,
-                     nsIStyleContext* aParentContext,
-                     nsIAtom* aPseudoType,
-                     nsRuleNode* aRuleNode,
-                     nsIPresContext* aPresContext);
-
-// typesafe way to access style data.  See nsStyleStruct.h and also
-// overloaded function in nsIFrame.h.
-template <class T>
-inline void
-GetStyleData(nsIStyleContext* aStyleContext, const T** aStyleStruct)
-{
-    *aStyleStruct = NS_STATIC_CAST(const T*,
-                         aStyleContext->GetStyleData(NS_GET_STYLESTRUCTID(T)));
-}
-
-#endif /* nsIStyleContext_h___ */
diff --git a/mozilla/layout/base/public/nsIStyleSet.h b/mozilla/layout/base/public/nsIStyleSet.h
index 75e751e43d5..37226cecf00 100644
--- a/mozilla/layout/base/public/nsIStyleSet.h
+++ b/mozilla/layout/base/public/nsIStyleSet.h
@@ -41,11 +41,12 @@
 #include <stdio.h>
 #include "nsISupports.h"
 #include "nsChangeHint.h"
+#include "nsCOMPtr.h"
 
 class nsIAtom;
 class nsIStyleRule;
 class nsIStyleSheet;
-class nsIStyleContext;
+class nsStyleContext;
 class nsIStyleRuleSupplier;
 class nsIStyleFrameConstruction;
 class nsIPresContext;
@@ -141,7 +142,7 @@ public:
   // |aContext| provides an additional hint that a specific style context has changed, and
   // that the entire rule tree need not be searched for occurrences of |aRule|.  It is
   // only specified in the inline style case, i.e., when the inline style attribute changes.
-  virtual nsresult ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule, nsIStyleContext* aContext) = 0;
+  virtual nsresult ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule, nsStyleContext* aContext) = 0;
 
   // enable / disable the Quirk style sheet: 
   // returns NS_FAILURE if none is found, otherwise NS_OK
@@ -150,10 +151,11 @@ public:
   
   NS_IMETHOD NotifyStyleSheetStateChanged(PRBool aApplicable) = 0;
 
-  // get a style context for a non-pseudo frame
-  virtual nsIStyleContext* ResolveStyleFor(nsIPresContext* aPresContext,
-                                           nsIContent* aContent,
-                                           nsIStyleContext* aParentContext) = 0;
+  // get a style context for a non-pseudo frame.
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleFor(nsIPresContext* aPresContext,
+                  nsIContent* aContent,
+                  nsStyleContext* aParentContext) = 0;
 
   // Get a style context for a non-element (which no rules will match).
   // Eventually, this should go away and we shouldn't even create style
@@ -165,34 +167,36 @@ public:
   // it once to create a style context for the nsFirstLetterFrame that
   // represents everything except the first letter.)
   //
-  virtual nsIStyleContext* ResolveStyleForNonElement(
-                                           nsIPresContext* aPresContext,
-                                           nsIStyleContext* aParentContext) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleForNonElement(nsIPresContext* aPresContext,
+                            nsStyleContext* aParentContext) = 0;
 
   // get a style context for a pseudo-element (i.e.,
   // |aPseudoTag == nsCOMPtr<nsIAtom>(do_GetAtom(":first-line"))|;
-  virtual nsIStyleContext* ResolvePseudoStyleFor(nsIPresContext* aPresContext,
-                                                 nsIContent* aParentContent,
-                                                 nsIAtom* aPseudoTag,
-                                                 nsIStyleContext* aParentContext,
-                                                 nsICSSPseudoComparator* aComparator = nsnull) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ResolvePseudoStyleFor(nsIPresContext* aPresContext,
+                        nsIContent* aParentContent,
+                        nsIAtom* aPseudoTag,
+                        nsStyleContext* aParentContext,
+                        nsICSSPseudoComparator* aComparator = nsnull) = 0;
 
   // This funtions just like ResolvePseudoStyleFor except that it will
   // return nsnull if there are no explicit style rules for that
-  // pseudo element
-  virtual nsIStyleContext* ProbePseudoStyleFor(nsIPresContext* aPresContext,
-                                               nsIContent* aParentContent,
-                                               nsIAtom* aPseudoTag,
-                                               nsIStyleContext* aParentContext) = 0;
+  // pseudo element.
+  virtual already_AddRefed<nsStyleContext>
+  ProbePseudoStyleFor(nsIPresContext* aPresContext,
+                      nsIContent* aParentContent,
+                      nsIAtom* aPseudoTag,
+                      nsStyleContext* aParentContext) = 0;
 
   NS_IMETHOD Shutdown()=0;
 
   // Get a new style context that lives in a different parent
   // The new context will be the same as the old if the new parent == the old parent
-  NS_IMETHOD  ReParentStyleContext(nsIPresContext* aPresContext,
-                                   nsIStyleContext* aStyleContext, 
-                                   nsIStyleContext* aNewParentContext,
-                                   nsIStyleContext** aNewStyleContext) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ReParentStyleContext(nsIPresContext* aPresContext,
+                       nsStyleContext* aStyleContext, 
+                       nsStyleContext* aNewParentContext) = 0;
 
   // Test if style is dependent on content state
   NS_IMETHOD  HasStateDependentStyle(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/base/public/nsPresContext.h b/mozilla/layout/base/public/nsPresContext.h
index 98cbb80d9ec..05af526ea97 100644
--- a/mozilla/layout/base/public/nsPresContext.h
+++ b/mozilla/layout/base/public/nsPresContext.h
@@ -43,6 +43,7 @@
 #include "nsAString.h"
 #include "nsIRequest.h"
 #include "nsCompatibility.h"
+#include "nsCOMPtr.h"
 #ifdef IBMBIDI
 class nsBidiPresUtils;
 #endif // IBMBIDI
@@ -61,7 +62,7 @@ class nsIImage;
 class nsILinkHandler;
 class nsIPresShell;
 class nsIPref;
-class nsIStyleContext;
+class nsStyleContext;
 class nsIAtom;
 class nsString;
 class nsIEventStateManager;
@@ -192,9 +193,9 @@ public:
    * Resolve style for the given piece of content that will be a child
    * of the aParentContext. Don't use this for pseudo frames.
    */
-  NS_IMETHOD ResolveStyleContextFor(nsIContent* aContent,
-                                    nsIStyleContext* aParentContext,
-                                    nsIStyleContext** aResult) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleContextFor(nsIContent* aContent,
+                         nsStyleContext* aParentContext) = 0;
 
   /**
    * Resolve the given style struct for a content node.
@@ -221,19 +222,19 @@ public:
    * represents everything except the first letter.)
    *
    */
-  NS_IMETHOD ResolveStyleContextForNonElement(
-                                    nsIStyleContext* aParentContext,
-                                    nsIStyleContext** aResult) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleContextForNonElement(nsStyleContext* aParentContext) = 0;
 
   /**
    * Resolve style for a pseudo frame within the given aParentContent & aParentContext.
    * The tag should be lowercase and inclue the colon.
    * ie: NS_NewAtom(":first-line");
    */
-  NS_IMETHOD ResolvePseudoStyleContextFor(nsIContent* aParentContent,
-                                          nsIAtom* aPseudoTag,
-                                          nsIStyleContext* aParentContext,
-                                          nsIStyleContext** aResult) = 0;
+
+  virtual already_AddRefed<nsStyleContext>
+  ResolvePseudoStyleContextFor(nsIContent* aParentContent,
+                               nsIAtom* aPseudoTag,
+                               nsStyleContext* aParentContext) = 0;
 
   /**
    * Resolve style for a pseudo frame within the given aParentContent & aParentContext.
@@ -243,11 +244,11 @@ public:
    * Instead of matching solely on aPseudoTag, a comparator function can be
    * passed in to test.
    */
-  NS_IMETHOD ResolvePseudoStyleWithComparator(nsIContent* aParentContent,
-                                              nsIAtom* aPseudoTag,
-                                              nsIStyleContext* aParentContext,
-                                              nsICSSPseudoComparator* aComparator,
-                                              nsIStyleContext** aResult) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ResolvePseudoStyleWithComparator(nsIContent* aParentContent,
+                                   nsIAtom* aPseudoTag,
+                                   nsStyleContext* aParentContext,
+                                   nsICSSPseudoComparator* aComparator) = 0;
 
   /**
    * Probe style for a pseudo frame within the given aParentContent & aParentContext.
@@ -255,17 +256,17 @@ public:
    * The tag should be lowercase and inclue the colon.
    * ie: NS_NewAtom(":first-line");
    */
-  NS_IMETHOD ProbePseudoStyleContextFor(nsIContent* aParentContent,
-                                        nsIAtom* aPseudoTag,
-                                        nsIStyleContext* aParentContext,
-                                        nsIStyleContext** aResult) = 0;
+  virtual already_AddRefed<nsStyleContext>
+  ProbePseudoStyleContextFor(nsIContent* aParentContent,
+                             nsIAtom* aPseudoTag,
+                             nsStyleContext* aParentContext) = 0;
 
   /** 
    * For a given frame tree, get a new style context that is the equivalent
    * but within a new parent
    */
   NS_IMETHOD ReParentStyleContext(nsIFrame* aFrame, 
-                                  nsIStyleContext* aNewParentContext) = 0;
+                                  nsStyleContext* aNewParentContext) = 0;
 
 
   NS_IMETHOD AllocateFromShell(size_t aSize, void** aResult) = 0;
diff --git a/mozilla/layout/base/public/nsStyleConsts.h b/mozilla/layout/base/public/nsStyleConsts.h
index af52e199fab..966fb4abe93 100644
--- a/mozilla/layout/base/public/nsStyleConsts.h
+++ b/mozilla/layout/base/public/nsStyleConsts.h
@@ -39,7 +39,7 @@
 
 #include "nsFont.h"
 
-// XXX fold this into nsIStyleContext and group by nsStyleXXX struct
+// XXX fold this into nsStyleContext and group by nsStyleXXX struct
 
 // Indicies into border/padding/margin arrays
 #define NS_SIDE_TOP     0
diff --git a/mozilla/layout/base/src/nsBidiPresUtils.cpp b/mozilla/layout/base/src/nsBidiPresUtils.cpp
index ed37179c4eb..0e8bd493d5f 100644
--- a/mozilla/layout/base/src/nsBidiPresUtils.cpp
+++ b/mozilla/layout/base/src/nsBidiPresUtils.cpp
@@ -126,14 +126,13 @@ CreateBidiContinuation(nsIPresContext* aPresContext,
   if (!(*aNewFrame) ) {
     return NS_ERROR_OUT_OF_MEMORY;
   }
-  nsCOMPtr<nsIStyleContext> styleContext;
-  aFrame->GetStyleContext(getter_AddRefs(styleContext) );
+  nsStyleContext* styleContext = aFrame->GetStyleContext();
 
-  NS_ASSERTION(presShell, "Frame has no styleContext in nsBidiPresUtils::CreateBidiContinuation");
+  NS_ASSERTION(styleContext, "Frame has no styleContext in nsBidiPresUtils::CreateBidiContinuation");
   
   aFrame->GetParent(&parent);
 
-  NS_ASSERTION(presShell, "Couldn't get frame parent in nsBidiPresUtils::CreateBidiContinuation");
+  NS_ASSERTION(parent, "Couldn't get frame parent in nsBidiPresUtils::CreateBidiContinuation");
 
   (*aNewFrame)->Init(aPresContext, aContent, parent, styleContext, nsnull);
 
diff --git a/mozilla/layout/base/src/nsImageLoader.cpp b/mozilla/layout/base/src/nsImageLoader.cpp
index 555f0cae0d7..a298b098fde 100644
--- a/mozilla/layout/base/src/nsImageLoader.cpp
+++ b/mozilla/layout/base/src/nsImageLoader.cpp
@@ -41,7 +41,7 @@
 
 #include "nsIViewManager.h"
 
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 
 NS_IMPL_ISUPPORTS2(nsImageLoader, imgIDecoderObserver, imgIContainerObserver)
 
@@ -240,8 +240,8 @@ nsImageLoader::RedrawDirtyFrame(const nsRect* aDamageRect)
   // Invalidate the entire frame only if the frame has a tiled background
   // image, otherwise just invalidate the intersection of the frame's bounds
   // with the damaged rect.
-  nsCOMPtr<nsIStyleContext> styleContext;
-  mFrame->GetStyleContext(getter_AddRefs(styleContext));
+  nsStyleContext* styleContext;
+  mFrame->GetStyleContext(&styleContext);
   const nsStyleBackground* bg = (const nsStyleBackground*)styleContext->GetStyleData(eStyleStruct_Background);
 
   if ((bg->mBackgroundFlags & NS_STYLE_BG_IMAGE_NONE) ||
diff --git a/mozilla/layout/base/src/nsPresContext.cpp b/mozilla/layout/base/src/nsPresContext.cpp
index 127f8737c3f..daa34f750ff 100644
--- a/mozilla/layout/base/src/nsPresContext.cpp
+++ b/mozilla/layout/base/src/nsPresContext.cpp
@@ -48,7 +48,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIURL.h"
 #include "nsIDocument.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsLayoutAtoms.h"
 #include "nsILookAndFeel.h"
 #include "nsWidgetsCID.h"
@@ -69,6 +69,7 @@
 #include "nsContentPolicyUtils.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsIDOMDocument.h"
+#include "nsAutoPtr.h"
 #ifdef IBMBIDI
 #include "nsBidiPresUtils.h"
 #endif // IBMBIDI
@@ -934,26 +935,18 @@ nsPresContext::GetBaseURL(nsIURI** aResult)
   return NS_OK;
 }
 
-NS_IMETHODIMP
+already_AddRefed<nsStyleContext>
 nsPresContext::ResolveStyleContextFor(nsIContent* aContent,
-                                      nsIStyleContext* aParentContext,
-                                      nsIStyleContext** aResult)
+                                      nsStyleContext* aParentContext)
 {
-  NS_PRECONDITION(aResult, "null out param");
-
-  nsIStyleContext* result = nsnull;
   nsCOMPtr<nsIStyleSet> set;
   nsresult rv = mShell->GetStyleSet(getter_AddRefs(set));
-  if (NS_SUCCEEDED(rv)) {
-    if (set) {
-      result = set->ResolveStyleFor(this, aContent, aParentContext);
-      if (nsnull == result) {
-        rv = NS_ERROR_OUT_OF_MEMORY;
-      }
-    }
+  if (NS_SUCCEEDED(rv) && set) {
+    // return the addref'd style context
+    return set->ResolveStyleFor(this, aContent, aParentContext);
   }
-  *aResult = result;
-  return rv;
+
+  return nsnull;
 }
 
 NS_IMETHODIMP
@@ -961,92 +954,71 @@ nsPresContext::ResolveStyleContextAndGetStyleData(nsIContent* aContent,
                                                   int aSID,
                                                   const nsStyleStruct*& aStyleStruct)
 {
-  nsCOMPtr<nsIStyleContext> sc;
-  nsresult rv = ResolveStyleContextFor(aContent, nsnull, getter_AddRefs(sc));
-  NS_ENSURE_SUCCESS(rv, rv);
+  nsRefPtr<nsStyleContext> sc = ResolveStyleContextFor(aContent, nsnull);
+  if (!sc) return NS_ERROR_FAILURE;
 
   aStyleStruct = sc->GetStyleData((nsStyleStructID) aSID);
   return aStyleStruct ? NS_OK : NS_ERROR_FAILURE;
 }
 
-NS_IMETHODIMP
-nsPresContext::ResolveStyleContextForNonElement(
-                                      nsIStyleContext* aParentContext,
-                                      nsIStyleContext** aResult)
+already_AddRefed<nsStyleContext>
+nsPresContext::ResolveStyleContextForNonElement(nsStyleContext* aParentContext)
 {
-  NS_PRECONDITION(aResult, "null out param");
-
-  nsIStyleContext* result = nsnull;
   nsCOMPtr<nsIStyleSet> set;
   nsresult rv = mShell->GetStyleSet(getter_AddRefs(set));
   if (NS_SUCCEEDED(rv) && set) {
-    result = set->ResolveStyleForNonElement(this, aParentContext);
-    if (!result)
-      rv = NS_ERROR_OUT_OF_MEMORY;
+    // return addrefed style context
+    return set->ResolveStyleForNonElement(this, aParentContext);
   }
-  *aResult = result;
-  return rv;
+
+  return nsnull;
 }
 
-NS_IMETHODIMP
+already_AddRefed<nsStyleContext>
 nsPresContext::ResolvePseudoStyleContextFor(nsIContent* aParentContent,
                                             nsIAtom* aPseudoTag,
-                                            nsIStyleContext* aParentContext,
-                                            nsIStyleContext** aResult)
+                                            nsStyleContext* aParentContext)
 {
-  return ResolvePseudoStyleWithComparator(aParentContent, aPseudoTag, aParentContext,
-                                          nsnull, aResult);
+  return ResolvePseudoStyleWithComparator(aParentContent, aPseudoTag,
+                                          aParentContext, nsnull);
 }
 
-NS_IMETHODIMP
+already_AddRefed<nsStyleContext>
 nsPresContext::ResolvePseudoStyleWithComparator(nsIContent* aParentContent,
                                                 nsIAtom* aPseudoTag,
-                                                nsIStyleContext* aParentContext,
-                                                nsICSSPseudoComparator* aComparator,
-                                                nsIStyleContext** aResult)
+                                                nsStyleContext* aParentContext,
+                                                nsICSSPseudoComparator* aComparator)
 {
-  NS_PRECONDITION(aResult, "null out param");
-
-  nsIStyleContext* result = nsnull;
   nsCOMPtr<nsIStyleSet> set;
   nsresult rv = mShell->GetStyleSet(getter_AddRefs(set));
-  if (NS_SUCCEEDED(rv)) {
-    if (set) {
-      result = set->ResolvePseudoStyleFor(this, aParentContent, aPseudoTag,
-                                          aParentContext, aComparator);
-      if (nsnull == result) {
-        rv = NS_ERROR_OUT_OF_MEMORY;
-      }
-    }
+  if (NS_SUCCEEDED(rv) && set) {
+    // return addrefed style context
+    return set->ResolvePseudoStyleFor(this, aParentContent, aPseudoTag,
+                                      aParentContext, aComparator);
   }
-  *aResult = result;
-  return rv;
+
+  return nsnull;
 }
 
-NS_IMETHODIMP
+already_AddRefed<nsStyleContext>
 nsPresContext::ProbePseudoStyleContextFor(nsIContent* aParentContent,
                                           nsIAtom* aPseudoTag,
-                                          nsIStyleContext* aParentContext,
-                                          nsIStyleContext** aResult)
+                                          nsStyleContext* aParentContext)
 {
-  NS_PRECONDITION(aResult, "null out param");
-
-  nsIStyleContext* result = nsnull;
   nsCOMPtr<nsIStyleSet> set;
   nsresult rv = mShell->GetStyleSet(getter_AddRefs(set));
-  if (NS_SUCCEEDED(rv)) {
-    if (set) {
-      result = set->ProbePseudoStyleFor(this, aParentContent, aPseudoTag,
-                                        aParentContext);
-    }
+  if (NS_SUCCEEDED(rv) && set) {
+    // return addrefed style context
+    return set->ProbePseudoStyleFor(this, aParentContent, aPseudoTag,
+                                    aParentContext);
   }
-  *aResult = result;
-  return rv;
+
+  return nsnull;
 }
 
 NS_IMETHODIMP
 nsPresContext::ReParentStyleContext(nsIFrame* aFrame, 
-                                    nsIStyleContext* aNewParentContext)
+                                    nsStyleContext* aNewParentContext)
 {
   NS_PRECONDITION(aFrame, "null ptr");
   if (! aFrame) {
diff --git a/mozilla/layout/base/src/nsPresContext.h b/mozilla/layout/base/src/nsPresContext.h
index 8d364829865..0f2461430d6 100644
--- a/mozilla/layout/base/src/nsPresContext.h
+++ b/mozilla/layout/base/src/nsPresContext.h
@@ -84,29 +84,35 @@ public:
   NS_IMETHOD GetBaseURL(nsIURI** aURLResult);
   NS_IMETHOD GetMedium(nsIAtom** aMediumResult) = 0;
   NS_IMETHOD ClearStyleDataAndReflow(void);
-  NS_IMETHOD ResolveStyleContextFor(nsIContent* aContent,
-                                    nsIStyleContext* aParentContext,
-                                    nsIStyleContext** aResult);
+
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleContextFor(nsIContent* aContent, nsStyleContext* aParentContext);
+
   NS_IMETHOD ResolveStyleContextAndGetStyleData(nsIContent* aContent,
                                                 int aSID,
                                                 const nsStyleStruct*& aStyleStruct);
-  NS_IMETHOD ResolveStyleContextForNonElement(nsIStyleContext* aParentContext,
-                                              nsIStyleContext** aResult);
-  NS_IMETHOD ResolvePseudoStyleContextFor(nsIContent* aParentContent,
-                                          nsIAtom* aPseudoTag,
-                                          nsIStyleContext* aParentContext,
-                                          nsIStyleContext** aResult);
-  NS_IMETHOD ResolvePseudoStyleWithComparator(nsIContent* aParentContent,
-                                          nsIAtom* aPseudoTag,
-                                          nsIStyleContext* aParentContext,
-                                          nsICSSPseudoComparator* aComparator,
-                                          nsIStyleContext** aResult);
-  NS_IMETHOD ProbePseudoStyleContextFor(nsIContent* aParentContent,
-                                        nsIAtom* aPseudoTag,
-                                        nsIStyleContext* aParentContext,
-                                        nsIStyleContext** aResult);
+
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleContextForNonElement(nsStyleContext* aParentContext);
+
+  virtual already_AddRefed<nsStyleContext>
+  ResolvePseudoStyleContextFor(nsIContent* aParentContent,
+                               nsIAtom* aPseudoTag,
+                               nsStyleContext* aParentContext);
+
+  virtual already_AddRefed<nsStyleContext>
+  ResolvePseudoStyleWithComparator(nsIContent* aParentContent,
+                                   nsIAtom* aPseudoTag,
+                                   nsStyleContext* aParentContext,
+                                   nsICSSPseudoComparator* aComparator);
+
+  virtual already_AddRefed<nsStyleContext>
+  ProbePseudoStyleContextFor(nsIContent* aParentContent,
+                             nsIAtom* aPseudoTag,
+                             nsStyleContext* aParentContext);
+
   NS_IMETHOD ReParentStyleContext(nsIFrame* aFrame, 
-                                  nsIStyleContext* aNewParentContext);
+                                  nsStyleContext* aNewParentContext);
   NS_IMETHOD GetMetricsFor(const nsFont& aFont, nsIFontMetrics** aResult);
   NS_IMETHOD AllocateFromShell(size_t aSize, void** aResult);
   NS_IMETHOD FreeToShell(size_t aSize, void* aFreeChunk);
diff --git a/mozilla/layout/forms/nsButtonFrameRenderer.cpp b/mozilla/layout/forms/nsButtonFrameRenderer.cpp
index ac98d993321..51c05b6890a 100644
--- a/mozilla/layout/forms/nsButtonFrameRenderer.cpp
+++ b/mozilla/layout/forms/nsButtonFrameRenderer.cpp
@@ -145,7 +145,7 @@ nsButtonFrameRenderer::PaintOutlineAndFocusBorders(nsIPresContext* aPresContext,
     GetButtonOuterFocusRect(aRect, rect);
 
     const nsStyleBorder* border;
-    ::GetStyleData(NS_STATIC_CAST(nsIStyleContext*,mOuterFocusStyle), &border);
+    ::GetStyleData(mOuterFocusStyle, &border);
     nsCSSRendering::PaintBorder(aPresContext, aRenderingContext, mFrame,
                                 aDirtyRect, rect, *border, mOuterFocusStyle, 0);
   }
@@ -156,7 +156,7 @@ nsButtonFrameRenderer::PaintOutlineAndFocusBorders(nsIPresContext* aPresContext,
     GetButtonInnerFocusRect(aRect, rect);
 
     const nsStyleBorder* border;
-    ::GetStyleData(NS_STATIC_CAST(nsIStyleContext*,mInnerFocusStyle), &border);
+    ::GetStyleData(mInnerFocusStyle, &border);
     nsCSSRendering::PaintBorder(aPresContext, aRenderingContext, mFrame,
                                 aDirtyRect, rect, *border, mInnerFocusStyle, 0);
   }
@@ -174,8 +174,7 @@ nsButtonFrameRenderer::PaintBorderAndBackground(nsIPresContext* aPresContext,
   nsRect buttonRect;
   GetButtonRect(aRect, buttonRect);
 
-  nsCOMPtr<nsIStyleContext> context;
-  mFrame->GetStyleContext(getter_AddRefs(context));
+  nsStyleContext* context = mFrame->GetStyleContext();
 
   const nsStyleBorder* border =
     (const nsStyleBorder*)context->GetStyleData(eStyleStruct_Border);
@@ -247,8 +246,7 @@ nsButtonFrameRenderer::GetButtonOuterFocusBorderAndPadding()
 nsMargin
 nsButtonFrameRenderer::GetButtonBorderAndPadding()
 {
-  nsCOMPtr<nsIStyleContext> context;
-  mFrame->GetStyleContext(getter_AddRefs(context));
+  nsStyleContext* context = mFrame->GetStyleContext();
 
   nsMargin innerFocusBorderAndPadding(0,0,0,0);
   nsStyleBorderPadding  bPad;
@@ -324,52 +322,38 @@ nsButtonFrameRenderer::ReResolveStyles(nsIPresContext* aPresContext)
   // get all the styles
   nsCOMPtr<nsIContent> content;
   mFrame->GetContent(getter_AddRefs(content));
-  nsCOMPtr<nsIStyleContext> context;
-  mFrame->GetStyleContext(getter_AddRefs(context));
+  nsStyleContext* context = mFrame->GetStyleContext();
 
 
   // style for the inner such as a dotted line (Windows)
-  aPresContext->ProbePseudoStyleContextFor(content, nsCSSPseudoElements::mozFocusInner, context,
-                                          getter_AddRefs(mInnerFocusStyle));
+  mInnerFocusStyle = aPresContext->ProbePseudoStyleContextFor(content,
+                                                              nsCSSPseudoElements::mozFocusInner,
+                                                              context);
 
   // style for outer focus like a ridged border (MAC).
-  aPresContext->ProbePseudoStyleContextFor(content, nsCSSPseudoElements::mozFocusOuter, context,
-                                          getter_AddRefs(mOuterFocusStyle));
+  mOuterFocusStyle = aPresContext->ProbePseudoStyleContextFor(content,
+                                                              nsCSSPseudoElements::mozFocusOuter,
+                                                              context);
 
 }
 
-nsresult 
-nsButtonFrameRenderer::GetStyleContext(PRInt32 aIndex, nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsButtonFrameRenderer::GetStyleContext(PRInt32 aIndex) const
 {
-  NS_PRECONDITION(nsnull != aStyleContext, "null OUT parameter pointer");
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
-  *aStyleContext = nsnull;
   switch (aIndex) {
-
   case NS_BUTTON_RENDERER_FOCUS_INNER_CONTEXT_INDEX:
-    *aStyleContext = mInnerFocusStyle;
-    NS_IF_ADDREF(*aStyleContext);
-    break;
+    return mInnerFocusStyle;
   case NS_BUTTON_RENDERER_FOCUS_OUTER_CONTEXT_INDEX:
-    *aStyleContext = mOuterFocusStyle;
-    NS_IF_ADDREF(*aStyleContext);
-    break;
+    return mOuterFocusStyle;
   default:
-    return NS_ERROR_INVALID_ARG;
+    return nsnull;
   }
-  return NS_OK;
 }
 
-nsresult 
-nsButtonFrameRenderer::SetStyleContext(PRInt32 aIndex, nsIStyleContext* aStyleContext)
+void 
+nsButtonFrameRenderer::SetStyleContext(PRInt32 aIndex, nsStyleContext* aStyleContext)
 {
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
   switch (aIndex) {
- 
   case NS_BUTTON_RENDERER_FOCUS_INNER_CONTEXT_INDEX:
     mInnerFocusStyle = aStyleContext;
     break;
@@ -377,5 +361,4 @@ nsButtonFrameRenderer::SetStyleContext(PRInt32 aIndex, nsIStyleContext* aStyleCo
     mOuterFocusStyle = aStyleContext;
     break;
   }
-  return NS_OK;
 }
diff --git a/mozilla/layout/forms/nsButtonFrameRenderer.h b/mozilla/layout/forms/nsButtonFrameRenderer.h
index a5878958bfc..3e605c0139b 100644
--- a/mozilla/layout/forms/nsButtonFrameRenderer.h
+++ b/mozilla/layout/forms/nsButtonFrameRenderer.h
@@ -44,7 +44,7 @@
 #define nsButtonFrameRenderer_h___
 
 #include "nsCoord.h"
-#include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
 #include "nsFrame.h"
 
 class nsStyleChangeList;
@@ -98,8 +98,8 @@ public:
   virtual nsMargin GetFullButtonBorderAndPadding();
   virtual nsMargin GetAddedButtonBorderAndPadding();
 
-  virtual nsresult GetStyleContext(PRInt32 aIndex, nsIStyleContext** aStyleContext) const;
-  virtual nsresult SetStyleContext(PRInt32 aIndex, nsIStyleContext* aStyleContext);
+  virtual nsStyleContext* GetStyleContext(PRInt32 aIndex) const;
+  virtual void SetStyleContext(PRInt32 aIndex, nsStyleContext* aStyleContext);
 	virtual void ReResolveStyles(nsIPresContext* aPresContext);
 
   virtual void Redraw(nsIPresContext* aPresContext);
@@ -111,9 +111,9 @@ protected:
 private:
 
 	// cached styles for focus and outline.
-	nsCOMPtr<nsIStyleContext> mBorderStyle;
-	nsCOMPtr<nsIStyleContext> mInnerFocusStyle;
-	nsCOMPtr<nsIStyleContext> mOuterFocusStyle;
+  nsRefPtr<nsStyleContext> mBorderStyle;
+  nsRefPtr<nsStyleContext> mInnerFocusStyle;
+  nsRefPtr<nsStyleContext> mOuterFocusStyle;
 
 	nsFrame* mFrame;
 
diff --git a/mozilla/layout/forms/nsComboboxControlFrame.cpp b/mozilla/layout/forms/nsComboboxControlFrame.cpp
index b6802dc3e2d..0d8d6683bca 100644
--- a/mozilla/layout/forms/nsComboboxControlFrame.cpp
+++ b/mozilla/layout/forms/nsComboboxControlFrame.cpp
@@ -83,6 +83,7 @@
 #include "nsIServiceManager.h"
 #include "nsIDOMNode.h"
 #include "nsGUIEvent.h"
+#include "nsAutoPtr.h"
 
 static NS_DEFINE_CID(kTextNodeCID,   NS_TEXTNODE_CID);
 static NS_DEFINE_CID(kHTMLElementFactoryCID,   NS_HTML_ELEMENT_FACTORY_CID);
@@ -376,7 +377,7 @@ NS_IMETHODIMP
 nsComboboxControlFrame::Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow)
 {
    // Need to hold on the pres context because it is used later in methods
@@ -2161,23 +2162,18 @@ nsComboboxControlFrame::CreateDisplayFrame(nsIPresContext* aPresContext)
   if (!mDisplayFrame) { return NS_ERROR_NULL_POINTER; }
 
   // create the style context for the anonymous frame
-  nsCOMPtr<nsIStyleContext> styleContext;
-  rv = aPresContext->ResolvePseudoStyleContextFor(mContent, 
+  nsRefPtr<nsStyleContext> styleContext;
+  styleContext = aPresContext->ResolvePseudoStyleContextFor(mContent, 
                                                   nsCSSAnonBoxes::mozDisplayComboboxControlFrame,
-                                                  mStyleContext,
-                                                  getter_AddRefs(styleContext));
-  if (NS_FAILED(rv)) { return rv; }
+                                                  mStyleContext);
   if (!styleContext) { return NS_ERROR_NULL_POINTER; }
 
   // create a text frame and put it inside the block frame
   rv = NS_NewTextFrame(shell, &mTextFrame);
   if (NS_FAILED(rv)) { return rv; }
   if (!mTextFrame) { return NS_ERROR_NULL_POINTER; }
-  nsCOMPtr<nsIStyleContext> textStyleContext;
-  rv = aPresContext->ResolveStyleContextForNonElement(
-                                             styleContext,
-                                             getter_AddRefs(textStyleContext));
-  if (NS_FAILED(rv)) { return rv; }
+  nsRefPtr<nsStyleContext> textStyleContext;
+  textStyleContext = aPresContext->ResolveStyleContextForNonElement(styleContext);
   if (!textStyleContext) { return NS_ERROR_NULL_POINTER; }
   nsCOMPtr<nsIContent> content(do_QueryInterface(mDisplayContent));
   mTextFrame->Init(aPresContext, content, mDisplayFrame, textStyleContext, nsnull);
@@ -2301,23 +2297,18 @@ nsComboboxControlFrame::CreateFrameFor(nsIPresContext*   aPresContext,
     if (!mDisplayFrame) { return NS_ERROR_NULL_POINTER; }
 
     // create the style context for the anonymous block frame
-    nsCOMPtr<nsIStyleContext> styleContext;
-    rv = aPresContext->ResolvePseudoStyleContextFor(mContent, 
+    nsRefPtr<nsStyleContext> styleContext;
+    styleContext = aPresContext->ResolvePseudoStyleContextFor(mContent, 
                                                     nsCSSAnonBoxes::mozDisplayComboboxControlFrame,
-                                                    mStyleContext,
-                                                    getter_AddRefs(styleContext));
-    if (NS_FAILED(rv)) { return rv; }
+                                                    mStyleContext);
     if (!styleContext) { return NS_ERROR_NULL_POINTER; }
 
     // Create a text frame and put it inside the block frame
     rv = NS_NewTextFrame(shell, &mTextFrame);
     if (NS_FAILED(rv)) { return rv; }
     if (!mTextFrame)   { return NS_ERROR_NULL_POINTER; }
-    nsCOMPtr<nsIStyleContext> textStyleContext;
-    rv = aPresContext->ResolveStyleContextForNonElement(
-                                             styleContext,
-                                             getter_AddRefs(textStyleContext));
-    if (NS_FAILED(rv))     { return rv; }
+    nsRefPtr<nsStyleContext> textStyleContext;
+    textStyleContext = aPresContext->ResolveStyleContextForNonElement(styleContext);
     if (!textStyleContext) { return NS_ERROR_NULL_POINTER; }
 
     // initialize the text frame
diff --git a/mozilla/layout/forms/nsComboboxControlFrame.h b/mozilla/layout/forms/nsComboboxControlFrame.h
index 1773ffa8aee..6057ab3eb6f 100644
--- a/mozilla/layout/forms/nsComboboxControlFrame.h
+++ b/mozilla/layout/forms/nsComboboxControlFrame.h
@@ -110,7 +110,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Reflow(nsIPresContext*          aCX,
diff --git a/mozilla/layout/forms/nsFieldSetFrame.cpp b/mozilla/layout/forms/nsFieldSetFrame.cpp
index 4ae7e35ea0e..5ab147cc0ff 100644
--- a/mozilla/layout/forms/nsFieldSetFrame.cpp
+++ b/mozilla/layout/forms/nsFieldSetFrame.cpp
@@ -54,7 +54,6 @@
 #include "nsHTMLParts.h"
 #include "nsHTMLAtoms.h"
 #include "nsLayoutAtoms.h"
-#include "nsIStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsFont.h"
 #include "nsCOMPtr.h"
diff --git a/mozilla/layout/forms/nsFileControlFrame.h b/mozilla/layout/forms/nsFileControlFrame.h
index eb8f55817e1..f94f10e7c5d 100644
--- a/mozilla/layout/forms/nsFileControlFrame.h
+++ b/mozilla/layout/forms/nsFileControlFrame.h
@@ -65,7 +65,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow) {
     mPresContext = aPresContext;
     return nsAreaFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/forms/nsFormControlFrame.cpp b/mozilla/layout/forms/nsFormControlFrame.cpp
index e3de8dc461b..0438964bb6a 100644
--- a/mozilla/layout/forms/nsFormControlFrame.cpp
+++ b/mozilla/layout/forms/nsFormControlFrame.cpp
@@ -41,7 +41,6 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresShell.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
 #include "nsLeafFrame.h"
 #include "nsCSSRendering.h"
 #include "nsIView.h"
diff --git a/mozilla/layout/forms/nsFormControlFrame.h b/mozilla/layout/forms/nsFormControlFrame.h
index 665f49030d3..d82d058d0f7 100644
--- a/mozilla/layout/forms/nsFormControlFrame.h
+++ b/mozilla/layout/forms/nsFormControlFrame.h
@@ -44,7 +44,6 @@
 #include "nsIWidget.h"
 #include "nsLeafFrame.h"
 #include "nsCoord.h"
-#include "nsIStyleContext.h"
 #include "nsIPresContext.h"
 #include "nsCOMPtr.h"
 
diff --git a/mozilla/layout/forms/nsFormControlHelper.cpp b/mozilla/layout/forms/nsFormControlHelper.cpp
index a81911af453..d299b496419 100644
--- a/mozilla/layout/forms/nsFormControlHelper.cpp
+++ b/mozilla/layout/forms/nsFormControlHelper.cpp
@@ -41,7 +41,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresShell.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsLeafFrame.h"
 #include "nsCSSRendering.h"
 #include "nsIView.h"
@@ -250,7 +250,7 @@ nsFormControlHelper::GetTextSize(nsIPresContext* aPresContext, nsIFormControlFra
 nsresult  
 nsFormControlHelper::GetFont(nsIFormControlFrame * aFormFrame,
                              nsIPresContext*       aPresContext, 
-                             nsIStyleContext *     aStyleContext, 
+                             nsStyleContext *      aStyleContext, 
                              const nsFont*&        aFont)
 {
   const nsStyleFont* styleFont = (const nsStyleFont*)aStyleContext->GetStyleData(eStyleStruct_Font);
diff --git a/mozilla/layout/forms/nsFormControlHelper.h b/mozilla/layout/forms/nsFormControlHelper.h
index 9b97d801213..e7f160cd15c 100644
--- a/mozilla/layout/forms/nsFormControlHelper.h
+++ b/mozilla/layout/forms/nsFormControlHelper.h
@@ -50,7 +50,7 @@ class nsIView;
 class nsIPresContext;
 class nsStyleCoord;
 class nsIPresState;
-class nsIStyleContext;
+class nsStyleContext;
 
 #define CSS_NOTSET -1
 #define ATTR_NOTSET -1
@@ -96,7 +96,7 @@ public:
   // XXX This could be removed now that we no longer have form quirks.
   static nsresult GetFont(nsIFormControlFrame *  aFormFrame,
                           nsIPresContext*        aPresContext, 
-                          nsIStyleContext *      aStyleContext, 
+                          nsStyleContext *       aStyleContext, 
                           const nsFont*&         aFont);
 
   // returns the an addref'ed FontMetrics for the default font for the frame
@@ -330,9 +330,9 @@ public:
                             const nsRect& aDirtyRect, const nsRect& aRect, 
                             PRBool aShift, PRBool aShowFocus, PRBool aDisabled,
 							              PRBool aDrawOutline,
-							              nsIStyleContext* aOutlineStyle,
-							              nsIStyleContext* aFocusStyle,
-                            nsIStyleContext* aStyleContext, nsString& aLabel, 
+							              nsStyleContext* aOutlineStyle,
+							              nsStyleContext* aFocusStyle,
+                            nsStyleContext* aStyleContext, nsString& aLabel, 
                             nsIFrame* aForFrame);
 
   static void StyleChangeReflow(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/forms/nsGfxButtonControlFrame.cpp b/mozilla/layout/forms/nsGfxButtonControlFrame.cpp
index 865694d659d..c321e1d2127 100644
--- a/mozilla/layout/forms/nsGfxButtonControlFrame.cpp
+++ b/mozilla/layout/forms/nsGfxButtonControlFrame.cpp
@@ -50,6 +50,7 @@
 #include "nsIDOMNode.h"
 #include "nsLayoutAtoms.h"
 #include "nsReflowPath.h"
+#include "nsAutoPtr.h"
 // MouseEvent suppression in PP
 #include "nsGUIEvent.h"
 
@@ -253,17 +254,13 @@ nsGfxButtonControlFrame::CreateFrameFor(nsIPresContext*   aPresContext,
     aPresContext->GetShell(getter_AddRefs(shell));
 
     nsIFrame * parentFrame = mFrames.FirstChild();
-    nsCOMPtr<nsIStyleContext> styleContext;
-    parentFrame->GetStyleContext(getter_AddRefs(styleContext));
+    nsStyleContext* styleContext = parentFrame->GetStyleContext();
 
     rv = NS_NewTextFrame(shell, &newFrame);
     if (NS_FAILED(rv)) { return rv; }
     if (!newFrame)   { return NS_ERROR_NULL_POINTER; }
-    nsCOMPtr<nsIStyleContext> textStyleContext;
-    rv = aPresContext->ResolveStyleContextForNonElement(
-                                             styleContext,
-                                             getter_AddRefs(textStyleContext));
-    if (NS_FAILED(rv))     { return rv; }
+    nsRefPtr<nsStyleContext> textStyleContext;
+    textStyleContext = aPresContext->ResolveStyleContextForNonElement(styleContext);
     if (!textStyleContext) { return NS_ERROR_NULL_POINTER; }
 
     if (styleContext) {
diff --git a/mozilla/layout/forms/nsGfxCheckboxControlFrame.cpp b/mozilla/layout/forms/nsGfxCheckboxControlFrame.cpp
index 20d49fe67a8..1388f22b18a 100644
--- a/mozilla/layout/forms/nsGfxCheckboxControlFrame.cpp
+++ b/mozilla/layout/forms/nsGfxCheckboxControlFrame.cpp
@@ -82,7 +82,8 @@ nsGfxCheckboxControlFrame::nsGfxCheckboxControlFrame()
 
 nsGfxCheckboxControlFrame::~nsGfxCheckboxControlFrame()
 {
-  NS_IF_RELEASE(mCheckButtonFaceStyle);
+  if (mCheckButtonFaceStyle)
+    mCheckButtonFaceStyle->Release();
 }
 
 
@@ -120,53 +121,43 @@ NS_IMETHODIMP nsGfxCheckboxControlFrame::GetAccessible(nsIAccessible** aAccessib
 
 //--------------------------------------------------------------
 NS_IMETHODIMP
-nsGfxCheckboxControlFrame::SetCheckboxFaceStyleContext(nsIStyleContext *aCheckboxFaceStyleContext)
+nsGfxCheckboxControlFrame::SetCheckboxFaceStyleContext(nsStyleContext *aCheckboxFaceStyleContext)
 {
   mCheckButtonFaceStyle = aCheckboxFaceStyleContext;
-  NS_ADDREF(mCheckButtonFaceStyle);
+  mCheckButtonFaceStyle->AddRef();
   return NS_OK;
 }
 
 
 //--------------------------------------------------------------
-NS_IMETHODIMP
-nsGfxCheckboxControlFrame::GetAdditionalStyleContext(PRInt32 aIndex, 
-                                                     nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsGfxCheckboxControlFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
 {
-  NS_PRECONDITION(nsnull != aStyleContext, "null OUT parameter pointer");
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
-  *aStyleContext = nsnull;
   switch (aIndex) {
   case NS_GFX_CHECKBOX_CONTROL_FRAME_FACE_CONTEXT_INDEX:
-    *aStyleContext = mCheckButtonFaceStyle;
-    NS_IF_ADDREF(*aStyleContext);
+    return mCheckButtonFaceStyle;
     break;
   default:
-    return NS_ERROR_INVALID_ARG;
+    return nsnull;
   }
-  return NS_OK;
 }
 
 
 
 //--------------------------------------------------------------
-NS_IMETHODIMP
+void
 nsGfxCheckboxControlFrame::SetAdditionalStyleContext(PRInt32 aIndex, 
-                                                     nsIStyleContext* aStyleContext)
+                                                     nsStyleContext* aStyleContext)
 {
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
   switch (aIndex) {
   case NS_GFX_CHECKBOX_CONTROL_FRAME_FACE_CONTEXT_INDEX:
-    NS_IF_RELEASE(mCheckButtonFaceStyle);
+    if (mCheckButtonFaceStyle)
+      mCheckButtonFaceStyle->Release();
     mCheckButtonFaceStyle = aStyleContext;
-    NS_IF_ADDREF(aStyleContext);
+    if (aStyleContext)
+      aStyleContext->AddRef();
     break;
   }
-  return NS_OK;
 }
 
 
diff --git a/mozilla/layout/forms/nsGfxCheckboxControlFrame.h b/mozilla/layout/forms/nsGfxCheckboxControlFrame.h
index 80e8bd7a67e..cdca5edde99 100644
--- a/mozilla/layout/forms/nsGfxCheckboxControlFrame.h
+++ b/mozilla/layout/forms/nsGfxCheckboxControlFrame.h
@@ -77,13 +77,12 @@ public:
 
 
   //nsICheckboxControlFrame methods
-  NS_IMETHOD SetCheckboxFaceStyleContext(nsIStyleContext *aCheckboxFaceStyleContext);
+  NS_IMETHOD SetCheckboxFaceStyleContext(nsStyleContext *aCheckboxFaceStyleContext);
   NS_IMETHOD OnChecked(nsIPresContext* aPresContext, PRBool aChecked);
 
-  NS_IMETHOD GetAdditionalStyleContext(PRInt32 aIndex, 
-                                       nsIStyleContext** aStyleContext) const;
-  NS_IMETHOD SetAdditionalStyleContext(PRInt32 aIndex, 
-                                       nsIStyleContext* aStyleContext);
+  virtual nsStyleContext* GetAdditionalStyleContext(PRInt32 aIndex) const;
+  virtual void SetAdditionalStyleContext(PRInt32 aIndex,
+                                         nsStyleContext* aStyleContext);
 
     // nsIFormControlFrame
   NS_IMETHOD OnContentReset();
@@ -110,7 +109,7 @@ protected:
 
   //GFX-rendered state variables
   PRBool           mInClickEvent;
-  nsIStyleContext* mCheckButtonFaceStyle;
+  nsStyleContext*  mCheckButtonFaceStyle;
 
 private:
   NS_IMETHOD_(nsrefcnt) AddRef() { return NS_OK; }
diff --git a/mozilla/layout/forms/nsGfxRadioControlFrame.cpp b/mozilla/layout/forms/nsGfxRadioControlFrame.cpp
index bb479832eef..8bf0401f39a 100644
--- a/mozilla/layout/forms/nsGfxRadioControlFrame.cpp
+++ b/mozilla/layout/forms/nsGfxRadioControlFrame.cpp
@@ -77,7 +77,8 @@ nsGfxRadioControlFrame::nsGfxRadioControlFrame()
 
 nsGfxRadioControlFrame::~nsGfxRadioControlFrame()
 {
-  NS_IF_RELEASE(mRadioButtonFaceStyle);
+  if (mRadioButtonFaceStyle)
+    mRadioButtonFaceStyle->Release();
 }
 
 // Frames are not refcounted, no need to AddRef
@@ -110,50 +111,40 @@ NS_IMETHODIMP nsGfxRadioControlFrame::GetAccessible(nsIAccessible** aAccessible)
 #endif
 
 //--------------------------------------------------------------
-NS_IMETHODIMP
-nsGfxRadioControlFrame::GetAdditionalStyleContext(PRInt32 aIndex, 
-                                                  nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsGfxRadioControlFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
 {
-  NS_PRECONDITION(nsnull != aStyleContext, "null OUT parameter pointer");
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
-  *aStyleContext = nsnull;
   switch (aIndex) {
   case NS_GFX_RADIO_CONTROL_FRAME_FACE_CONTEXT_INDEX:
-    *aStyleContext = mRadioButtonFaceStyle;
-    NS_IF_ADDREF(*aStyleContext);
+    return mRadioButtonFaceStyle;
     break;
   default:
-    return NS_ERROR_INVALID_ARG;
+    return nsnull;
   }
-  return NS_OK;
 }
 
 //--------------------------------------------------------------
-NS_IMETHODIMP
+void
 nsGfxRadioControlFrame::SetAdditionalStyleContext(PRInt32 aIndex, 
-                                                  nsIStyleContext* aStyleContext)
+                                                  nsStyleContext* aStyleContext)
 {
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
   switch (aIndex) {
   case NS_GFX_RADIO_CONTROL_FRAME_FACE_CONTEXT_INDEX:
-    NS_IF_RELEASE(mRadioButtonFaceStyle);
+    if (mRadioButtonFaceStyle)
+      mRadioButtonFaceStyle->Release();
     mRadioButtonFaceStyle = aStyleContext;
-    NS_IF_ADDREF(aStyleContext);
+    if (aStyleContext)
+      aStyleContext->AddRef();
     break;
   }
-  return NS_OK;
 }
 
 //--------------------------------------------------------------
 NS_IMETHODIMP
-nsGfxRadioControlFrame::SetRadioButtonFaceStyleContext(nsIStyleContext *aRadioButtonFaceStyleContext)
+nsGfxRadioControlFrame::SetRadioButtonFaceStyleContext(nsStyleContext *aRadioButtonFaceStyleContext)
 {
   mRadioButtonFaceStyle = aRadioButtonFaceStyleContext;
-  NS_ADDREF(mRadioButtonFaceStyle);
+  mRadioButtonFaceStyle->AddRef();
   return NS_OK;
 }
 
diff --git a/mozilla/layout/forms/nsGfxRadioControlFrame.h b/mozilla/layout/forms/nsGfxRadioControlFrame.h
index b04f5debf6d..1d9a40b0dc8 100644
--- a/mozilla/layout/forms/nsGfxRadioControlFrame.h
+++ b/mozilla/layout/forms/nsGfxRadioControlFrame.h
@@ -62,16 +62,15 @@ public:
 
    //nsIRadioControlFrame methods
   NS_IMETHOD QueryInterface(const nsIID& aIID, void** aInstancePtr);
-  NS_IMETHOD SetRadioButtonFaceStyleContext(nsIStyleContext *aRadioButtonFaceStyleContext);
+  NS_IMETHOD SetRadioButtonFaceStyleContext(nsStyleContext *aRadioButtonFaceStyleContext);
 #ifdef ACCESSIBILITY
   NS_IMETHOD GetAccessible(nsIAccessible** aAccessible);
 #endif
   NS_IMETHOD OnChecked(nsIPresContext* aPresContext, PRBool aChecked);
 
-  NS_IMETHOD GetAdditionalStyleContext(PRInt32 aIndex, 
-                                       nsIStyleContext** aStyleContext) const;
-  NS_IMETHOD SetAdditionalStyleContext(PRInt32 aIndex, 
-                                       nsIStyleContext* aStyleContext);
+  virtual nsStyleContext* GetAdditionalStyleContext(PRInt32 aIndex) const;
+  virtual void SetAdditionalStyleContext(PRInt32 aIndex,
+                                         nsStyleContext* aStyleContext);
 
   NS_IMETHOD HandleEvent(nsIPresContext* aPresContext, 
                          nsGUIEvent* aEvent,
@@ -106,7 +105,7 @@ public:
 protected:
 
     //GFX-rendered state variables
-  nsIStyleContext* mRadioButtonFaceStyle;
+  nsStyleContext* mRadioButtonFaceStyle;
 
 private:
   NS_IMETHOD_(nsrefcnt) AddRef() { return NS_OK; }
diff --git a/mozilla/layout/forms/nsHTMLButtonControlFrame.cpp b/mozilla/layout/forms/nsHTMLButtonControlFrame.cpp
index d90f1f9a49f..ad4771d04d9 100644
--- a/mozilla/layout/forms/nsHTMLButtonControlFrame.cpp
+++ b/mozilla/layout/forms/nsHTMLButtonControlFrame.cpp
@@ -47,7 +47,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresContext.h"
 #include "nsIPresShell.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsLeafFrame.h"
 #include "nsCSSRendering.h"
 #include "nsISupports.h"
@@ -123,7 +123,7 @@ NS_IMETHODIMP
 nsHTMLButtonControlFrame::Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow)
 {
   nsresult  rv = nsHTMLContainerFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
@@ -145,13 +145,11 @@ nsHTMLButtonControlFrame::Init(nsIPresContext*  aPresContext,
   mFrames.SetFrames(areaFrame);
 
   // Resolve style and initialize the frame
-  nsIStyleContext* styleContext;
-  aPresContext->ResolvePseudoStyleContextFor(mContent,
+  nsRefPtr<nsStyleContext> styleContext;
+  styleContext = aPresContext->ResolvePseudoStyleContextFor(mContent,
                                             nsCSSAnonBoxes::buttonContent,
-                                            mStyleContext,
-                                            &styleContext);
+                                            mStyleContext);
   mFrames.FirstChild()->Init(aPresContext, mContent, this, styleContext, nsnull);
-  NS_RELEASE(styleContext);                                           
 
   return rv;
 }
@@ -333,14 +331,14 @@ nsHTMLButtonControlFrame::SetInitialChildList(nsIPresContext* aPresContext,
   //
   nsCOMPtr<nsIPresShell> shell;
   nsCOMPtr<nsIFrameManager> frameManager;
-  nsCOMPtr<nsIStyleContext> newParentContext;
+  nsStyleContext* newParentContext;
   aPresContext->GetShell(getter_AddRefs(shell));
   if (shell) {
     shell->GetFrameManager(getter_AddRefs(frameManager));
   }
   // get the new parent context from the first child: that is the frame that the
   // subsequent children will be made children of
-  mFrames.FirstChild()->GetStyleContext(getter_AddRefs(newParentContext));
+  newParentContext = mFrames.FirstChild()->GetStyleContext();
 
   // Set the parent for each of the child frames
   for (nsIFrame* frame = aChildList; nsnull != frame; frame->GetNextSibling(&frame)) {
@@ -691,18 +689,17 @@ NS_IMETHODIMP nsHTMLButtonControlFrame::GetProperty(nsIAtom* aName, nsAString& a
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsHTMLButtonControlFrame::GetAdditionalStyleContext(PRInt32 aIndex, 
-                                                    nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsHTMLButtonControlFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
 {
-  return mRenderer.GetStyleContext(aIndex, aStyleContext);
+  return mRenderer.GetStyleContext(aIndex);
 }
 
-NS_IMETHODIMP
+void
 nsHTMLButtonControlFrame::SetAdditionalStyleContext(PRInt32 aIndex, 
-                                                    nsIStyleContext* aStyleContext)
+                                                    nsStyleContext* aStyleContext)
 {
-  return mRenderer.SetStyleContext(aIndex, aStyleContext);
+  mRenderer.SetStyleContext(aIndex, aStyleContext);
 }
 
 
diff --git a/mozilla/layout/forms/nsHTMLButtonControlFrame.h b/mozilla/layout/forms/nsHTMLButtonControlFrame.h
index 95a5f7c3c8a..037bee97364 100644
--- a/mozilla/layout/forms/nsHTMLButtonControlFrame.h
+++ b/mozilla/layout/forms/nsHTMLButtonControlFrame.h
@@ -48,7 +48,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresContext.h"
 #include "nsIPresShell.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsLeafFrame.h"
 #include "nsCSSRendering.h"
 #include "nsISupports.h"
@@ -102,13 +102,12 @@ public:
   NS_IMETHOD  Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        asPrevInFlow);
 
-  NS_IMETHOD  GetAdditionalStyleContext(PRInt32 aIndex, 
-                                        nsIStyleContext** aStyleContext) const;
-  NS_IMETHOD  SetAdditionalStyleContext(PRInt32 aIndex, 
-                                        nsIStyleContext* aStyleContext);
+  virtual nsStyleContext* GetAdditionalStyleContext(PRInt32 aIndex) const;
+  virtual void SetAdditionalStyleContext(PRInt32 aIndex, 
+                                         nsStyleContext* aStyleContext);
  
   NS_IMETHOD  AppendFrames(nsIPresContext* aPresContext,
                            nsIPresShell&   aPresShell,
diff --git a/mozilla/layout/forms/nsICheckboxControlFrame.h b/mozilla/layout/forms/nsICheckboxControlFrame.h
index e74b399816d..f22525fdeab 100644
--- a/mozilla/layout/forms/nsICheckboxControlFrame.h
+++ b/mozilla/layout/forms/nsICheckboxControlFrame.h
@@ -39,7 +39,7 @@
 #define nsICheckControlFrame_h___
 
 #include "nsISupports.h"
-class nsIStyleContext;
+class nsStyleContext;
 class nsIPresContext;
 
 // IID for the nsICheckControlFrame class
@@ -61,7 +61,7 @@ public:
    * Sets the Pseudo Style Contexts for the Check button
    */
   NS_IMETHOD SetCheckboxFaceStyleContext(
-                 nsIStyleContext* aCheckboxFaceStyleContext) = 0;
+                 nsStyleContext* aCheckboxFaceStyleContext) = 0;
   
   /**
    * Called by content when checkbox "checked" changes
diff --git a/mozilla/layout/forms/nsIRadioControlFrame.h b/mozilla/layout/forms/nsIRadioControlFrame.h
index 3da9d8674e1..d5f944bf287 100644
--- a/mozilla/layout/forms/nsIRadioControlFrame.h
+++ b/mozilla/layout/forms/nsIRadioControlFrame.h
@@ -39,7 +39,7 @@
 #define nsIRadioControlFrame_h___
 
 #include "nsISupports.h"
-class nsIStyleContext;
+class nsStyleContext;
 
 // IID for the nsIRadioControlFrame class
 // {06450E00-24D9-11d3-966B-00105A1B1B76}
@@ -61,7 +61,7 @@ public:
    * Sets the Pseudo Style Contexts for the Radio button
    */
 
-   NS_IMETHOD SetRadioButtonFaceStyleContext(nsIStyleContext *aRadioButtonFaceStyleContext) = 0;
+   NS_IMETHOD SetRadioButtonFaceStyleContext(nsStyleContext *aRadioButtonFaceStyleContext) = 0;
 
    /**
     * Called by content when the radio button's state changes
diff --git a/mozilla/layout/forms/nsImageControlFrame.cpp b/mozilla/layout/forms/nsImageControlFrame.cpp
index e9aa0d5e4a2..c8208591e4c 100644
--- a/mozilla/layout/forms/nsImageControlFrame.cpp
+++ b/mozilla/layout/forms/nsImageControlFrame.cpp
@@ -44,7 +44,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresContext.h"
 #include "nsIPresShell.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsLeafFrame.h"
 #include "nsCSSRendering.h"
 #include "nsIViewManager.h"
@@ -91,7 +91,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Reflow(nsIPresContext*          aPresContext,
@@ -260,7 +260,7 @@ NS_IMETHODIMP
 nsImageControlFrame::Init(nsIPresContext*  aPresContext,
                           nsIContent*      aContent,
                           nsIFrame*        aParent,
-                          nsIStyleContext* aContext,
+                          nsStyleContext*  aContext,
                           nsIFrame*        aPrevInFlow)
 {
   // call our base class
diff --git a/mozilla/layout/forms/nsIsIndexFrame.h b/mozilla/layout/forms/nsIsIndexFrame.h
index 4f615654b51..e595ef3123b 100644
--- a/mozilla/layout/forms/nsIsIndexFrame.h
+++ b/mozilla/layout/forms/nsIsIndexFrame.h
@@ -72,7 +72,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow) {
     mPresContext = aPresContext;
     return nsAreaFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/forms/nsListControlFrame.cpp b/mozilla/layout/forms/nsListControlFrame.cpp
index 99363b0f6f1..2ef29851dab 100644
--- a/mozilla/layout/forms/nsListControlFrame.cpp
+++ b/mozilla/layout/forms/nsListControlFrame.cpp
@@ -1091,8 +1091,7 @@ nsListControlFrame::Reflow(nsIPresContext*          aPresContext,
       mPresContext->GetShell(getter_AddRefs(presShell));
       nsresult result = presShell->GetPrimaryFrameFor(option, &optFrame);
       if (NS_SUCCEEDED(result) && optFrame != nsnull) {
-        nsCOMPtr<nsIStyleContext> optStyle;
-        optFrame->GetStyleContext(getter_AddRefs(optStyle));
+        nsStyleContext* optStyle = optFrame->GetStyleContext();
         if (optStyle) {
           const nsStyleFont* styleFont = (const nsStyleFont*)optStyle->GetStyleData(eStyleStruct_Font);
           nsCOMPtr<nsIDeviceContext> deviceContext;
@@ -1751,7 +1750,7 @@ NS_IMETHODIMP
 nsListControlFrame::Init(nsIPresContext*  aPresContext,
                          nsIContent*      aContent,
                          nsIFrame*        aParent,
-                         nsIStyleContext* aContext,
+                         nsStyleContext*  aContext,
                          nsIFrame*        aPrevInFlow)
 {
   mPresContext = aPresContext;
diff --git a/mozilla/layout/forms/nsListControlFrame.h b/mozilla/layout/forms/nsListControlFrame.h
index f71b21e7ef0..897302b5db3 100644
--- a/mozilla/layout/forms/nsListControlFrame.h
+++ b/mozilla/layout/forms/nsListControlFrame.h
@@ -201,7 +201,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD DidReflow(nsIPresContext*           aPresContext, 
diff --git a/mozilla/layout/generic/nsAreaFrame.cpp b/mozilla/layout/generic/nsAreaFrame.cpp
index bab53c25640..27fd2843e28 100644
--- a/mozilla/layout/generic/nsAreaFrame.cpp
+++ b/mozilla/layout/generic/nsAreaFrame.cpp
@@ -36,7 +36,7 @@
  * ***** END LICENSE BLOCK ***** */
 #include "nsAreaFrame.h"
 #include "nsBlockBandData.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIPresContext.h"
 #include "nsIViewManager.h"
@@ -143,7 +143,7 @@ NS_IMETHODIMP
 nsAreaFrame::Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsBlockFrame::Init(aPresContext,
diff --git a/mozilla/layout/generic/nsAreaFrame.h b/mozilla/layout/generic/nsAreaFrame.h
index 96a4abc9bc0..add72c3cd9a 100644
--- a/mozilla/layout/generic/nsAreaFrame.h
+++ b/mozilla/layout/generic/nsAreaFrame.h
@@ -62,7 +62,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
diff --git a/mozilla/layout/generic/nsBlockFrame.cpp b/mozilla/layout/generic/nsBlockFrame.cpp
index 370d72c812e..508cd9989c8 100644
--- a/mozilla/layout/generic/nsBlockFrame.cpp
+++ b/mozilla/layout/generic/nsBlockFrame.cpp
@@ -53,7 +53,7 @@
 #include "nsIPresContext.h"
 #include "nsIPresShell.h"
 #include "nsReflowPath.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIView.h"
 #include "nsIFontMetrics.h"
 #include "nsHTMLParts.h"
@@ -75,6 +75,7 @@
 #include "plstr.h"
 #include "nsGUIEvent.h"
 #include "nsLayoutErrors.h"
+#include "nsAutoPtr.h"
 
 #ifdef IBMBIDI
 #include "nsBidiPresUtils.h"
@@ -198,13 +199,11 @@ DumpStyleGeneaology(nsIFrame* aFrame, const char* gap)
   fputs(gap, stdout);
   nsFrame::ListTag(stdout, aFrame);
   printf(": ");
-  nsIStyleContext* sc;
-  aFrame->GetStyleContext(&sc);
+  nsStyleContext* sc = aFrame->GetStyleContext();
   while (nsnull != sc) {
-    nsIStyleContext* psc;
+    nsStyleContext* psc;
     printf("%p ", sc);
     psc = sc->GetParent();
-    NS_RELEASE(sc);
     sc = psc;
   }
   printf("\n");
@@ -5554,7 +5553,7 @@ nsBlockFrame::IsVisibleForPainting(nsIPresContext *     aPresContext,
   // first check to see if we are visible
   if (aCheckVis) {
     const nsStyleVisibility* vis = 
-      (const nsStyleVisibility*)((nsIStyleContext*)mStyleContext)->GetStyleData(eStyleStruct_Visibility);
+      (const nsStyleVisibility*)mStyleContext->GetStyleData(eStyleStruct_Visibility);
     if (!vis->IsVisible()) {
       *aIsVisible = PR_FALSE;
       return NS_OK;
@@ -6308,7 +6307,7 @@ NS_IMETHODIMP
 nsBlockFrame::Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        aPrevInFlow)
 {
   if (aPrevInFlow) {
@@ -6323,7 +6322,7 @@ nsBlockFrame::Init(nsIPresContext*  aPresContext,
   return rv;
 }
 
-nsIStyleContext*
+already_AddRefed<nsStyleContext>
 nsBlockFrame::GetFirstLetterStyle(nsIPresContext* aPresContext)
 {
   // This check is here because nsComboboxControlFrame creates
@@ -6336,11 +6335,9 @@ nsBlockFrame::GetFirstLetterStyle(nsIPresContext* aPresContext)
   if (!mContent->IsContentOfType(nsIContent::eELEMENT))
     return nsnull;
 
-  nsIStyleContext* fls;
-  aPresContext->ProbePseudoStyleContextFor(mContent,
-                                           nsCSSPseudoElements::firstLetter,
-                                           mStyleContext, &fls);
-  return fls;
+  return aPresContext->ProbePseudoStyleContextFor(mContent,
+                                                  nsCSSPseudoElements::firstLetter,
+                                                  mStyleContext);
 }
 
 NS_IMETHODIMP
@@ -6360,14 +6357,13 @@ nsBlockFrame::SetInitialChildList(nsIPresContext* aPresContext,
 
     // Lookup up the two pseudo style contexts
     if (nsnull == mPrevInFlow) {
-      nsIStyleContext* firstLetterStyle = GetFirstLetterStyle(aPresContext);
+      nsRefPtr<nsStyleContext> firstLetterStyle = GetFirstLetterStyle(aPresContext);
       if (nsnull != firstLetterStyle) {
         mState |= NS_BLOCK_HAS_FIRST_LETTER_STYLE;
 #ifdef NOISY_FIRST_LETTER
         ListTag(stdout);
         printf(": first-letter style found\n");
 #endif
-        NS_RELEASE(firstLetterStyle);
       }
     }
 
@@ -6398,9 +6394,7 @@ nsBlockFrame::SetInitialChildList(nsIPresContext* aPresContext,
           pseudoElement = nsCSSPseudoElements::mozListNumber;
           break;
       }
-      nsIStyleContext* kidSC;
-      aPresContext->ResolvePseudoStyleContextFor(mContent, pseudoElement,
-                                                 mStyleContext, &kidSC);
+      nsRefPtr<nsStyleContext> kidSC = aPresContext->ResolvePseudoStyleContextFor(mContent, pseudoElement, mStyleContext);
 
       // Create bullet frame
       nsCOMPtr<nsIPresShell> shell;
@@ -6408,11 +6402,9 @@ nsBlockFrame::SetInitialChildList(nsIPresContext* aPresContext,
       mBullet = new (shell.get()) nsBulletFrame;
 
       if (nsnull == mBullet) {
-        NS_RELEASE(kidSC);
         return NS_ERROR_OUT_OF_MEMORY;
       }
       mBullet->Init(aPresContext, mContent, this, kidSC, nsnull);
-      NS_RELEASE(kidSC);
 
       // If the list bullet frame should be positioned inside then add
       // it to the flow now.
diff --git a/mozilla/layout/generic/nsBlockFrame.h b/mozilla/layout/generic/nsBlockFrame.h
index 8ec8a718201..623cff9ad41 100644
--- a/mozilla/layout/generic/nsBlockFrame.h
+++ b/mozilla/layout/generic/nsBlockFrame.h
@@ -99,7 +99,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   NS_IMETHOD SetInitialChildList(nsIPresContext* aPresContext,
                                  nsIAtom*        aListName,
@@ -210,7 +210,7 @@ protected:
   nsBlockFrame();
   virtual ~nsBlockFrame();
 
-  nsIStyleContext* GetFirstLetterStyle(nsIPresContext* aPresContext);
+  already_AddRefed<nsStyleContext> GetFirstLetterStyle(nsIPresContext* aPresContext);
 
   /*
    * Overides member function of nsHTMLContainerFrame. Needed to handle the 
diff --git a/mozilla/layout/generic/nsBlockReflowContext.cpp b/mozilla/layout/generic/nsBlockReflowContext.cpp
index e35bfb713da..a1b6318e83a 100644
--- a/mozilla/layout/generic/nsBlockReflowContext.cpp
+++ b/mozilla/layout/generic/nsBlockReflowContext.cpp
@@ -42,7 +42,7 @@
 #include "nsIFontMetrics.h"
 #include "nsIPresContext.h"
 #include "nsIContent.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsHTMLReflowCommand.h"
 #include "nsHTMLContainerFrame.h"
 #include "nsBlockFrame.h"
@@ -786,8 +786,7 @@ nsStyleUnit
 nsBlockReflowContext::GetRealMarginLeftUnit()
 {
   nsStyleUnit unit = eStyleUnit_Inherit;
-  nsCOMPtr<nsIStyleContext> sc;
-  mFrame->GetStyleContext(getter_AddRefs(sc));
+  nsStyleContext* sc = mFrame->GetStyleContext();
   while (sc && eStyleUnit_Inherit == unit) {
     // Get parent style context
     sc = sc->GetParent();
@@ -807,8 +806,7 @@ nsStyleUnit
 nsBlockReflowContext::GetRealMarginRightUnit()
 {
   nsStyleUnit unit = eStyleUnit_Inherit;
-  nsCOMPtr<nsIStyleContext> sc;
-  mFrame->GetStyleContext(getter_AddRefs(sc));
+  nsStyleContext* sc = mFrame->GetStyleContext();
   while (sc && eStyleUnit_Inherit == unit) {
     // Get parent style context
     sc = sc->GetParent();
diff --git a/mozilla/layout/generic/nsBulletFrame.cpp b/mozilla/layout/generic/nsBulletFrame.cpp
index 2212c45faa6..eed04aea899 100644
--- a/mozilla/layout/generic/nsBulletFrame.cpp
+++ b/mozilla/layout/generic/nsBulletFrame.cpp
@@ -113,7 +113,7 @@ NS_IMETHODIMP
 nsBulletFrame::Init(nsIPresContext*  aPresContext,
                     nsIContent*      aContent,
                     nsIFrame*        aParent,
-                    nsIStyleContext* aContext,
+                    nsStyleContext*  aContext,
                     nsIFrame*        aPrevInFlow)
 {
   nsresult  rv = nsFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/generic/nsBulletFrame.h b/mozilla/layout/generic/nsBulletFrame.h
index db8e0631bc1..25cb6643fe5 100644
--- a/mozilla/layout/generic/nsBulletFrame.h
+++ b/mozilla/layout/generic/nsBulletFrame.h
@@ -38,7 +38,7 @@
 #define nsBulletFrame_h___
 
 #include "nsFrame.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 
 #include "imgIRequest.h"
 #include "imgIDecoderObserver.h"
@@ -57,7 +57,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
   NS_IMETHOD Paint(nsIPresContext*      aCX,
diff --git a/mozilla/layout/generic/nsContainerFrame.cpp b/mozilla/layout/generic/nsContainerFrame.cpp
index 779914bd1fd..d7a65cea61c 100644
--- a/mozilla/layout/generic/nsContainerFrame.cpp
+++ b/mozilla/layout/generic/nsContainerFrame.cpp
@@ -39,7 +39,7 @@
 #include "nsIContent.h"
 #include "nsIPresContext.h"
 #include "nsIRenderingContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsRect.h"
 #include "nsPoint.h"
 #include "nsGUIEvent.h"
@@ -84,7 +84,7 @@ NS_IMETHODIMP
 nsContainerFrame::Init(nsIPresContext*  aPresContext,
                        nsIContent*      aContent,
                        nsIFrame*        aParent,
-                       nsIStyleContext* aContext,
+                       nsStyleContext*  aContext,
                        nsIFrame*        aPrevInFlow)
 {
   nsresult rv;
@@ -514,7 +514,7 @@ NonZeroStyleCoord(const nsStyleCoord& aCoord) {
 }
 
 static PRBool
-HasNonZeroBorderRadius(nsIStyleContext* aStyleContext) {
+HasNonZeroBorderRadius(nsStyleContext* aStyleContext) {
   const nsStyleBorder* border;
   ::GetStyleData(aStyleContext, &border);
 
@@ -534,7 +534,7 @@ HasNonZeroBorderRadius(nsIStyleContext* aStyleContext) {
 static void
 SyncFrameViewGeometryDependentProperties(nsIPresContext*  aPresContext,
                                          nsIFrame*        aFrame,
-                                         nsIStyleContext* aStyleContext,
+                                         nsStyleContext*  aStyleContext,
                                          nsIView*         aView,
                                          PRUint32         aFlags)
 {
@@ -735,8 +735,7 @@ nsContainerFrame::SyncFrameViewAfterReflow(nsIPresContext* aPresContext,
     // detect whether it has or not. Likewise, whether the view size
     // has changed or not, we may need to change the transparency
     // state even if there is no clip.
-    nsCOMPtr<nsIStyleContext> savedStyleContext;
-    aFrame->GetStyleContext(getter_AddRefs(savedStyleContext));
+    nsStyleContext* savedStyleContext = aFrame->GetStyleContext();
     SyncFrameViewGeometryDependentProperties(aPresContext, aFrame, savedStyleContext, aView, aFlags);
   }
 }
@@ -744,7 +743,7 @@ nsContainerFrame::SyncFrameViewAfterReflow(nsIPresContext* aPresContext,
 void
 nsContainerFrame::SyncFrameViewAfterSizeChange(nsIPresContext*  aPresContext,
                                                nsIFrame*        aFrame,
-                                               nsIStyleContext* aStyleContext,
+                                               nsStyleContext*  aStyleContext,
                                                nsIView*         aView,
                                                PRUint32         aFlags)
 {
@@ -752,10 +751,8 @@ nsContainerFrame::SyncFrameViewAfterSizeChange(nsIPresContext*  aPresContext,
     return;
   }
   
-  nsCOMPtr<nsIStyleContext> savedStyleContext;
   if (nsnull == aStyleContext) {
-    aFrame->GetStyleContext(getter_AddRefs(savedStyleContext));
-    aStyleContext = savedStyleContext;
+    aStyleContext = aFrame->GetStyleContext();
   }
 
   SyncFrameViewGeometryDependentProperties(aPresContext, aFrame, aStyleContext, aView, aFlags);
@@ -764,7 +761,7 @@ nsContainerFrame::SyncFrameViewAfterSizeChange(nsIPresContext*  aPresContext,
 void
 nsContainerFrame::SyncFrameViewProperties(nsIPresContext*  aPresContext,
                                           nsIFrame*        aFrame,
-                                          nsIStyleContext* aStyleContext,
+                                          nsStyleContext*  aStyleContext,
                                           nsIView*         aView,
                                           PRUint32         aFlags)
 {
@@ -775,10 +772,8 @@ nsContainerFrame::SyncFrameViewProperties(nsIPresContext*  aPresContext,
   nsCOMPtr<nsIViewManager> vm;
   aView->GetViewManager(*getter_AddRefs(vm));
 
-  nsCOMPtr<nsIStyleContext> savedStyleContext;
   if (nsnull == aStyleContext) {
-    aFrame->GetStyleContext(getter_AddRefs(savedStyleContext));
-    aStyleContext = savedStyleContext;
+    aStyleContext = aFrame->GetStyleContext();
   }
     
   const nsStyleVisibility* vis;
@@ -859,7 +854,7 @@ nsContainerFrame::SyncFrameViewProperties(nsIPresContext*  aPresContext,
 PRBool
 nsContainerFrame::FrameNeedsView(nsIPresContext* aPresContext,
                                  nsIFrame* aFrame,
-                                 nsIStyleContext* aStyleContext)
+                                 nsStyleContext* aStyleContext)
 {
   const nsStyleVisibility* vis;
   ::GetStyleData(aStyleContext, &vis);
@@ -887,8 +882,7 @@ nsContainerFrame::FrameNeedsView(nsIPresContext* aPresContext,
     return PR_TRUE;
   } 
 
-  nsCOMPtr<nsIAtom>  pseudoTag;
-  aStyleContext->GetPseudoType(*getter_AddRefs(pseudoTag));
+  nsCOMPtr<nsIAtom>  pseudoTag = aStyleContext->GetPseudoType();
   if (pseudoTag == nsCSSAnonBoxes::scrolledContent) {
     return PR_TRUE;
   }
diff --git a/mozilla/layout/generic/nsContainerFrame.h b/mozilla/layout/generic/nsContainerFrame.h
index 444d9efcd2d..8b859a1701b 100644
--- a/mozilla/layout/generic/nsContainerFrame.h
+++ b/mozilla/layout/generic/nsContainerFrame.h
@@ -57,7 +57,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   NS_IMETHOD SetInitialChildList(nsIPresContext* aPresContext,
                                  nsIAtom*        aListName,
@@ -118,7 +118,7 @@ public:
   // @param aStyleContext can be null, in which case the frame's style context is used
   static void SyncFrameViewAfterSizeChange(nsIPresContext*  aPresContext,
                                            nsIFrame*        aFrame,
-                                           nsIStyleContext* aStyleContext,
+                                           nsStyleContext*  aStyleContext,
                                            nsIView*         aView,
                                            PRUint32         aFlags = 0);
   
@@ -132,13 +132,13 @@ public:
   // @param aStyleContext can be null, in which case the frame's style context is used
   static void SyncFrameViewProperties(nsIPresContext*  aPresContext,
                                       nsIFrame*        aFrame,
-                                      nsIStyleContext* aStyleContext,
+                                      nsStyleContext*  aStyleContext,
                                       nsIView*         aView,
                                       PRUint32         aFlags = 0);
 
   // Returns PR_TRUE if the frame requires a view
   static PRBool FrameNeedsView(nsIPresContext* aPresContext,
-                               nsIFrame* aFrame, nsIStyleContext* aStyleContext);
+                               nsIFrame* aFrame, nsStyleContext* aStyleContext);
   
   /**
    * Invokes the WillReflow() function, positions the frame and its view (if
diff --git a/mozilla/layout/generic/nsFirstLetterFrame.cpp b/mozilla/layout/generic/nsFirstLetterFrame.cpp
index 970f1acda2a..b8b5ef0f4ae 100644
--- a/mozilla/layout/generic/nsFirstLetterFrame.cpp
+++ b/mozilla/layout/generic/nsFirstLetterFrame.cpp
@@ -37,11 +37,12 @@
 #include "nsCOMPtr.h"
 #include "nsHTMLContainerFrame.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIContent.h"
 #include "nsLineLayout.h"
 #include "nsHTMLAtoms.h"
 #include "nsLayoutAtoms.h"
+#include "nsAutoPtr.h"
 
 #define nsFirstLetterFrameSuper nsHTMLContainerFrame
 
@@ -52,7 +53,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   NS_IMETHOD SetInitialChildList(nsIPresContext* aPresContext,
                                  nsIAtom*        aListName,
@@ -128,23 +129,18 @@ NS_IMETHODIMP
 nsFirstLetterFrame::Init(nsIPresContext*  aPresContext,
                          nsIContent*      aContent,
                          nsIFrame*        aParent,
-                         nsIStyleContext* aContext,
+                         nsStyleContext*  aContext,
                          nsIFrame*        aPrevInFlow)
 {
   nsresult rv;
-  nsCOMPtr<nsIStyleContext> newSC;
+  nsRefPtr<nsStyleContext> newSC;
   if (aPrevInFlow) {
     // Get proper style context for ourselves.  We're creating the frame
     // that represents everything *except* the first letter, so just create
     // a style context like we would for a text node.
-    nsCOMPtr<nsIStyleContext> parentStyleContext = aContext->GetParent();
+    nsStyleContext* parentStyleContext = aContext->GetParent();
     if (parentStyleContext) {
-      rv = aPresContext->ResolveStyleContextForNonElement(
-                                                   parentStyleContext,
-                                                   getter_AddRefs(newSC));
-      if (NS_FAILED(rv))
-        return rv;
-
+      newSC = aPresContext->ResolveStyleContextForNonElement(parentStyleContext);
       if (newSC)
         aContext = newSC;
     }
@@ -350,14 +346,13 @@ nsFirstLetterFrame::DrainOverflowFrames(nsIPresContext* aPresContext)
   // are reflowed)
   nsIFrame* kid = mFrames.FirstChild();
   if (kid) {
-    nsCOMPtr<nsIStyleContext> sc;
+    nsRefPtr<nsStyleContext> sc;
     nsCOMPtr<nsIContent> kidContent;
     kid->GetContent(getter_AddRefs(kidContent));
     if (kidContent) {
       NS_ASSERTION(kidContent->IsContentOfType(nsIContent::eTEXT),
                    "should contain only text nodes");
-      aPresContext->ResolveStyleContextForNonElement(mStyleContext,
-                                                     getter_AddRefs(sc));
+      sc = aPresContext->ResolveStyleContextForNonElement(mStyleContext);
       if (sc) {
         kid->SetStyleContext(aPresContext, sc);
       }
diff --git a/mozilla/layout/generic/nsFrame.cpp b/mozilla/layout/generic/nsFrame.cpp
index 65cc21badaf..5fe6b2a23cd 100644
--- a/mozilla/layout/generic/nsFrame.cpp
+++ b/mozilla/layout/generic/nsFrame.cpp
@@ -44,7 +44,7 @@
 #include "nsIAtom.h"
 #include "nsIArena.h"
 #include "nsString.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIView.h"
 #include "nsIViewManager.h"
 #include "nsIPresContext.h"
@@ -397,7 +397,7 @@ nsresult NS_NewSelectionImageService(nsISelectionImageService** aResult)
 //end selection service
 
 // a handy utility to set font
-void SetFontFromStyle(nsIRenderingContext* aRC, nsIStyleContext* aSC) 
+void SetFontFromStyle(nsIRenderingContext* aRC, nsStyleContext* aSC) 
 {
   const nsStyleFont *font = (const nsStyleFont*)
     aSC->GetStyleData(eStyleStruct_Font);
@@ -479,7 +479,8 @@ nsFrame::~nsFrame()
   MOZ_COUNT_DTOR(nsFrame);
 
   NS_IF_RELEASE(mContent);
-  NS_IF_RELEASE(mStyleContext);
+  if (mStyleContext)
+    mStyleContext->Release();
 }
 
 /////////////////////////////////////////////////////////////////////////////
@@ -525,7 +526,7 @@ NS_IMETHODIMP
 nsFrame::Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow)
 {
   mContent = aContent;
@@ -554,7 +555,8 @@ nsFrame::Init(nsIPresContext*  aPresContext,
     mState |= state & (NS_FRAME_INDEPENDENT_SELECTION |
                        NS_FRAME_GENERATED_CONTENT);
   }
-  return SetStyleContext(aPresContext, aContext);
+  SetStyleContext(aPresContext, aContext);
+  return NS_OK;
 }
 
 NS_IMETHODIMP nsFrame::SetInitialChildList(nsIPresContext* aPresContext,
@@ -688,25 +690,18 @@ NS_IMETHODIMP  nsFrame::CalcBorderPadding(nsMargin& aBorderPadding) const {
   return NS_ERROR_FAILURE;
 }
 
-NS_IMETHODIMP
-nsFrame::GetAdditionalStyleContext(PRInt32 aIndex, 
-                                   nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
 {
   NS_PRECONDITION(aIndex >= 0, "invalid index number");
-  NS_ASSERTION(aStyleContext, "null ptr");
-  if (! aStyleContext) {
-    return NS_ERROR_NULL_POINTER;
-  }
-  *aStyleContext = nsnull;
-  return NS_ERROR_INVALID_ARG;
+  return nsnull;
 }
 
-NS_IMETHODIMP
+void
 nsFrame::SetAdditionalStyleContext(PRInt32 aIndex, 
-                                   nsIStyleContext* aStyleContext)
+                                   nsStyleContext* aStyleContext)
 {
   NS_PRECONDITION(aIndex >= 0, "invalid index number");
-  return ((aIndex < 0) ? NS_ERROR_INVALID_ARG : NS_OK);
 }
 
 // Child frame enumeration
@@ -2103,7 +2098,7 @@ nsFrame::GetFrameForPoint(nsIPresContext* aPresContext,
   if ((aWhichLayer == NS_FRAME_PAINT_LAYER_FOREGROUND) &&
       (mRect.Contains(aPoint))) {
     const nsStyleVisibility* vis = 
-      (const nsStyleVisibility*)((nsIStyleContext*)mStyleContext)->GetStyleData(eStyleStruct_Visibility);
+      (const nsStyleVisibility*)((nsStyleContext*)mStyleContext)->GetStyleData(eStyleStruct_Visibility);
     if (vis->IsVisible()) {
       *aFrame = this;
       return NS_OK;
@@ -2898,7 +2893,7 @@ nsFrame::IsVisibleForPainting(nsIPresContext *     aPresContext,
   // first check to see if we are visible
   if (aCheckVis) {
     const nsStyleVisibility* vis = 
-      (const nsStyleVisibility*)((nsIStyleContext*)mStyleContext)->GetStyleData(eStyleStruct_Visibility);
+      (const nsStyleVisibility*)((nsStyleContext*)mStyleContext)->GetStyleData(eStyleStruct_Visibility);
     if (!vis->IsVisible()) {
       *aIsVisible = PR_FALSE;
       return NS_OK;
diff --git a/mozilla/layout/generic/nsFrame.h b/mozilla/layout/generic/nsFrame.h
index 69579b87143..6973021546b 100644
--- a/mozilla/layout/generic/nsFrame.h
+++ b/mozilla/layout/generic/nsFrame.h
@@ -112,7 +112,7 @@
 #endif
 
 // handy utilities
-extern void SetFontFromStyle(nsIRenderingContext* aRC, nsIStyleContext* aSC);
+extern void SetFontFromStyle(nsIRenderingContext* aRC, nsStyleContext* aSC);
 
 //----------------------------------------------------------------------
 
@@ -158,7 +158,7 @@ public:
   NS_IMETHOD  Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        asPrevInFlow);
   NS_IMETHOD  SetInitialChildList(nsIPresContext* aPresContext,
                                   nsIAtom*        aListName,
@@ -183,10 +183,9 @@ public:
                            nsIFrame*       aNewFrame);
   NS_IMETHOD  Destroy(nsIPresContext* aPresContext);
   NS_IMETHOD  CalcBorderPadding(nsMargin& aBorderPadding) const;
-  NS_IMETHOD  GetAdditionalStyleContext(PRInt32 aIndex, 
-                                        nsIStyleContext** aStyleContext) const;
-  NS_IMETHOD  SetAdditionalStyleContext(PRInt32 aIndex, 
-                                        nsIStyleContext* aStyleContext);
+  virtual nsStyleContext* GetAdditionalStyleContext(PRInt32 aIndex) const;
+  virtual void SetAdditionalStyleContext(PRInt32 aIndex,
+                                         nsStyleContext* aStyleContext);
   NS_IMETHOD  GetAdditionalChildListName(PRInt32 aIndex, nsIAtom** aListName) const;
   NS_IMETHOD  FirstChild(nsIPresContext* aPresContext,
                          nsIAtom*        aListName,
diff --git a/mozilla/layout/generic/nsFrameFrame.cpp b/mozilla/layout/generic/nsFrameFrame.cpp
index 4e0fbb94764..29b227f1d21 100644
--- a/mozilla/layout/generic/nsFrameFrame.cpp
+++ b/mozilla/layout/generic/nsFrameFrame.cpp
@@ -65,7 +65,7 @@
 #include "nsHTMLAtoms.h"
 #include "nsIScrollableView.h"
 #include "nsStyleCoord.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIDocumentLoader.h"
 #include "nsFrameSetFrame.h"
@@ -94,6 +94,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIFrameFrame.h"
 #include "nsIPluginViewer.h"
+#include "nsAutoPtr.h"
 
 // For Accessibility
 #ifdef ACCESSIBILITY
@@ -156,7 +157,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Reflow(nsIPresContext*          aPresContext,
@@ -240,7 +241,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   void GetParentContent(nsIContent** aContent);
@@ -338,7 +339,7 @@ NS_IMETHODIMP
 nsHTMLFrameOuterFrame::Init(nsIPresContext*  aPresContext,
                             nsIContent*      aContent,
                             nsIFrame*        aParent,
-                            nsIStyleContext* aContext,
+                            nsStyleContext*  aContext,
                             nsIFrame*        aPrevInFlow)
 {
   mPresContext = aPresContext;
@@ -412,16 +413,10 @@ nsHTMLFrameOuterFrame::Init(nsIPresContext*  aPresContext,
     mFrames.SetFrames(firstChild);
     // Resolve the style context for the inner frame
     nsresult rv = NS_OK;
-    nsIStyleContext *innerStyleContext = nsnull;
-    rv = aPresContext->ResolveStyleContextFor(mContent, mStyleContext,
-                                              &innerStyleContext);
-    if (NS_SUCCEEDED(rv)) {
-      rv = firstChild->Init(aPresContext, mContent, this, innerStyleContext, nsnull);
-      // have to release the context: Init does its own AddRef...
-      NS_RELEASE(innerStyleContext);
-    } else {
-      NS_WARNING( "Error resolving style for InnerFrame in nsHTMLFrameOuterFrame");
-    }
+    nsRefPtr<nsStyleContext> innerStyleContext;
+    innerStyleContext = aPresContext->ResolveStyleContextFor(mContent,
+                                                             mStyleContext);
+    rv = firstChild->Init(aPresContext, mContent, this, innerStyleContext, nsnull);
     if (NS_FAILED(rv)){
       NS_WARNING( "Error initializing InnerFrame in nsHTMLFrameOuterFrame");
       return rv;
@@ -1192,7 +1187,7 @@ NS_IMETHODIMP
 nsHTMLFrameInnerFrame::Init(nsIPresContext*  aPresContext,
                             nsIContent*      aContent,
                             nsIFrame*        aParent,
-                            nsIStyleContext* aContext,
+                            nsStyleContext*  aContext,
                             nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsLeafFrame::Init(aPresContext, aContent, aParent, aContext,
diff --git a/mozilla/layout/generic/nsFrameSetFrame.cpp b/mozilla/layout/generic/nsFrameSetFrame.cpp
index 013eff7993a..ca734b8be83 100644
--- a/mozilla/layout/generic/nsFrameSetFrame.cpp
+++ b/mozilla/layout/generic/nsFrameSetFrame.cpp
@@ -38,7 +38,7 @@
 #include "nsIScrollableView.h"
 #include "nsStyleCoord.h"
 #include "nsStyleConsts.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIDocumentLoader.h"
 #include "nsHTMLParts.h"
 #include "nsILookAndFeel.h"
@@ -54,6 +54,7 @@
 #include "nsINameSpaceManager.h"
 #include "nsCSSPseudoElements.h"
 #include "nsCSSAnonBoxes.h"
+#include "nsAutoPtr.h"
 
 // masks for mEdgeVisibility
 #define LEFT_VIS   0x0001
@@ -317,7 +318,7 @@ NS_IMETHODIMP
 nsHTMLFramesetFrame::Init(nsIPresContext*  aPresContext,
                           nsIContent*      aContent,
                           nsIFrame*        aParent,
-                          nsIStyleContext* aContext,
+                          nsStyleContext*  aContext,
                           nsIFrame*        aPrevInFlow)
 {
   nsHTMLContainerFrame::Init(aPresContext, aContent, aParent,
@@ -408,11 +409,10 @@ nsHTMLFramesetFrame::Init(nsIPresContext*  aPresContext,
     nsCOMPtr<nsIAtom> tag;
     child->GetTag(*getter_AddRefs(tag));
     if (tag == nsHTMLAtoms::frameset || tag == nsHTMLAtoms::frame) {
-      nsCOMPtr<nsIStyleContext> kidSC;
+      nsRefPtr<nsStyleContext> kidSC;
       nsresult result;
 
-      aPresContext->ResolveStyleContextFor(child, mStyleContext,
-                                           getter_AddRefs(kidSC));
+      kidSC = aPresContext->ResolveStyleContextFor(child, mStyleContext);
       if (tag == nsHTMLAtoms::frameset) {
         result = NS_NewHTMLFramesetFrame(shell, &frame);
 
@@ -453,10 +453,10 @@ nsHTMLFramesetFrame::Init(nsIPresContext*  aPresContext,
     // XXX the blank frame is using the content of its parent - at some point it 
     // should just have null content, if we support that
     nsHTMLFramesetBlankFrame* blankFrame = new (shell.get()) nsHTMLFramesetBlankFrame;
-    nsCOMPtr<nsIStyleContext> pseudoStyleContext;
-    aPresContext->ResolvePseudoStyleContextFor(nsnull,
-                            nsCSSAnonBoxes::framesetBlank, mStyleContext,
-                            getter_AddRefs(pseudoStyleContext));
+    nsRefPtr<nsStyleContext> pseudoStyleContext;
+    pseudoStyleContext = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                    nsCSSAnonBoxes::framesetBlank,
+                                                                    mStyleContext);
     if(blankFrame)
       blankFrame->Init(aPresContext, mContent, this, pseudoStyleContext, nsnull);
    
@@ -1080,12 +1080,11 @@ nsHTMLFramesetFrame::Reflow(nsIPresContext*          aPresContext,
       offset.y += lastSize.height;
       if (firstTime) { // create horizontal border
         borderFrame = new (shell.get()) nsHTMLFramesetBorderFrame(borderWidth, PR_FALSE, PR_FALSE);
-        nsIStyleContext* pseudoStyleContext;
-        aPresContext->ResolvePseudoStyleContextFor(mContent, nsCSSPseudoElements::horizontalFramesetBorder,
-                                                   mStyleContext,
-                                                   &pseudoStyleContext);
+        nsRefPtr<nsStyleContext> pseudoStyleContext;
+        pseudoStyleContext = aPresContext->ResolvePseudoStyleContextFor(mContent,
+                                                                        nsCSSPseudoElements::horizontalFramesetBorder,
+                                                                        mStyleContext);
         borderFrame->Init(aPresContext, mContent, this, pseudoStyleContext, nsnull);
-        NS_RELEASE(pseudoStyleContext);
 
         mChildCount++;
         lastChild->SetNextSibling(borderFrame);
@@ -1108,12 +1107,11 @@ nsHTMLFramesetFrame::Reflow(nsIPresContext*          aPresContext,
         if (0 == cellIndex.y) { // in 1st row
           if (firstTime) { // create vertical border
             borderFrame = new (shell.get()) nsHTMLFramesetBorderFrame(borderWidth, PR_TRUE, PR_FALSE);
-            nsIStyleContext* pseudoStyleContext;
-            aPresContext->ResolvePseudoStyleContextFor(mContent, nsCSSPseudoElements::verticalFramesetBorder,
-                                                       mStyleContext,
-                                                       &pseudoStyleContext);
+            nsRefPtr<nsStyleContext> pseudoStyleContext;
+            pseudoStyleContext = aPresContext->ResolvePseudoStyleContextFor(mContent,
+                                                                            nsCSSPseudoElements::verticalFramesetBorder,
+                                                                            mStyleContext);
             borderFrame->Init(aPresContext, mContent, this, pseudoStyleContext, nsnull);
-            NS_RELEASE(pseudoStyleContext);
 
             mChildCount++;
             lastChild->SetNextSibling(borderFrame);
diff --git a/mozilla/layout/generic/nsFrameSetFrame.h b/mozilla/layout/generic/nsFrameSetFrame.h
index 22abd4f6892..6426af8a062 100644
--- a/mozilla/layout/generic/nsFrameSetFrame.h
+++ b/mozilla/layout/generic/nsFrameSetFrame.h
@@ -120,7 +120,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   static PRBool  gDragInProgress;
diff --git a/mozilla/layout/generic/nsGfxScrollFrame.cpp b/mozilla/layout/generic/nsGfxScrollFrame.cpp
index ac4b86ef12e..e8b129923a4 100644
--- a/mozilla/layout/generic/nsGfxScrollFrame.cpp
+++ b/mozilla/layout/generic/nsGfxScrollFrame.cpp
@@ -470,7 +470,7 @@ NS_IMETHODIMP
 nsGfxScrollFrame::Init(nsIPresContext*  aPresContext,
                     nsIContent*      aContent,
                     nsIFrame*        aParent,
-                    nsIStyleContext* aStyleContext,
+                    nsStyleContext*  aStyleContext,
                     nsIFrame*        aPrevInFlow)
 {
   mPresContext = aPresContext;
diff --git a/mozilla/layout/generic/nsGfxScrollFrame.h b/mozilla/layout/generic/nsGfxScrollFrame.h
index 00f3e2c6566..5b0a31932a4 100644
--- a/mozilla/layout/generic/nsGfxScrollFrame.h
+++ b/mozilla/layout/generic/nsGfxScrollFrame.h
@@ -64,7 +64,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   virtual ~nsGfxScrollFrame();
diff --git a/mozilla/layout/generic/nsHTMLContainerFrame.cpp b/mozilla/layout/generic/nsHTMLContainerFrame.cpp
index 80837fe114e..874e4f7bfd2 100644
--- a/mozilla/layout/generic/nsHTMLContainerFrame.cpp
+++ b/mozilla/layout/generic/nsHTMLContainerFrame.cpp
@@ -38,7 +38,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresContext.h"
 #include "nsIPresShell.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIContent.h"
 #include "nsLayoutAtoms.h"
@@ -188,10 +188,9 @@ nsHTMLContainerFrame::GetTextDecorations(nsIPresContext* aPresContext,
     for (nsIFrame *frame = this; frame && decorMask; frame->GetParent(&frame)) {
       // find text-decorations.  "Inherit" from parent *block* frames
 
-      nsCOMPtr<nsIStyleContext> styleContext;
-      frame->GetStyleContext(getter_AddRefs(styleContext));
+      nsStyleContext* styleContext = frame->GetStyleContext();
       const nsStyleDisplay* styleDisplay;
-      ::GetStyleData(styleContext.get(), &styleDisplay);
+      ::GetStyleData(styleContext, &styleDisplay);
       if (!styleDisplay->IsBlockLevel() &&
           styleDisplay->mDisplay != NS_STYLE_DISPLAY_TABLE_CELL) {
         // If an inline frame is discovered while walking up the tree,
@@ -200,12 +199,12 @@ nsHTMLContainerFrame::GetTextDecorations(nsIPresContext* aPresContext,
         break;
       }
 
-      ::GetStyleData(styleContext.get(), &styleText);
+      ::GetStyleData(styleContext, &styleText);
       PRUint8 decors = decorMask & styleText->mTextDecoration;
       if (decors) {
         // A *new* text-decoration is found.
         const nsStyleColor* styleColor;
-        ::GetStyleData(styleContext.get(), &styleColor);
+        ::GetStyleData(styleContext, &styleColor);
 
         if (NS_STYLE_TEXT_DECORATION_UNDERLINE & decors) {
           aUnderColor = styleColor->mColor;
@@ -605,7 +604,7 @@ nsHTMLContainerFrame::ReparentFrameViewList(nsIPresContext* aPresContext,
 nsresult
 nsHTMLContainerFrame::CreateViewForFrame(nsIPresContext* aPresContext,
                                          nsIFrame* aFrame,
-                                         nsIStyleContext* aStyleContext,
+                                         nsStyleContext* aStyleContext,
                                          nsIFrame* aContentParentFrame,
                                          PRBool aForce)
 {
diff --git a/mozilla/layout/generic/nsHTMLContainerFrame.h b/mozilla/layout/generic/nsHTMLContainerFrame.h
index 9286da05dc0..2b45df58bb9 100644
--- a/mozilla/layout/generic/nsHTMLContainerFrame.h
+++ b/mozilla/layout/generic/nsHTMLContainerFrame.h
@@ -94,7 +94,7 @@ public:
    */
   static nsresult CreateViewForFrame(nsIPresContext* aPresContext,
                                      nsIFrame* aFrame,
-                                     nsIStyleContext* aStyleContext,
+                                     nsStyleContext* aStyleContext,
                                      nsIFrame* aContentParentFrame,
                                      PRBool aForce);
 
diff --git a/mozilla/layout/generic/nsHTMLFrame.cpp b/mozilla/layout/generic/nsHTMLFrame.cpp
index b5324332a0d..549422003b5 100644
--- a/mozilla/layout/generic/nsHTMLFrame.cpp
+++ b/mozilla/layout/generic/nsHTMLFrame.cpp
@@ -41,7 +41,7 @@
 #include "nsIDocument.h"
 #include "nsReflowPath.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsViewsCID.h"
 #include "nsIView.h"
 #include "nsIViewManager.h"
@@ -95,7 +95,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow);
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
 
@@ -223,7 +223,7 @@ NS_IMETHODIMP
 CanvasFrame::Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsHTMLContainerFrame::Init(aPresContext,aContent,aParent,aContext,aPrevInFlow);
diff --git a/mozilla/layout/generic/nsHTMLReflowState.cpp b/mozilla/layout/generic/nsHTMLReflowState.cpp
index 3e0d92bdbad..35b5cbf03c5 100644
--- a/mozilla/layout/generic/nsHTMLReflowState.cpp
+++ b/mozilla/layout/generic/nsHTMLReflowState.cpp
@@ -621,8 +621,7 @@ GetNearestContainingBlock(nsIFrame* aFrame, nsMargin& aContentArea)
     // it's percentage based (for example) then just ignore it
     nsStyleBorderPadding  bPad;
     nsMargin              borderPadding;
-    nsCOMPtr<nsIStyleContext> styleContext;
-    aFrame->GetStyleContext(getter_AddRefs(styleContext));
+    nsStyleContext* styleContext = aFrame->GetStyleContext();
     styleContext->GetBorderPaddingFor(bPad);
     if (bPad.GetBorderPadding(borderPadding)) {
       aContentArea.left += borderPadding.left;
@@ -2317,7 +2316,7 @@ GetNormalLineHeight(nsIFontMetrics* aFontMetrics)
 static nscoord
 ComputeLineHeight(nsIPresContext* aPresContext,
                   nsIRenderingContext* aRenderingContext,
-                  nsIStyleContext* aStyleContext)
+                  nsStyleContext* aStyleContext)
 {
   NS_PRECONDITION(nsnull != aRenderingContext, "no rendering context");
 
@@ -2377,8 +2376,7 @@ nsHTMLReflowState::CalcLineHeight(nsIPresContext* aPresContext,
                                   nsIFrame* aFrame)
 {
   nscoord lineHeight = -1;
-  nsCOMPtr<nsIStyleContext> sc;
-  aFrame->GetStyleContext(getter_AddRefs(sc));
+  nsStyleContext* sc = aFrame->GetStyleContext();
   if (sc) {
     lineHeight = ComputeLineHeight(aPresContext, aRenderingContext, sc);
   }
@@ -2427,8 +2425,7 @@ nsHTMLReflowState::ComputeHorizontalValue(nscoord aContainingBlockWidth,
       // pretend its zero...
     }
     else {
-      nsCOMPtr<nsIStyleContext> styleContext;
-      frame->GetStyleContext(getter_AddRefs(styleContext));
+      nsStyleContext* styleContext = frame->GetStyleContext();
       SetFontFromStyle(rendContext, styleContext);
       nscoord fontWidth;
       rendContext->GetWidth('M', fontWidth);
diff --git a/mozilla/layout/generic/nsIAnonymousContentCreator.h b/mozilla/layout/generic/nsIAnonymousContentCreator.h
index 6e563b221f2..2f0b0fa982a 100644
--- a/mozilla/layout/generic/nsIAnonymousContentCreator.h
+++ b/mozilla/layout/generic/nsIAnonymousContentCreator.h
@@ -46,7 +46,6 @@
 class nsIPresContext;
 class nsISupportsArray;
 class nsIAtom;
-class nsIStyleContext;
 class nsIFrame;
 
 
diff --git a/mozilla/layout/generic/nsIFrame.h b/mozilla/layout/generic/nsIFrame.h
index adb6fceba85..2850ae5976f 100644
--- a/mozilla/layout/generic/nsIFrame.h
+++ b/mozilla/layout/generic/nsIFrame.h
@@ -47,7 +47,7 @@
 #include "nsISupports.h"
 #include "nsEvent.h"
 #include "nsStyleStruct.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIContent.h"
 
 /**
@@ -418,7 +418,7 @@ public:
   NS_IMETHOD  Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        aPrevInFlow) = 0;
 
   /**
@@ -553,24 +553,21 @@ public:
   NS_IMETHOD GetOffsets(PRInt32 &start, PRInt32 &end) const = 0;
 
   /**
-   * Get the style context associated with this frame. Note that GetStyleContext()
-   * adds a reference to the style context so the caller must do a release.
+   * Get the style context associated with this frame.
    *
-   * @see nsISupports#Release()
    */
-  nsresult GetStyleContext(nsIStyleContext** aStyleContext) const { 
-    *aStyleContext = mStyleContext; NS_IF_ADDREF(*aStyleContext); return NS_OK;
-  }
-  nsresult SetStyleContext(nsIPresContext*  aPresContext, nsIStyleContext* aContext) { 
+  nsStyleContext* GetStyleContext() const { return mStyleContext; }
+  void SetStyleContext(nsIPresContext* aPresContext, nsStyleContext* aContext)
+  { 
     if (aContext != mStyleContext) {
-      NS_IF_RELEASE(mStyleContext);
-      if (nsnull != aContext) {
-        mStyleContext = aContext;
-        NS_ADDREF(aContext);
+      if (mStyleContext)
+        mStyleContext->Release();
+      mStyleContext = aContext;
+      if (aContext) {
+        aContext->AddRef();
         DidSetStyleContext(aPresContext);
       }
     }
-    return NS_OK;
   }
 
   // Style post processing hook
@@ -596,13 +593,6 @@ public:
   }
 #endif
 
-  // Fill a style struct with data
-  nsresult GetStyle(nsStyleStructID aSID, const nsStyleStruct** aStruct) const {
-    NS_ASSERTION(mStyleContext, "No style context found!");
-    mStyleContext->GetStyle(aSID, aStruct);
-    return NS_OK;
-  }
-
   // Utility function: more convenient than 2 calls to GetStyleData to get border and padding
   NS_IMETHOD  CalcBorderPadding(nsMargin& aBorderPadding) const = 0;
 
@@ -616,10 +606,10 @@ public:
    * The indicies must be consecutive and implementations MUST return an 
    * NS_ERROR_INVALID_ARG if asked for an index that is out of range.
    */
-  NS_IMETHOD  GetAdditionalStyleContext(PRInt32 aIndex, 
-                                        nsIStyleContext** aStyleContext) const = 0;
-  NS_IMETHOD  SetAdditionalStyleContext(PRInt32 aIndex, 
-                                        nsIStyleContext* aStyleContext) = 0;
+  virtual nsStyleContext* GetAdditionalStyleContext(PRInt32 aIndex) const = 0;
+
+  virtual void SetAdditionalStyleContext(PRInt32 aIndex,
+                                         nsStyleContext* aStyleContext) = 0;
 
   /**
    * Accessor functions for geometric parent
@@ -1239,7 +1229,7 @@ protected:
   // Members
   nsRect           mRect;
   nsIContent*      mContent;
-  nsIStyleContext* mStyleContext;
+  nsStyleContext*  mStyleContext;
   nsIFrame*        mParent;
   nsIFrame*        mNextSibling;  // singly-linked list of frames
   nsFrameState     mState;
@@ -1250,7 +1240,7 @@ private:
 };
 
 // typesafe way to access style data.  See comment in nsStyleStruct.h
-// and also overloaded function in nsIStyleContext.h
+// and also overloaded function in nsStyleContext.h
 template <class T>
 inline void
 GetStyleData(nsIFrame* aFrame, const T** aStyleStruct)
diff --git a/mozilla/layout/generic/nsImageFrame.cpp b/mozilla/layout/generic/nsImageFrame.cpp
index fb3282cd91f..280c90dc0f8 100644
--- a/mozilla/layout/generic/nsImageFrame.cpp
+++ b/mozilla/layout/generic/nsImageFrame.cpp
@@ -48,7 +48,7 @@
 #include "nsIHTMLContent.h"
 #include "nsIDocument.h"
 #include "nsINodeInfo.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsImageMap.h"
 #include "nsILinkHandler.h"
@@ -304,7 +304,7 @@ NS_IMETHODIMP
 nsImageFrame::Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        aPrevInFlow)
 {
   nsresult  rv = nsSplittableFrame::Init(aPresContext, aContent, aParent,
@@ -1296,7 +1296,7 @@ nsImageFrame::Paint(nsIPresContext*      aPresContext,
     // inline-level or block-level, respectively.  (See CSS2 9.5, which
     // is the rationale for paint layers.)
     const nsStyleDisplay *display;
-    ::GetStyleData(NS_STATIC_CAST(nsIStyleContext*, mStyleContext), &display);
+    ::GetStyleData(mStyleContext, &display);
     nsFramePaintLayer backgroundLayer = display->IsBlockLevel()
                                             ? NS_FRAME_PAINT_LAYER_BACKGROUND
                                             : NS_FRAME_PAINT_LAYER_FOREGROUND;
diff --git a/mozilla/layout/generic/nsImageFrame.h b/mozilla/layout/generic/nsImageFrame.h
index 3894960a5bd..fc1093f250e 100644
--- a/mozilla/layout/generic/nsImageFrame.h
+++ b/mozilla/layout/generic/nsImageFrame.h
@@ -96,7 +96,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   NS_IMETHOD Paint(nsIPresContext*      aPresContext,
                    nsIRenderingContext& aRenderingContext,
diff --git a/mozilla/layout/generic/nsInlineFrame.cpp b/mozilla/layout/generic/nsInlineFrame.cpp
index 1d38da366f3..a9bfa4786c7 100644
--- a/mozilla/layout/generic/nsInlineFrame.cpp
+++ b/mozilla/layout/generic/nsInlineFrame.cpp
@@ -39,7 +39,7 @@
 #include "nsBlockFrame.h"
 #include "nsHTMLAtoms.h"
 #include "nsHTMLParts.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIPresShell.h"
 #include "nsIPresContext.h"
 #include "nsIRenderingContext.h"
@@ -48,6 +48,7 @@
 #include "nsLayoutAtoms.h"
 #include "nsCSSAnonBoxes.h"
 #include "nsReflowPath.h"
+#include "nsAutoPtr.h"
 #ifdef ACCESSIBILITY
 #include "nsIServiceManager.h"
 #include "nsIAccessibilityService.h"
@@ -943,7 +944,7 @@ NS_IMETHODIMP nsInlineFrame::GetAccessible(nsIAccessible** aAccessible)
 
 static void
 ReParentChildListStyle(nsIPresContext* aPresContext,
-                       nsIStyleContext* aParentStyleContext,
+                       nsStyleContext* aParentStyleContext,
                        nsFrameList& aFrameList)
 {
   nsIFrame* kid = aFrameList.FirstChild();
@@ -1090,26 +1091,22 @@ nsFirstLineFrame::Reflow(nsIPresContext* aPresContext,
       // proper parent context.
       nsIFrame* parentFrame;
       first->GetParent(&parentFrame);
-      nsIStyleContext* parentContext;
-      parentFrame->GetStyleContext(&parentContext);
+      nsStyleContext* parentContext = parentFrame->GetStyleContext();
       if (parentContext) {
         // Create a new style context that is a child of the parent
         // style context thus removing the :first-line style. This way
         // we behave as if an anonymous (unstyled) span was the child
         // of the parent frame.
-        nsIStyleContext* newSC;
-        aPresContext->ResolvePseudoStyleContextFor(nsnull,
-                      nsCSSAnonBoxes::mozLineFrame, parentContext, &newSC);
+        nsRefPtr<nsStyleContext> newSC = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                                    nsCSSAnonBoxes::mozLineFrame,
+                                                                                    parentContext);
         if (newSC) {
           // Switch to the new style context.
           SetStyleContext(aPresContext, newSC);
 
           // Re-resolve all children
           ReParentChildListStyle(aPresContext, mStyleContext, mFrames);
-
-          NS_RELEASE(newSC);
         }
-        NS_RELEASE(parentContext);
       }
     }
   }
diff --git a/mozilla/layout/generic/nsLineLayout.cpp b/mozilla/layout/generic/nsLineLayout.cpp
index 1096a940843..c3507d52a10 100644
--- a/mozilla/layout/generic/nsLineLayout.cpp
+++ b/mozilla/layout/generic/nsLineLayout.cpp
@@ -45,7 +45,7 @@
 #include "nsStyleConsts.h"
 #include "nsHTMLContainerFrame.h"
 #include "nsSpaceManager.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIPresContext.h"
 #include "nsIFontMetrics.h"
 #include "nsIRenderingContext.h"
@@ -2097,8 +2097,7 @@ nsLineLayout::VerticalAlignFrames(PerSpanData* psd)
   nsIFrame* spanFrame = spanFramePFD->mFrame;
 
   // Get the parent frame's font for all of the frames in this span
-  nsCOMPtr<nsIStyleContext> styleContext;
-  spanFrame->GetStyleContext(getter_AddRefs(styleContext));
+  nsStyleContext* styleContext = spanFrame->GetStyleContext();
   nsIRenderingContext* rc = mBlockReflowState->rendContext;
   SetFontFromStyle(mBlockReflowState->rendContext, styleContext);
   nsCOMPtr<nsIFontMetrics> fm;
diff --git a/mozilla/layout/generic/nsObjectFrame.cpp b/mozilla/layout/generic/nsObjectFrame.cpp
index ee1b9d74308..e92e3b22ef5 100644
--- a/mozilla/layout/generic/nsObjectFrame.cpp
+++ b/mozilla/layout/generic/nsObjectFrame.cpp
@@ -118,7 +118,7 @@
 #include "nsIPrefService.h"
 
 // XXX For temporary paint code
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 
 // For mime types
 #include "nsMimeTypes.h"
@@ -577,7 +577,7 @@ NS_IMETHODIMP
 nsObjectFrame::Init(nsIPresContext*  aPresContext,
                     nsIContent*      aContent,
                     nsIFrame*        aParent,
-                    nsIStyleContext* aContext,
+                    nsStyleContext*  aContext,
                     nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsObjectFrameSuper::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/generic/nsObjectFrame.h b/mozilla/layout/generic/nsObjectFrame.h
index b931fdc351c..f924471bc6d 100644
--- a/mozilla/layout/generic/nsObjectFrame.h
+++ b/mozilla/layout/generic/nsObjectFrame.h
@@ -64,7 +64,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   NS_IMETHOD Reflow(nsIPresContext*          aPresContext,
                     nsHTMLReflowMetrics&     aDesiredSize,
diff --git a/mozilla/layout/generic/nsPageContentFrame.cpp b/mozilla/layout/generic/nsPageContentFrame.cpp
index 8d6d490815d..202746c761e 100644
--- a/mozilla/layout/generic/nsPageContentFrame.cpp
+++ b/mozilla/layout/generic/nsPageContentFrame.cpp
@@ -38,7 +38,6 @@
 #include "nsHTMLParts.h"
 #include "nsIContent.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
 #include "nsIRenderingContext.h"
 #include "nsHTMLAtoms.h"
 #include "nsLayoutAtoms.h"
diff --git a/mozilla/layout/generic/nsPageFrame.cpp b/mozilla/layout/generic/nsPageFrame.cpp
index 07c544b42ab..817d8956eb8 100644
--- a/mozilla/layout/generic/nsPageFrame.cpp
+++ b/mozilla/layout/generic/nsPageFrame.cpp
@@ -38,7 +38,7 @@
 #include "nsHTMLParts.h"
 #include "nsIContent.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIRenderingContext.h"
 #include "nsHTMLAtoms.h"
 #include "nsLayoutAtoms.h"
diff --git a/mozilla/layout/generic/nsPlaceholderFrame.cpp b/mozilla/layout/generic/nsPlaceholderFrame.cpp
index 49820fca39e..83ee0f7b7a1 100644
--- a/mozilla/layout/generic/nsPlaceholderFrame.cpp
+++ b/mozilla/layout/generic/nsPlaceholderFrame.cpp
@@ -39,7 +39,6 @@
 #include "nsIContent.h"
 #include "nsIPresContext.h"
 #include "nsIRenderingContext.h"
-#include "nsIStyleContext.h"
 #include "nsLayoutAtoms.h"
 
 nsresult
diff --git a/mozilla/layout/generic/nsSplittableFrame.cpp b/mozilla/layout/generic/nsSplittableFrame.cpp
index abf0864dc48..2e201b1292d 100644
--- a/mozilla/layout/generic/nsSplittableFrame.cpp
+++ b/mozilla/layout/generic/nsSplittableFrame.cpp
@@ -37,14 +37,14 @@
 #include "nsSplittableFrame.h"
 #include "nsIContent.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsISizeOfHandler.h"
 
 NS_IMETHODIMP
 nsSplittableFrame::Init(nsIPresContext*  aPresContext,
                         nsIContent*      aContent,
                         nsIFrame*        aParent,
-                        nsIStyleContext* aContext,
+                        nsStyleContext*  aContext,
                         nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
diff --git a/mozilla/layout/generic/nsSplittableFrame.h b/mozilla/layout/generic/nsSplittableFrame.h
index cb402792b03..f2db6b93a61 100644
--- a/mozilla/layout/generic/nsSplittableFrame.h
+++ b/mozilla/layout/generic/nsSplittableFrame.h
@@ -46,7 +46,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   
   NS_IMETHOD  IsSplittable(nsSplittableType& aIsSplittable) const;
diff --git a/mozilla/layout/generic/nsTextFrame.cpp b/mozilla/layout/generic/nsTextFrame.cpp
index 8552b4f678e..9864ce512d5 100644
--- a/mozilla/layout/generic/nsTextFrame.cpp
+++ b/mozilla/layout/generic/nsTextFrame.cpp
@@ -50,7 +50,7 @@
 #include "nsIPresContext.h"
 #include "nsIContent.h"
 #include "nsStyleConsts.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsCoord.h"
 #include "nsIFontMetrics.h"
 #include "nsIRenderingContext.h"
@@ -91,6 +91,7 @@
 #include "nsIAccessibilityService.h"
 #endif
 #include "nsGUIEvent.h"
+#include "nsAutoPtr.h"
 
 #ifdef IBMBIDI
 #include "nsBidiFrames.h"
@@ -536,7 +537,7 @@ public:
 
     TextStyle(nsIPresContext* aPresContext,
               nsIRenderingContext& aRenderingContext,
-              nsIStyleContext* sc)
+              nsStyleContext* sc)
     {
     mFont = nsnull;
     mText = nsnull;
@@ -679,7 +680,7 @@ public:
                                         PRUnichar* aBuffer, PRInt32 aLength, PRInt32 aNumSpaces);
 
   void PaintTextDecorations(nsIRenderingContext& aRenderingContext,
-                            nsIStyleContext* aStyleContext,
+                            nsStyleContext* aStyleContext,
                             nsIPresContext* aPresContext,
                             TextStyle& aStyle,
                             nscoord aX, nscoord aY, nscoord aWidth,
@@ -691,12 +692,12 @@ public:
 
   void PaintTextSlowly(nsIPresContext* aPresContext,
                        nsIRenderingContext& aRenderingContext,
-                       nsIStyleContext* aStyleContext,
+                       nsStyleContext* aStyleContext,
                        TextStyle& aStyle,
                        nscoord aX, nscoord aY);
 
   void RenderString(nsIRenderingContext& aRenderingContext,
-                    nsIStyleContext* aStyleContext,
+                    nsStyleContext* aStyleContext,
                     nsIPresContext* aPresContext,
                     TextStyle& aStyle,
                     PRUnichar* aBuffer, PRInt32 aLength,
@@ -748,13 +749,13 @@ public:
 
   void PaintUnicodeText(nsIPresContext* aPresContext,
                         nsIRenderingContext& aRenderingContext,
-                        nsIStyleContext* aStyleContext,
+                        nsStyleContext* aStyleContext,
                         TextStyle& aStyle,
                         nscoord dx, nscoord dy);
 
   void PaintAsciiText(nsIPresContext* aPresContext,
                       nsIRenderingContext& aRenderingContext,
-                      nsIStyleContext* aStyleContext,
+                      nsStyleContext* aStyleContext,
                       TextStyle& aStyle,
                       nscoord dx, nscoord dy);
 
@@ -874,7 +875,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
@@ -901,7 +902,7 @@ NS_IMETHODIMP
 nsContinuingTextFrame::Init(nsIPresContext*  aPresContext,
                             nsIContent*      aContent,
                             nsIFrame*        aParent,
-                            nsIStyleContext* aContext,
+                            nsStyleContext*  aContext,
                             nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
@@ -1006,7 +1007,7 @@ public:
   DrawSelectionIterator(nsIContent *aContent, const SelectionDetails *aSelDetails, PRUnichar *aText,
                         PRUint32 aTextLength, nsTextFrame::TextStyle &aTextStyle,
                         PRInt16 aSelectionStatus, nsIPresContext *aPresContext,
-                        nsIStyleContext *aStyleContext);
+                        nsStyleContext *aStyleContext);
   ~DrawSelectionIterator();
   PRBool      First();
   PRBool      Next();
@@ -1051,7 +1052,7 @@ DrawSelectionIterator::DrawSelectionIterator(nsIContent *aContent,
                                              nsTextFrame::TextStyle &aTextStyle, 
                                              PRInt16 aSelectionStatus, 
                                              nsIPresContext *aPresContext,
-                                             nsIStyleContext *aStyleContext)
+                                             nsStyleContext *aStyleContext)
                                              :mOldStyle(aTextStyle)
 {
     mDetails = aSelDetails;
@@ -1065,13 +1066,13 @@ DrawSelectionIterator::DrawSelectionIterator(nsIContent *aContent,
     mSelectionPseudoBGIsTransparent = PR_FALSE;
 
     if (aContent) {
-      nsIStyleContext *sc = nsnull;
       nsCOMPtr<nsIContent> parentContent;
       aContent->GetParent(*getter_AddRefs(parentContent));
-      aPresContext->ProbePseudoStyleContextFor(parentContent,
-  					     nsCSSPseudoElements::mozSelection,
-  					     aStyleContext, &sc);
-      if (nsnull != sc) {
+      nsRefPtr<nsStyleContext> sc;
+      sc = aPresContext->ProbePseudoStyleContextFor(parentContent,
+						    nsCSSPseudoElements::mozSelection,
+						    aStyleContext);
+      if (sc) {
         mSelectionPseudoStyle = PR_TRUE;
         const nsStyleBackground* bg = (const nsStyleBackground*)sc->GetStyleData(eStyleStruct_Background);
         mSelectionPseudoBGIsTransparent = PRBool(bg->mBackgroundFlags & NS_STYLE_BG_COLOR_TRANSPARENT);
@@ -1079,7 +1080,6 @@ DrawSelectionIterator::DrawSelectionIterator(nsIContent *aContent,
           mSelectionPseudoBGcolor = bg->mBackgroundColor;
         const nsStyleColor* color =(const nsStyleColor*) sc->GetStyleData(eStyleStruct_Color);
         mSelectionPseudoFGcolor = color->mColor;
-        NS_RELEASE(sc);
       }
     }
 
@@ -1510,7 +1510,7 @@ nsTextFrame::Paint(nsIPresContext*      aPresContext,
   if ((0 != (mState & TEXT_BLINK_ON)) && nsBlinkTimer::GetBlinkIsOff()) {
     return NS_OK;
   }
-  nsIStyleContext* sc = mStyleContext;
+  nsStyleContext* sc = mStyleContext;
   PRBool isVisible;
   if (NS_SUCCEEDED(IsVisibleForPainting(aPresContext, aRenderingContext, PR_TRUE, &isVisible)) && isVisible) {
     TextStyle ts(aPresContext, aRenderingContext, mStyleContext);
@@ -1822,7 +1822,7 @@ RenderSelectionCursor(nsIRenderingContext& aRenderingContext,
 
 void 
 nsTextFrame::PaintTextDecorations(nsIRenderingContext& aRenderingContext,
-                                  nsIStyleContext* aStyleContext,
+                                  nsStyleContext* aStyleContext,
                                   nsIPresContext* aPresContext,
                                   TextStyle& aTextStyle,
                                   nscoord aX, nscoord aY, nscoord aWidth,
@@ -1849,19 +1849,19 @@ nsTextFrame::PaintTextDecorations(nsIRenderingContext& aRenderingContext,
     PRUint8 decorMask = NS_STYLE_TEXT_DECORATION_UNDERLINE | 
                         NS_STYLE_TEXT_DECORATION_OVERLINE |
                         NS_STYLE_TEXT_DECORATION_LINE_THROUGH;    
-    nsCOMPtr<nsIStyleContext> context = aStyleContext;
+    nsStyleContext* context = aStyleContext;
     PRBool hasDecorations = context->HasTextDecorations();
 
     while (hasDecorations) {
       const nsStyleTextReset* styleText;
-      ::GetStyleData(context.get(), &styleText);
+      ::GetStyleData(context, &styleText);
       if (!useOverride && 
           (NS_STYLE_TEXT_DECORATION_OVERRIDE_ALL & 
            styleText->mTextDecoration)) {
         // This handles the <a href="blah.html"><font color="green">La 
         // la la</font></a> case. The link underline should be green.
         const nsStyleColor* styleColor;
-        ::GetStyleData(context.get(), &styleColor);
+        ::GetStyleData(context, &styleColor);
         useOverride = PR_TRUE;
         overrideColor = styleColor->mColor;          
       }
@@ -1869,7 +1869,7 @@ nsTextFrame::PaintTextDecorations(nsIRenderingContext& aRenderingContext,
       PRUint8 useDecorations = decorMask & styleText->mTextDecoration;
       if (useDecorations) {// a decoration defined here
         const nsStyleColor* styleColor;
-        ::GetStyleData(context.get(), &styleColor);
+        ::GetStyleData(context, &styleColor);
     
         if (NS_STYLE_TEXT_DECORATION_UNDERLINE & useDecorations) {
           underColor = useOverride ? overrideColor : styleColor->mColor;
@@ -2293,7 +2293,7 @@ nsTextFrame::IsVisibleForPainting(nsIPresContext *     aPresContext,
 void
 nsTextFrame::PaintUnicodeText(nsIPresContext* aPresContext,
                               nsIRenderingContext& aRenderingContext,
-                              nsIStyleContext* aStyleContext,
+                              nsStyleContext* aStyleContext,
                               TextStyle& aTextStyle,
                               nscoord dx, nscoord dy)
 {
@@ -2698,7 +2698,7 @@ nsTextFrame::GetPositionSlowly(nsIPresContext* aPresContext,
 
 void
 nsTextFrame::RenderString(nsIRenderingContext& aRenderingContext,
-                          nsIStyleContext* aStyleContext,
+                          nsStyleContext* aStyleContext,
                           nsIPresContext* aPresContext,
                           TextStyle& aTextStyle,
                           PRUnichar* aBuffer, PRInt32 aLength,
@@ -3010,7 +3010,7 @@ nsTextFrame::ComputeExtraJustificationSpacing(nsIRenderingContext& aRenderingCon
 void
 nsTextFrame::PaintTextSlowly(nsIPresContext* aPresContext,
                              nsIRenderingContext& aRenderingContext,
-                             nsIStyleContext* aStyleContext,
+                             nsStyleContext* aStyleContext,
                              TextStyle& aTextStyle,
                              nscoord dx, nscoord dy)
 {
@@ -3197,7 +3197,7 @@ nsTextFrame::PaintTextSlowly(nsIPresContext* aPresContext,
 void
 nsTextFrame::PaintAsciiText(nsIPresContext* aPresContext,
                             nsIRenderingContext& aRenderingContext,
-                            nsIStyleContext* aStyleContext,
+                            nsStyleContext* aStyleContext,
                             TextStyle& aTextStyle,
                             nscoord dx, nscoord dy)
 {
@@ -6011,8 +6011,7 @@ nsTextFrame::ComputeWordFragmentDimensions(nsIPresContext* aPresContext,
   if((*aStop) && (wordLen == 0))
     return dimensions; // 0;
 
-  nsCOMPtr<nsIStyleContext> sc;
-  aTextFrame->GetStyleContext(getter_AddRefs(sc));
+  nsStyleContext* sc = aTextFrame->GetStyleContext();
   if (sc) {
     // Measure the piece of text. Note that we have to select the
     // appropriate font into the text first because the rendering
diff --git a/mozilla/layout/html/base/src/nsAreaFrame.cpp b/mozilla/layout/html/base/src/nsAreaFrame.cpp
index bab53c25640..27fd2843e28 100644
--- a/mozilla/layout/html/base/src/nsAreaFrame.cpp
+++ b/mozilla/layout/html/base/src/nsAreaFrame.cpp
@@ -36,7 +36,7 @@
  * ***** END LICENSE BLOCK ***** */
 #include "nsAreaFrame.h"
 #include "nsBlockBandData.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIPresContext.h"
 #include "nsIViewManager.h"
@@ -143,7 +143,7 @@ NS_IMETHODIMP
 nsAreaFrame::Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsBlockFrame::Init(aPresContext,
diff --git a/mozilla/layout/html/base/src/nsAreaFrame.h b/mozilla/layout/html/base/src/nsAreaFrame.h
index 96a4abc9bc0..add72c3cd9a 100644
--- a/mozilla/layout/html/base/src/nsAreaFrame.h
+++ b/mozilla/layout/html/base/src/nsAreaFrame.h
@@ -62,7 +62,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
diff --git a/mozilla/layout/html/base/src/nsBlockFrame.cpp b/mozilla/layout/html/base/src/nsBlockFrame.cpp
index 370d72c812e..508cd9989c8 100644
--- a/mozilla/layout/html/base/src/nsBlockFrame.cpp
+++ b/mozilla/layout/html/base/src/nsBlockFrame.cpp
@@ -53,7 +53,7 @@
 #include "nsIPresContext.h"
 #include "nsIPresShell.h"
 #include "nsReflowPath.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIView.h"
 #include "nsIFontMetrics.h"
 #include "nsHTMLParts.h"
@@ -75,6 +75,7 @@
 #include "plstr.h"
 #include "nsGUIEvent.h"
 #include "nsLayoutErrors.h"
+#include "nsAutoPtr.h"
 
 #ifdef IBMBIDI
 #include "nsBidiPresUtils.h"
@@ -198,13 +199,11 @@ DumpStyleGeneaology(nsIFrame* aFrame, const char* gap)
   fputs(gap, stdout);
   nsFrame::ListTag(stdout, aFrame);
   printf(": ");
-  nsIStyleContext* sc;
-  aFrame->GetStyleContext(&sc);
+  nsStyleContext* sc = aFrame->GetStyleContext();
   while (nsnull != sc) {
-    nsIStyleContext* psc;
+    nsStyleContext* psc;
     printf("%p ", sc);
     psc = sc->GetParent();
-    NS_RELEASE(sc);
     sc = psc;
   }
   printf("\n");
@@ -5554,7 +5553,7 @@ nsBlockFrame::IsVisibleForPainting(nsIPresContext *     aPresContext,
   // first check to see if we are visible
   if (aCheckVis) {
     const nsStyleVisibility* vis = 
-      (const nsStyleVisibility*)((nsIStyleContext*)mStyleContext)->GetStyleData(eStyleStruct_Visibility);
+      (const nsStyleVisibility*)mStyleContext->GetStyleData(eStyleStruct_Visibility);
     if (!vis->IsVisible()) {
       *aIsVisible = PR_FALSE;
       return NS_OK;
@@ -6308,7 +6307,7 @@ NS_IMETHODIMP
 nsBlockFrame::Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        aPrevInFlow)
 {
   if (aPrevInFlow) {
@@ -6323,7 +6322,7 @@ nsBlockFrame::Init(nsIPresContext*  aPresContext,
   return rv;
 }
 
-nsIStyleContext*
+already_AddRefed<nsStyleContext>
 nsBlockFrame::GetFirstLetterStyle(nsIPresContext* aPresContext)
 {
   // This check is here because nsComboboxControlFrame creates
@@ -6336,11 +6335,9 @@ nsBlockFrame::GetFirstLetterStyle(nsIPresContext* aPresContext)
   if (!mContent->IsContentOfType(nsIContent::eELEMENT))
     return nsnull;
 
-  nsIStyleContext* fls;
-  aPresContext->ProbePseudoStyleContextFor(mContent,
-                                           nsCSSPseudoElements::firstLetter,
-                                           mStyleContext, &fls);
-  return fls;
+  return aPresContext->ProbePseudoStyleContextFor(mContent,
+                                                  nsCSSPseudoElements::firstLetter,
+                                                  mStyleContext);
 }
 
 NS_IMETHODIMP
@@ -6360,14 +6357,13 @@ nsBlockFrame::SetInitialChildList(nsIPresContext* aPresContext,
 
     // Lookup up the two pseudo style contexts
     if (nsnull == mPrevInFlow) {
-      nsIStyleContext* firstLetterStyle = GetFirstLetterStyle(aPresContext);
+      nsRefPtr<nsStyleContext> firstLetterStyle = GetFirstLetterStyle(aPresContext);
       if (nsnull != firstLetterStyle) {
         mState |= NS_BLOCK_HAS_FIRST_LETTER_STYLE;
 #ifdef NOISY_FIRST_LETTER
         ListTag(stdout);
         printf(": first-letter style found\n");
 #endif
-        NS_RELEASE(firstLetterStyle);
       }
     }
 
@@ -6398,9 +6394,7 @@ nsBlockFrame::SetInitialChildList(nsIPresContext* aPresContext,
           pseudoElement = nsCSSPseudoElements::mozListNumber;
           break;
       }
-      nsIStyleContext* kidSC;
-      aPresContext->ResolvePseudoStyleContextFor(mContent, pseudoElement,
-                                                 mStyleContext, &kidSC);
+      nsRefPtr<nsStyleContext> kidSC = aPresContext->ResolvePseudoStyleContextFor(mContent, pseudoElement, mStyleContext);
 
       // Create bullet frame
       nsCOMPtr<nsIPresShell> shell;
@@ -6408,11 +6402,9 @@ nsBlockFrame::SetInitialChildList(nsIPresContext* aPresContext,
       mBullet = new (shell.get()) nsBulletFrame;
 
       if (nsnull == mBullet) {
-        NS_RELEASE(kidSC);
         return NS_ERROR_OUT_OF_MEMORY;
       }
       mBullet->Init(aPresContext, mContent, this, kidSC, nsnull);
-      NS_RELEASE(kidSC);
 
       // If the list bullet frame should be positioned inside then add
       // it to the flow now.
diff --git a/mozilla/layout/html/base/src/nsBlockFrame.h b/mozilla/layout/html/base/src/nsBlockFrame.h
index 8ec8a718201..623cff9ad41 100644
--- a/mozilla/layout/html/base/src/nsBlockFrame.h
+++ b/mozilla/layout/html/base/src/nsBlockFrame.h
@@ -99,7 +99,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   NS_IMETHOD SetInitialChildList(nsIPresContext* aPresContext,
                                  nsIAtom*        aListName,
@@ -210,7 +210,7 @@ protected:
   nsBlockFrame();
   virtual ~nsBlockFrame();
 
-  nsIStyleContext* GetFirstLetterStyle(nsIPresContext* aPresContext);
+  already_AddRefed<nsStyleContext> GetFirstLetterStyle(nsIPresContext* aPresContext);
 
   /*
    * Overides member function of nsHTMLContainerFrame. Needed to handle the 
diff --git a/mozilla/layout/html/base/src/nsBlockReflowContext.cpp b/mozilla/layout/html/base/src/nsBlockReflowContext.cpp
index e35bfb713da..a1b6318e83a 100644
--- a/mozilla/layout/html/base/src/nsBlockReflowContext.cpp
+++ b/mozilla/layout/html/base/src/nsBlockReflowContext.cpp
@@ -42,7 +42,7 @@
 #include "nsIFontMetrics.h"
 #include "nsIPresContext.h"
 #include "nsIContent.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsHTMLReflowCommand.h"
 #include "nsHTMLContainerFrame.h"
 #include "nsBlockFrame.h"
@@ -786,8 +786,7 @@ nsStyleUnit
 nsBlockReflowContext::GetRealMarginLeftUnit()
 {
   nsStyleUnit unit = eStyleUnit_Inherit;
-  nsCOMPtr<nsIStyleContext> sc;
-  mFrame->GetStyleContext(getter_AddRefs(sc));
+  nsStyleContext* sc = mFrame->GetStyleContext();
   while (sc && eStyleUnit_Inherit == unit) {
     // Get parent style context
     sc = sc->GetParent();
@@ -807,8 +806,7 @@ nsStyleUnit
 nsBlockReflowContext::GetRealMarginRightUnit()
 {
   nsStyleUnit unit = eStyleUnit_Inherit;
-  nsCOMPtr<nsIStyleContext> sc;
-  mFrame->GetStyleContext(getter_AddRefs(sc));
+  nsStyleContext* sc = mFrame->GetStyleContext();
   while (sc && eStyleUnit_Inherit == unit) {
     // Get parent style context
     sc = sc->GetParent();
diff --git a/mozilla/layout/html/base/src/nsBulletFrame.cpp b/mozilla/layout/html/base/src/nsBulletFrame.cpp
index 2212c45faa6..eed04aea899 100644
--- a/mozilla/layout/html/base/src/nsBulletFrame.cpp
+++ b/mozilla/layout/html/base/src/nsBulletFrame.cpp
@@ -113,7 +113,7 @@ NS_IMETHODIMP
 nsBulletFrame::Init(nsIPresContext*  aPresContext,
                     nsIContent*      aContent,
                     nsIFrame*        aParent,
-                    nsIStyleContext* aContext,
+                    nsStyleContext*  aContext,
                     nsIFrame*        aPrevInFlow)
 {
   nsresult  rv = nsFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/html/base/src/nsBulletFrame.h b/mozilla/layout/html/base/src/nsBulletFrame.h
index db8e0631bc1..25cb6643fe5 100644
--- a/mozilla/layout/html/base/src/nsBulletFrame.h
+++ b/mozilla/layout/html/base/src/nsBulletFrame.h
@@ -38,7 +38,7 @@
 #define nsBulletFrame_h___
 
 #include "nsFrame.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 
 #include "imgIRequest.h"
 #include "imgIDecoderObserver.h"
@@ -57,7 +57,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
   NS_IMETHOD Paint(nsIPresContext*      aCX,
diff --git a/mozilla/layout/html/base/src/nsContainerFrame.cpp b/mozilla/layout/html/base/src/nsContainerFrame.cpp
index 779914bd1fd..d7a65cea61c 100644
--- a/mozilla/layout/html/base/src/nsContainerFrame.cpp
+++ b/mozilla/layout/html/base/src/nsContainerFrame.cpp
@@ -39,7 +39,7 @@
 #include "nsIContent.h"
 #include "nsIPresContext.h"
 #include "nsIRenderingContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsRect.h"
 #include "nsPoint.h"
 #include "nsGUIEvent.h"
@@ -84,7 +84,7 @@ NS_IMETHODIMP
 nsContainerFrame::Init(nsIPresContext*  aPresContext,
                        nsIContent*      aContent,
                        nsIFrame*        aParent,
-                       nsIStyleContext* aContext,
+                       nsStyleContext*  aContext,
                        nsIFrame*        aPrevInFlow)
 {
   nsresult rv;
@@ -514,7 +514,7 @@ NonZeroStyleCoord(const nsStyleCoord& aCoord) {
 }
 
 static PRBool
-HasNonZeroBorderRadius(nsIStyleContext* aStyleContext) {
+HasNonZeroBorderRadius(nsStyleContext* aStyleContext) {
   const nsStyleBorder* border;
   ::GetStyleData(aStyleContext, &border);
 
@@ -534,7 +534,7 @@ HasNonZeroBorderRadius(nsIStyleContext* aStyleContext) {
 static void
 SyncFrameViewGeometryDependentProperties(nsIPresContext*  aPresContext,
                                          nsIFrame*        aFrame,
-                                         nsIStyleContext* aStyleContext,
+                                         nsStyleContext*  aStyleContext,
                                          nsIView*         aView,
                                          PRUint32         aFlags)
 {
@@ -735,8 +735,7 @@ nsContainerFrame::SyncFrameViewAfterReflow(nsIPresContext* aPresContext,
     // detect whether it has or not. Likewise, whether the view size
     // has changed or not, we may need to change the transparency
     // state even if there is no clip.
-    nsCOMPtr<nsIStyleContext> savedStyleContext;
-    aFrame->GetStyleContext(getter_AddRefs(savedStyleContext));
+    nsStyleContext* savedStyleContext = aFrame->GetStyleContext();
     SyncFrameViewGeometryDependentProperties(aPresContext, aFrame, savedStyleContext, aView, aFlags);
   }
 }
@@ -744,7 +743,7 @@ nsContainerFrame::SyncFrameViewAfterReflow(nsIPresContext* aPresContext,
 void
 nsContainerFrame::SyncFrameViewAfterSizeChange(nsIPresContext*  aPresContext,
                                                nsIFrame*        aFrame,
-                                               nsIStyleContext* aStyleContext,
+                                               nsStyleContext*  aStyleContext,
                                                nsIView*         aView,
                                                PRUint32         aFlags)
 {
@@ -752,10 +751,8 @@ nsContainerFrame::SyncFrameViewAfterSizeChange(nsIPresContext*  aPresContext,
     return;
   }
   
-  nsCOMPtr<nsIStyleContext> savedStyleContext;
   if (nsnull == aStyleContext) {
-    aFrame->GetStyleContext(getter_AddRefs(savedStyleContext));
-    aStyleContext = savedStyleContext;
+    aStyleContext = aFrame->GetStyleContext();
   }
 
   SyncFrameViewGeometryDependentProperties(aPresContext, aFrame, aStyleContext, aView, aFlags);
@@ -764,7 +761,7 @@ nsContainerFrame::SyncFrameViewAfterSizeChange(nsIPresContext*  aPresContext,
 void
 nsContainerFrame::SyncFrameViewProperties(nsIPresContext*  aPresContext,
                                           nsIFrame*        aFrame,
-                                          nsIStyleContext* aStyleContext,
+                                          nsStyleContext*  aStyleContext,
                                           nsIView*         aView,
                                           PRUint32         aFlags)
 {
@@ -775,10 +772,8 @@ nsContainerFrame::SyncFrameViewProperties(nsIPresContext*  aPresContext,
   nsCOMPtr<nsIViewManager> vm;
   aView->GetViewManager(*getter_AddRefs(vm));
 
-  nsCOMPtr<nsIStyleContext> savedStyleContext;
   if (nsnull == aStyleContext) {
-    aFrame->GetStyleContext(getter_AddRefs(savedStyleContext));
-    aStyleContext = savedStyleContext;
+    aStyleContext = aFrame->GetStyleContext();
   }
     
   const nsStyleVisibility* vis;
@@ -859,7 +854,7 @@ nsContainerFrame::SyncFrameViewProperties(nsIPresContext*  aPresContext,
 PRBool
 nsContainerFrame::FrameNeedsView(nsIPresContext* aPresContext,
                                  nsIFrame* aFrame,
-                                 nsIStyleContext* aStyleContext)
+                                 nsStyleContext* aStyleContext)
 {
   const nsStyleVisibility* vis;
   ::GetStyleData(aStyleContext, &vis);
@@ -887,8 +882,7 @@ nsContainerFrame::FrameNeedsView(nsIPresContext* aPresContext,
     return PR_TRUE;
   } 
 
-  nsCOMPtr<nsIAtom>  pseudoTag;
-  aStyleContext->GetPseudoType(*getter_AddRefs(pseudoTag));
+  nsCOMPtr<nsIAtom>  pseudoTag = aStyleContext->GetPseudoType();
   if (pseudoTag == nsCSSAnonBoxes::scrolledContent) {
     return PR_TRUE;
   }
diff --git a/mozilla/layout/html/base/src/nsContainerFrame.h b/mozilla/layout/html/base/src/nsContainerFrame.h
index 444d9efcd2d..8b859a1701b 100644
--- a/mozilla/layout/html/base/src/nsContainerFrame.h
+++ b/mozilla/layout/html/base/src/nsContainerFrame.h
@@ -57,7 +57,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   NS_IMETHOD SetInitialChildList(nsIPresContext* aPresContext,
                                  nsIAtom*        aListName,
@@ -118,7 +118,7 @@ public:
   // @param aStyleContext can be null, in which case the frame's style context is used
   static void SyncFrameViewAfterSizeChange(nsIPresContext*  aPresContext,
                                            nsIFrame*        aFrame,
-                                           nsIStyleContext* aStyleContext,
+                                           nsStyleContext*  aStyleContext,
                                            nsIView*         aView,
                                            PRUint32         aFlags = 0);
   
@@ -132,13 +132,13 @@ public:
   // @param aStyleContext can be null, in which case the frame's style context is used
   static void SyncFrameViewProperties(nsIPresContext*  aPresContext,
                                       nsIFrame*        aFrame,
-                                      nsIStyleContext* aStyleContext,
+                                      nsStyleContext*  aStyleContext,
                                       nsIView*         aView,
                                       PRUint32         aFlags = 0);
 
   // Returns PR_TRUE if the frame requires a view
   static PRBool FrameNeedsView(nsIPresContext* aPresContext,
-                               nsIFrame* aFrame, nsIStyleContext* aStyleContext);
+                               nsIFrame* aFrame, nsStyleContext* aStyleContext);
   
   /**
    * Invokes the WillReflow() function, positions the frame and its view (if
diff --git a/mozilla/layout/html/base/src/nsFirstLetterFrame.cpp b/mozilla/layout/html/base/src/nsFirstLetterFrame.cpp
index 970f1acda2a..b8b5ef0f4ae 100644
--- a/mozilla/layout/html/base/src/nsFirstLetterFrame.cpp
+++ b/mozilla/layout/html/base/src/nsFirstLetterFrame.cpp
@@ -37,11 +37,12 @@
 #include "nsCOMPtr.h"
 #include "nsHTMLContainerFrame.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIContent.h"
 #include "nsLineLayout.h"
 #include "nsHTMLAtoms.h"
 #include "nsLayoutAtoms.h"
+#include "nsAutoPtr.h"
 
 #define nsFirstLetterFrameSuper nsHTMLContainerFrame
 
@@ -52,7 +53,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   NS_IMETHOD SetInitialChildList(nsIPresContext* aPresContext,
                                  nsIAtom*        aListName,
@@ -128,23 +129,18 @@ NS_IMETHODIMP
 nsFirstLetterFrame::Init(nsIPresContext*  aPresContext,
                          nsIContent*      aContent,
                          nsIFrame*        aParent,
-                         nsIStyleContext* aContext,
+                         nsStyleContext*  aContext,
                          nsIFrame*        aPrevInFlow)
 {
   nsresult rv;
-  nsCOMPtr<nsIStyleContext> newSC;
+  nsRefPtr<nsStyleContext> newSC;
   if (aPrevInFlow) {
     // Get proper style context for ourselves.  We're creating the frame
     // that represents everything *except* the first letter, so just create
     // a style context like we would for a text node.
-    nsCOMPtr<nsIStyleContext> parentStyleContext = aContext->GetParent();
+    nsStyleContext* parentStyleContext = aContext->GetParent();
     if (parentStyleContext) {
-      rv = aPresContext->ResolveStyleContextForNonElement(
-                                                   parentStyleContext,
-                                                   getter_AddRefs(newSC));
-      if (NS_FAILED(rv))
-        return rv;
-
+      newSC = aPresContext->ResolveStyleContextForNonElement(parentStyleContext);
       if (newSC)
         aContext = newSC;
     }
@@ -350,14 +346,13 @@ nsFirstLetterFrame::DrainOverflowFrames(nsIPresContext* aPresContext)
   // are reflowed)
   nsIFrame* kid = mFrames.FirstChild();
   if (kid) {
-    nsCOMPtr<nsIStyleContext> sc;
+    nsRefPtr<nsStyleContext> sc;
     nsCOMPtr<nsIContent> kidContent;
     kid->GetContent(getter_AddRefs(kidContent));
     if (kidContent) {
       NS_ASSERTION(kidContent->IsContentOfType(nsIContent::eTEXT),
                    "should contain only text nodes");
-      aPresContext->ResolveStyleContextForNonElement(mStyleContext,
-                                                     getter_AddRefs(sc));
+      sc = aPresContext->ResolveStyleContextForNonElement(mStyleContext);
       if (sc) {
         kid->SetStyleContext(aPresContext, sc);
       }
diff --git a/mozilla/layout/html/base/src/nsFrame.cpp b/mozilla/layout/html/base/src/nsFrame.cpp
index 65cc21badaf..5fe6b2a23cd 100644
--- a/mozilla/layout/html/base/src/nsFrame.cpp
+++ b/mozilla/layout/html/base/src/nsFrame.cpp
@@ -44,7 +44,7 @@
 #include "nsIAtom.h"
 #include "nsIArena.h"
 #include "nsString.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIView.h"
 #include "nsIViewManager.h"
 #include "nsIPresContext.h"
@@ -397,7 +397,7 @@ nsresult NS_NewSelectionImageService(nsISelectionImageService** aResult)
 //end selection service
 
 // a handy utility to set font
-void SetFontFromStyle(nsIRenderingContext* aRC, nsIStyleContext* aSC) 
+void SetFontFromStyle(nsIRenderingContext* aRC, nsStyleContext* aSC) 
 {
   const nsStyleFont *font = (const nsStyleFont*)
     aSC->GetStyleData(eStyleStruct_Font);
@@ -479,7 +479,8 @@ nsFrame::~nsFrame()
   MOZ_COUNT_DTOR(nsFrame);
 
   NS_IF_RELEASE(mContent);
-  NS_IF_RELEASE(mStyleContext);
+  if (mStyleContext)
+    mStyleContext->Release();
 }
 
 /////////////////////////////////////////////////////////////////////////////
@@ -525,7 +526,7 @@ NS_IMETHODIMP
 nsFrame::Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow)
 {
   mContent = aContent;
@@ -554,7 +555,8 @@ nsFrame::Init(nsIPresContext*  aPresContext,
     mState |= state & (NS_FRAME_INDEPENDENT_SELECTION |
                        NS_FRAME_GENERATED_CONTENT);
   }
-  return SetStyleContext(aPresContext, aContext);
+  SetStyleContext(aPresContext, aContext);
+  return NS_OK;
 }
 
 NS_IMETHODIMP nsFrame::SetInitialChildList(nsIPresContext* aPresContext,
@@ -688,25 +690,18 @@ NS_IMETHODIMP  nsFrame::CalcBorderPadding(nsMargin& aBorderPadding) const {
   return NS_ERROR_FAILURE;
 }
 
-NS_IMETHODIMP
-nsFrame::GetAdditionalStyleContext(PRInt32 aIndex, 
-                                   nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
 {
   NS_PRECONDITION(aIndex >= 0, "invalid index number");
-  NS_ASSERTION(aStyleContext, "null ptr");
-  if (! aStyleContext) {
-    return NS_ERROR_NULL_POINTER;
-  }
-  *aStyleContext = nsnull;
-  return NS_ERROR_INVALID_ARG;
+  return nsnull;
 }
 
-NS_IMETHODIMP
+void
 nsFrame::SetAdditionalStyleContext(PRInt32 aIndex, 
-                                   nsIStyleContext* aStyleContext)
+                                   nsStyleContext* aStyleContext)
 {
   NS_PRECONDITION(aIndex >= 0, "invalid index number");
-  return ((aIndex < 0) ? NS_ERROR_INVALID_ARG : NS_OK);
 }
 
 // Child frame enumeration
@@ -2103,7 +2098,7 @@ nsFrame::GetFrameForPoint(nsIPresContext* aPresContext,
   if ((aWhichLayer == NS_FRAME_PAINT_LAYER_FOREGROUND) &&
       (mRect.Contains(aPoint))) {
     const nsStyleVisibility* vis = 
-      (const nsStyleVisibility*)((nsIStyleContext*)mStyleContext)->GetStyleData(eStyleStruct_Visibility);
+      (const nsStyleVisibility*)((nsStyleContext*)mStyleContext)->GetStyleData(eStyleStruct_Visibility);
     if (vis->IsVisible()) {
       *aFrame = this;
       return NS_OK;
@@ -2898,7 +2893,7 @@ nsFrame::IsVisibleForPainting(nsIPresContext *     aPresContext,
   // first check to see if we are visible
   if (aCheckVis) {
     const nsStyleVisibility* vis = 
-      (const nsStyleVisibility*)((nsIStyleContext*)mStyleContext)->GetStyleData(eStyleStruct_Visibility);
+      (const nsStyleVisibility*)((nsStyleContext*)mStyleContext)->GetStyleData(eStyleStruct_Visibility);
     if (!vis->IsVisible()) {
       *aIsVisible = PR_FALSE;
       return NS_OK;
diff --git a/mozilla/layout/html/base/src/nsFrame.h b/mozilla/layout/html/base/src/nsFrame.h
index 69579b87143..6973021546b 100644
--- a/mozilla/layout/html/base/src/nsFrame.h
+++ b/mozilla/layout/html/base/src/nsFrame.h
@@ -112,7 +112,7 @@
 #endif
 
 // handy utilities
-extern void SetFontFromStyle(nsIRenderingContext* aRC, nsIStyleContext* aSC);
+extern void SetFontFromStyle(nsIRenderingContext* aRC, nsStyleContext* aSC);
 
 //----------------------------------------------------------------------
 
@@ -158,7 +158,7 @@ public:
   NS_IMETHOD  Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        asPrevInFlow);
   NS_IMETHOD  SetInitialChildList(nsIPresContext* aPresContext,
                                   nsIAtom*        aListName,
@@ -183,10 +183,9 @@ public:
                            nsIFrame*       aNewFrame);
   NS_IMETHOD  Destroy(nsIPresContext* aPresContext);
   NS_IMETHOD  CalcBorderPadding(nsMargin& aBorderPadding) const;
-  NS_IMETHOD  GetAdditionalStyleContext(PRInt32 aIndex, 
-                                        nsIStyleContext** aStyleContext) const;
-  NS_IMETHOD  SetAdditionalStyleContext(PRInt32 aIndex, 
-                                        nsIStyleContext* aStyleContext);
+  virtual nsStyleContext* GetAdditionalStyleContext(PRInt32 aIndex) const;
+  virtual void SetAdditionalStyleContext(PRInt32 aIndex,
+                                         nsStyleContext* aStyleContext);
   NS_IMETHOD  GetAdditionalChildListName(PRInt32 aIndex, nsIAtom** aListName) const;
   NS_IMETHOD  FirstChild(nsIPresContext* aPresContext,
                          nsIAtom*        aListName,
diff --git a/mozilla/layout/html/base/src/nsFrameManager.cpp b/mozilla/layout/html/base/src/nsFrameManager.cpp
index 7975898b4f6..10a01caf312 100644
--- a/mozilla/layout/html/base/src/nsFrameManager.cpp
+++ b/mozilla/layout/html/base/src/nsFrameManager.cpp
@@ -34,7 +34,7 @@
 #include "nsIPresContext.h"
 #include "nsIPresShell.h"
 #include "nsIStyleSet.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleChangeList.h"
 #include "nsIEventQueueService.h"
 #include "nsIServiceManager.h"
@@ -77,6 +77,7 @@
 #include "nsDummyLayoutRequest.h"
 #include "nsLayoutErrors.h"
 #include "nsLayoutUtils.h"
+#include "nsAutoPtr.h"
 
   #ifdef DEBUG
     //#define NOISY_DEBUG
@@ -199,7 +200,7 @@ MOZ_DECL_CTOR_COUNTER(UndisplayedNode)
 
 class UndisplayedNode {
 public:
-  UndisplayedNode(nsIContent* aContent, nsIStyleContext* aStyle)
+  UndisplayedNode(nsIContent* aContent, nsStyleContext* aStyle)
     : mContent(aContent),
       mStyle(aStyle),
       mNext(nsnull)
@@ -214,7 +215,7 @@ public:
   }
 
   nsCOMPtr<nsIContent>      mContent;
-  nsCOMPtr<nsIStyleContext> mStyle;
+  nsRefPtr<nsStyleContext>  mStyle;
   UndisplayedNode*          mNext;
 };
 
@@ -225,7 +226,7 @@ public:
 
   UndisplayedNode* GetFirstNode(nsIContent* aParentContent);
 
-  nsresult AddNodeFor(nsIContent* aParentContent, nsIContent* aChild, nsIStyleContext* aStyle);
+  nsresult AddNodeFor(nsIContent* aParentContent, nsIContent* aChild, nsStyleContext* aStyle);
 
   nsresult RemoveNodeFor(nsIContent* aParentContent, UndisplayedNode* aNode);
   nsresult RemoveNodesFor(nsIContent* aParentContent);
@@ -300,8 +301,8 @@ public:
   NS_IMETHOD ClearPlaceholderFrameMap();
 
   // Undisplayed content functions
-  NS_IMETHOD GetUndisplayedContent(nsIContent* aContent, nsIStyleContext** aStyleContext);
-  NS_IMETHOD SetUndisplayedContent(nsIContent* aContent, nsIStyleContext* aStyleContext);
+  virtual nsStyleContext* GetUndisplayedContent(nsIContent* aContent);
+  virtual void SetUndisplayedContent(nsIContent* aContent, nsStyleContext* aStyleContext);
   NS_IMETHOD ClearUndisplayedContentIn(nsIContent* aContent, nsIContent* aParentContent);
   NS_IMETHOD ClearAllUndisplayedContentIn(nsIContent* aParentContent);
   NS_IMETHOD ClearUndisplayedContentMap();
@@ -337,7 +338,7 @@ public:
 
   NS_IMETHOD ReParentStyleContext(nsIPresContext* aPresContext,
                                   nsIFrame* aFrame, 
-                                  nsIStyleContext* aNewParentContext);
+                                  nsStyleContext* aNewParentContext);
   NS_IMETHOD ComputeStyleChangeFor(nsIPresContext* aPresContext,
                                    nsIFrame* aFrame, 
                                    PRInt32 aAttrNameSpaceID,
@@ -834,36 +835,32 @@ FrameManager::ClearPlaceholderFrameMap()
 
 //----------------------------------------------------------------------
 
-NS_IMETHODIMP
-FrameManager::GetUndisplayedContent(nsIContent* aContent, nsIStyleContext** aResult)
+nsStyleContext*
+FrameManager::GetUndisplayedContent(nsIContent* aContent)
 {
-  NS_ENSURE_ARG_POINTER(aContent);
-  *aResult = nsnull;  // initialize out param
-
-  if (!mUndisplayedMap)
-    return NS_OK;
+  if (!aContent || !mUndisplayedMap)
+    return nsnull;
 
   nsCOMPtr<nsIContent> parent;
   aContent->GetParent(*getter_AddRefs(parent));
   if (!parent)
-    return NS_OK;
+    return nsnull;
 
   for (UndisplayedNode* node = mUndisplayedMap->GetFirstNode(parent);
          node; node = node->mNext) {
-    if (node->mContent == aContent) {
-      *aResult = node->mStyle;
-      NS_ADDREF(*aResult);
-      return NS_OK;
-    }
+    if (node->mContent == aContent)
+      return node->mStyle;
   }
-  return NS_OK;
+
+  return nsnull;
 }
   
-NS_IMETHODIMP
+void
 FrameManager::SetUndisplayedContent(nsIContent* aContent, 
-                                    nsIStyleContext* aStyleContext)
+                                    nsStyleContext* aStyleContext)
 {
-  NS_ENSURE_TRUE(mPresShell, NS_ERROR_NOT_AVAILABLE);
+  if (!mPresShell)
+    return;
   
 #ifdef DEBUG_UNDISPLAYED_MAP
    static int i = 0;
@@ -874,17 +871,14 @@ FrameManager::SetUndisplayedContent(nsIContent* aContent,
     mUndisplayedMap = new UndisplayedMap;
   }
   if (mUndisplayedMap) {
-    nsresult result = NS_OK;
     nsIContent* parent = nsnull;
     aContent->GetParent(parent);
     NS_ASSERTION(parent, "undisplayed content must have a parent");
     if (parent) {
-      result = mUndisplayedMap->AddNodeFor(parent, aContent, aStyleContext);
+      mUndisplayedMap->AddNodeFor(parent, aContent, aStyleContext);
       NS_RELEASE(parent);
     }
-    return result;
   }
-  return NS_ERROR_OUT_OF_MEMORY;
 }
 
 NS_IMETHODIMP
@@ -908,8 +902,7 @@ FrameManager::ClearUndisplayedContentIn(nsIContent* aContent, nsIContent* aParen
 #endif
 #ifdef DEBUG
         // make sure that there are no more entries for the same content
-        nsIStyleContext *context = nsnull;
-        GetUndisplayedContent(aContent, &context);
+        nsStyleContext *context = GetUndisplayedContent(aContent);
         NS_ASSERTION(context == nsnull, "Found more undisplayed content data after removal");
 #endif
         return rv;
@@ -1306,7 +1299,7 @@ FrameManager::CantRenderReplacedElement(nsIPresContext* aPresContext,
 
 #ifdef NS_DEBUG
 static void
-DumpContext(nsIFrame* aFrame, nsIStyleContext* aContext)
+DumpContext(nsIFrame* aFrame, nsStyleContext* aContext)
 {
   if (aFrame) {
     fputs("frame: ", stdout);
@@ -1322,14 +1315,12 @@ DumpContext(nsIFrame* aFrame, nsIStyleContext* aContext)
   if (aContext) {
     fprintf(stdout, " style: %p ", NS_STATIC_CAST(void*, aContext));
 
-    nsIAtom* pseudoTag;
-    aContext->GetPseudoType(pseudoTag);
+    nsCOMPtr<nsIAtom> pseudoTag = aContext->GetPseudoType();
     if (pseudoTag) {
       nsAutoString  buffer;
       pseudoTag->ToString(buffer);
       fputs(NS_LossyConvertUCS2toASCII(buffer).get(), stdout);
       fputs(" ", stdout);
-      NS_RELEASE(pseudoTag);
     }
 
 /* XXXdwh fix debugging here.  Need to add a List method to nsRuleNode
@@ -1356,11 +1347,11 @@ DumpContext(nsIFrame* aFrame, nsIStyleContext* aContext)
 }
 
 static void
-VerifySameTree(nsIStyleContext* aContext1, nsIStyleContext* aContext2)
+VerifySameTree(nsStyleContext* aContext1, nsStyleContext* aContext2)
 {
-  nsCOMPtr<nsIStyleContext> top1 = aContext1;
-  nsCOMPtr<nsIStyleContext> top2 = aContext2;
-  nsCOMPtr<nsIStyleContext> parent;
+  nsStyleContext* top1 = aContext1;
+  nsStyleContext* top2 = aContext2;
+  nsStyleContext* parent;
   for (;;) {
     parent = top1->GetParent();
     if (!parent)
@@ -1379,14 +1370,11 @@ VerifySameTree(nsIStyleContext* aContext1, nsIStyleContext* aContext2)
 
 static void
 VerifyContextParent(nsIPresContext* aPresContext, nsIFrame* aFrame, 
-                    nsIStyleContext* aContext, nsIStyleContext* aParentContext)
+                    nsStyleContext* aContext, nsStyleContext* aParentContext)
 {
   // get the contexts not provided
   if (!aContext) {
-    aFrame->GetStyleContext(&aContext);
-  } else {
-    // addref here so we can release at end
-    NS_ADDREF(aContext);
+    aContext = aFrame->GetStyleContext();
   }
 
   if (!aParentContext) {
@@ -1400,15 +1388,12 @@ VerifyContextParent(nsIPresContext* aPresContext, nsIFrame* aFrame,
     aFrame->GetParentStyleContextFrame(aPresContext,
                                        &providerFrame, &providerIsChild);
     if (providerFrame)
-      providerFrame->GetStyleContext(&aParentContext);
+      aParentContext = providerFrame->GetStyleContext();
     // aParentContext could still be null
-  } else {
-    // addref the parent context so we can release it at end
-    NS_ADDREF(aParentContext);
   }
 
   NS_ASSERTION(aContext, "Failure to get required contexts");
-  nsCOMPtr<nsIStyleContext> actualParentContext = aContext->GetParent();
+  nsStyleContext* actualParentContext = aContext->GetParent();
 
   if (aParentContext) {
     if (aParentContext != actualParentContext) {
@@ -1434,17 +1419,12 @@ VerifyContextParent(nsIPresContext* aPresContext, nsIFrame* aFrame,
       fputs("Should be null\n\n", stdout);
     }
   }
-
-  NS_IF_RELEASE(aParentContext);
-  NS_IF_RELEASE(aContext);
 }
 
 static void
-VerifyStyleTree(nsIPresContext* aPresContext, nsIFrame* aFrame, nsIStyleContext* aParentContext)
+VerifyStyleTree(nsIPresContext* aPresContext, nsIFrame* aFrame, nsStyleContext* aParentContext)
 {
-  nsIStyleContext*  context;
-  aFrame->GetStyleContext(&context);
-
+  nsStyleContext*  context = aFrame->GetStyleContext();
   VerifyContextParent(aPresContext, aFrame, context, nsnull);
 
   PRInt32 listIndex = 0;
@@ -1488,18 +1468,15 @@ VerifyStyleTree(nsIPresContext* aPresContext, nsIFrame* aFrame, nsIStyleContext*
   
   // do additional contexts 
   PRInt32 contextIndex = -1;
-  while (1 == 1) {
-    nsIStyleContext* extraContext = nsnull;
-    aFrame->GetAdditionalStyleContext(++contextIndex, &extraContext);
+  while (1) {
+    nsStyleContext* extraContext = aFrame->GetAdditionalStyleContext(++contextIndex);
     if (extraContext) {
       VerifyContextParent(aPresContext, aFrame, extraContext, context);
-      NS_RELEASE(extraContext);
     }
     else {
       break;
     }
   }
-  NS_RELEASE(context);
 }
 
 NS_IMETHODIMP
@@ -1507,9 +1484,8 @@ FrameManager::DebugVerifyStyleTree(nsIPresContext* aPresContext, nsIFrame* aFram
 {
   NS_ENSURE_TRUE(mPresShell, NS_ERROR_NOT_AVAILABLE);
   if (aFrame) {
-    nsCOMPtr<nsIStyleContext> context;
-    aFrame->GetStyleContext(getter_AddRefs(context));
-    nsCOMPtr<nsIStyleContext> parentContext = context->GetParent();
+    nsStyleContext* context = aFrame->GetStyleContext();
+    nsStyleContext* parentContext = context->GetParent();
     VerifyStyleTree(aPresContext, aFrame, parentContext);
   }
   return NS_OK;
@@ -1520,7 +1496,7 @@ FrameManager::DebugVerifyStyleTree(nsIPresContext* aPresContext, nsIFrame* aFram
 NS_IMETHODIMP
 FrameManager::ReParentStyleContext(nsIPresContext* aPresContext,
                                    nsIFrame* aFrame, 
-                                   nsIStyleContext* aNewParentContext)
+                                   nsStyleContext* aNewParentContext)
 {
   NS_ENSURE_TRUE(mPresShell, NS_ERROR_NOT_AVAILABLE);
   nsresult result = NS_ERROR_NULL_POINTER;
@@ -1529,15 +1505,13 @@ FrameManager::ReParentStyleContext(nsIPresContext* aPresContext,
     DebugVerifyStyleTree(aPresContext, aFrame);
 #endif
 
-    nsIStyleContext* oldContext = nsnull;
-    aFrame->GetStyleContext(&oldContext);
-
+    nsStyleContext* oldContext = aFrame->GetStyleContext();
     if (oldContext) {
-      nsIStyleContext* newContext = nsnull;
-      result = mStyleSet->ReParentStyleContext(aPresContext, 
-                                               oldContext, aNewParentContext,
-                                               &newContext);
-      if (NS_SUCCEEDED(result) && newContext) {
+      nsRefPtr<nsStyleContext> newContext;
+      result = NS_OK;
+      newContext = mStyleSet->ReParentStyleContext(aPresContext, oldContext,
+                                                   aNewParentContext);
+      if (newContext) {
         if (newContext != oldContext) {
           PRInt32 listIndex = 0;
           nsIAtom* childList = nsnull;
@@ -1561,10 +1535,8 @@ FrameManager::ReParentStyleContext(nsIPresContext* aPresContext,
                   result = ReParentStyleContext(aPresContext, outOfFlowFrame, newContext);
 
                   // reparent placeholder's context under out of flow frame
-                  nsIStyleContext*  outOfFlowContext;
-                  outOfFlowFrame->GetStyleContext(&outOfFlowContext);
+                  nsStyleContext* outOfFlowContext = outOfFlowFrame->GetStyleContext();
                   ReParentStyleContext(aPresContext, child, outOfFlowContext);
-                  NS_RELEASE(outOfFlowContext);
                 }
                 else { // regular frame
                   result = ReParentStyleContext(aPresContext, child, newContext);
@@ -1583,20 +1555,15 @@ FrameManager::ReParentStyleContext(nsIPresContext* aPresContext,
 
           // do additional contexts 
           PRInt32 contextIndex = -1;
-          while (1 == 1) {
-            nsIStyleContext* oldExtraContext = nsnull;
-            result = aFrame->GetAdditionalStyleContext(++contextIndex, &oldExtraContext);
-            if (NS_SUCCEEDED(result)) {
-              if (oldExtraContext) {
-                nsIStyleContext* newExtraContext = nsnull;
-                result = mStyleSet->ReParentStyleContext(aPresContext,
-                                                         oldExtraContext, newContext,
-                                                         &newExtraContext);
-                if (NS_SUCCEEDED(result) && newExtraContext) {
-                  aFrame->SetAdditionalStyleContext(contextIndex, newExtraContext);
-                  NS_RELEASE(newExtraContext);
-                }
-                NS_RELEASE(oldExtraContext);
+          while (1) {
+            nsStyleContext* oldExtraContext = aFrame->GetAdditionalStyleContext(++contextIndex);
+            if (oldExtraContext) {
+              nsRefPtr<nsStyleContext> newExtraContext;
+              newExtraContext = mStyleSet->ReParentStyleContext(aPresContext,
+                                                                oldExtraContext,
+                                                                newContext);
+              if (newExtraContext) {
+                aFrame->SetAdditionalStyleContext(contextIndex, newExtraContext);
               }
             }
             else {
@@ -1608,16 +1575,14 @@ FrameManager::ReParentStyleContext(nsIPresContext* aPresContext,
           VerifyStyleTree(aPresContext, aFrame, aNewParentContext);
 #endif
         }
-        NS_RELEASE(newContext);
       }
-      NS_RELEASE(oldContext);
     }
   }
   return result;
 }
 
 static PRBool
-HasAttributeContent(nsIStyleContext* aStyleContext, 
+HasAttributeContent(nsStyleContext* aStyleContext, 
                     PRInt32 aNameSpaceID,
                     nsIAtom* aAttribute)
 {
@@ -1659,12 +1624,12 @@ HasAttributeContent(nsIStyleContext* aStyleContext,
 }
 
 static nsChangeHint
-CaptureChange(nsIStyleContext* aOldContext, nsIStyleContext* aNewContext,
+CaptureChange(nsStyleContext* aOldContext, nsStyleContext* aNewContext,
               nsIFrame* aFrame, nsIContent* aContent,
               nsStyleChangeList& aChangeList, nsChangeHint aMinChange)
 {
   nsChangeHint ourChange = NS_STYLE_HINT_NONE;
-  aOldContext->CalcStyleDifference(aNewContext, ourChange);
+  ourChange = aOldContext->CalcStyleDifference(aNewContext);
   if (NS_UpdateHint(aMinChange, ourChange)) {
     aChangeList.AppendChange(aFrame, aContent, ourChange);
   }
@@ -1685,11 +1650,16 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
   // duplication.  (Or should we just let |GetContext| handle that?)
   // Getting the hint would be nice too, but that's harder.
 
-  nsIStyleContext* oldContext = nsnull; 
-  nsresult result = aFrame->GetStyleContext(&oldContext);
-  if (NS_SUCCEEDED(result) && oldContext) {
-    nsIAtom* pseudoTag = nsnull;
-    oldContext->GetPseudoType(pseudoTag);
+  // XXXbryner we may be able to avoid some of the refcounting goop here.
+  // We do need a reference to oldContext for the lifetime of this function, and it's possible
+  // that the frame has the last reference to it, so AddRef it here.
+
+  nsStyleContext* oldContext = aFrame->GetStyleContext();
+  nsresult result = NS_OK;
+
+  if (oldContext) {
+    oldContext->AddRef();
+    nsCOMPtr<nsIAtom> pseudoTag = oldContext->GetPseudoType();
     nsIContent* localContent = nsnull;
     nsIContent* content = nsnull;
     result = aFrame->GetContent(&localContent);
@@ -1707,7 +1677,7 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
       }
     }
 
-    nsCOMPtr<nsIStyleContext> parentContext; 
+    nsStyleContext* parentContext;
     nsIFrame* resolvedChild = nsnull;
     // Get the frame providing the parent style context.  If it is a
     // child, then resolve the provider first.
@@ -1717,7 +1687,9 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
                                        &providerFrame, &providerIsChild); 
     if (!providerIsChild) {
       if (providerFrame)
-        providerFrame->GetStyleContext(getter_AddRefs(parentContext));  
+        parentContext = providerFrame->GetStyleContext();
+      else
+        parentContext = nsnull;
     }
     else {
       // resolve the provider here (before aFrame below)
@@ -1726,19 +1698,18 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
                             aMinChange, aResultChange);
       // The provider's new context becomes the parent context of
       // aFrame's context.
-      providerFrame->GetStyleContext(getter_AddRefs(parentContext)); 
+      parentContext = providerFrame->GetStyleContext();
       // Set |resolvedChild| so we don't bother resolving the
       // provider again.
       resolvedChild = providerFrame;
     }
     
     // do primary context
-    nsIStyleContext* newContext = nsnull;
+    nsStyleContext* newContext = nsnull;
     if (pseudoTag == nsCSSAnonBoxes::mozNonElement) {
       NS_ASSERTION(localContent,
                    "non pseudo-element frame without content node");
-      aPresContext->ResolveStyleContextForNonElement(parentContext,
-                                                     &newContext);
+      newContext = aPresContext->ResolveStyleContextForNonElement(parentContext).get();
     }
     else if (pseudoTag) {
       nsIContent* pseudoContent =
@@ -1746,9 +1717,9 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
       if (pseudoTag == nsCSSPseudoElements::before ||
           pseudoTag == nsCSSPseudoElements::after) {
         // XXX what other pseudos do we need to treat like this?
-        aPresContext->ProbePseudoStyleContextFor(pseudoContent, pseudoTag,
-                                                 parentContext, 
-                                                 &newContext);
+        newContext = aPresContext->ProbePseudoStyleContextFor(pseudoContent,
+                                                              pseudoTag,
+                                                              parentContext).get();
         if (!newContext) {
           // This pseudo should no longer exist; gotta reframe
           NS_UpdateHint(aMinChange, nsChangeHint_ReconstructFrame);
@@ -1756,20 +1727,18 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
                                    nsChangeHint_ReconstructFrame);
           // We're reframing anyway; just keep the same context
           newContext = oldContext;
-          NS_ADDREF(newContext);
+          newContext->AddRef();
         }
       } else {
-        aPresContext->ResolvePseudoStyleContextFor(pseudoContent, pseudoTag,
-                                                   parentContext, 
-                                                   &newContext);
+        newContext = aPresContext->ResolvePseudoStyleContextFor(pseudoContent,
+                                                                pseudoTag,
+                                                                parentContext).get();
       }
-      NS_RELEASE(pseudoTag);
     }
     else {
       NS_ASSERTION(localContent,
                    "non pseudo-element frame without content node");
-      aPresContext->ResolveStyleContextFor(content, parentContext,
-                                           &newContext);
+      newContext = aPresContext->ResolveStyleContextFor(content, parentContext).get();
     }
     NS_ASSERTION(newContext, "failed to get new style context");
     if (newContext) {
@@ -1783,9 +1752,9 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
           // we can use FindChildWithRules to keep a lot of the old
           // style contexts around.  However, we need to start from the
           // same root.
-          NS_RELEASE(newContext);
+          newContext->Release();
           newContext = oldContext;
-          NS_ADDREF(newContext);
+          newContext->AddRef();
         }
       }
 
@@ -1816,7 +1785,7 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
           aChangeList.AppendChange(aFrame, content, NS_STYLE_HINT_REFLOW);
         }
       }
-      NS_RELEASE(oldContext);
+      oldContext->Release();
     }
     else {
       NS_ERROR("resolve style context failed");
@@ -1827,40 +1796,37 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
     // do additional contexts 
     PRInt32 contextIndex = -1;
     while (1 == 1) {
-      nsIStyleContext* oldExtraContext = nsnull;
-      result = aFrame->GetAdditionalStyleContext(++contextIndex, &oldExtraContext);
-      if (NS_SUCCEEDED(result)) {
-        if (oldExtraContext) {
-          nsIStyleContext* newExtraContext = nsnull;
-          oldExtraContext->GetPseudoType(pseudoTag);
-          NS_ASSERTION(pseudoTag &&
-                       pseudoTag != nsCSSAnonBoxes::mozNonElement,
-                       "extra style context is not pseudo element");
-          result = aPresContext->ResolvePseudoStyleContextFor(content, pseudoTag, newContext,
-                                                              &newExtraContext);
-          NS_RELEASE(pseudoTag);
-          if (NS_SUCCEEDED(result) && newExtraContext) {
-            if (oldExtraContext != newExtraContext) {
-              aMinChange = CaptureChange(oldExtraContext, newExtraContext, aFrame, 
-                                         content, aChangeList, aMinChange);
-              if (!(aMinChange & (nsChangeHint_ReconstructFrame | nsChangeHint_ReconstructDoc))) {
-                aFrame->SetAdditionalStyleContext(contextIndex, newExtraContext);
-              }
+      nsStyleContext* oldExtraContext = nsnull;
+      oldExtraContext = aFrame->GetAdditionalStyleContext(++contextIndex);
+      if (oldExtraContext) {
+        nsStyleContext* newExtraContext = nsnull;
+        pseudoTag = oldExtraContext->GetPseudoType();
+        NS_ASSERTION(pseudoTag &&
+                     pseudoTag != nsCSSAnonBoxes::mozNonElement,
+                     "extra style context is not pseudo element");
+        newExtraContext = aPresContext->ResolvePseudoStyleContextFor(content,
+                                                                     pseudoTag,
+                                                                     newContext).get();
+        if (newExtraContext) {
+          if (oldExtraContext != newExtraContext) {
+            aMinChange = CaptureChange(oldExtraContext, newExtraContext, aFrame, 
+                                       content, aChangeList, aMinChange);
+            if (!(aMinChange & (nsChangeHint_ReconstructFrame | nsChangeHint_ReconstructDoc))) {
+              aFrame->SetAdditionalStyleContext(contextIndex, newExtraContext);
             }
-            else {
-#if 0
-              // XXXldb |oldContext| is null by this point, so this will
-              // never do anything.
-              if (pseudoTag && pseudoTag != nsCSSAnonBoxes::mozNonElement &&
-                  aAttribute && (aMinChange < NS_STYLE_HINT_REFLOW) &&
-                  HasAttributeContent(oldContext, aAttrNameSpaceID, aAttribute)) {
-                aChangeList.AppendChange(aFrame, content, NS_STYLE_HINT_REFLOW);
-              }
-#endif
-            }
-            NS_RELEASE(newExtraContext);
           }
-          NS_RELEASE(oldExtraContext);
+          else {
+#if 0
+            // XXXldb |oldContext| is null by this point, so this will
+            // never do anything.
+            if (pseudoTag && pseudoTag != nsCSSAnonBoxes::mozNonElement &&
+                aAttribute && (aMinChange < NS_STYLE_HINT_REFLOW) &&
+                HasAttributeContent(oldContext, aAttrNameSpaceID, aAttribute)) {
+              aChangeList.AppendChange(aFrame, content, NS_STYLE_HINT_REFLOW);
+            }
+#endif
+          }
+          newExtraContext->Release();
         }
       }
       else {
@@ -1873,23 +1839,22 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
       for (UndisplayedNode* undisplayed =
                                    mUndisplayedMap->GetFirstNode(localContent);
            undisplayed; undisplayed = undisplayed->mNext) {
-        nsCOMPtr<nsIStyleContext> undisplayedContext;
-        undisplayed->mStyle->GetPseudoType(pseudoTag);
+        nsRefPtr<nsStyleContext> undisplayedContext;
+        pseudoTag = undisplayed->mStyle->GetPseudoType();
         if (pseudoTag == nsnull) {  // child content
-          aPresContext->ResolveStyleContextFor(undisplayed->mContent,
-                               newContext, getter_AddRefs(undisplayedContext));
+          undisplayedContext = aPresContext->ResolveStyleContextFor(undisplayed->mContent,
+                                                                    newContext).get();
         }
         else if (pseudoTag == nsCSSAnonBoxes::mozNonElement) {
-          aPresContext->ResolveStyleContextForNonElement(newContext, 
-                                           getter_AddRefs(undisplayedContext));
+          undisplayedContext = aPresContext->ResolveStyleContextForNonElement(newContext).get();
         }
         else {  // pseudo element
           NS_NOTREACHED("no pseudo elements in undisplayed map");
           NS_ASSERTION(pseudoTag, "pseudo element without tag");
-          aPresContext->ResolvePseudoStyleContextFor(localContent, pseudoTag,
-                               newContext, getter_AddRefs(undisplayedContext));
+          undisplayedContext = aPresContext->ResolvePseudoStyleContextFor(localContent,
+                                                                          pseudoTag,
+                                                                          newContext).get();
         }
-        NS_IF_RELEASE(pseudoTag);
         if (undisplayedContext) {
           const nsStyleDisplay* display;
           ::GetStyleData(undisplayedContext.get(), &display);
@@ -1925,11 +1890,9 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
                                                                 aPresContext);
           if (!beforeFrame) {
             // Look for a new :before style context
-            nsCOMPtr<nsIStyleContext> newBeforeContext;
-            aPresContext->ProbePseudoStyleContextFor(localContent,
+            nsRefPtr<nsStyleContext> newBeforeContext = aPresContext->ProbePseudoStyleContextFor(localContent,
                                                      nsCSSPseudoElements::before,
-                                                     newContext,
-                                                     getter_AddRefs(newBeforeContext));
+                                                     newContext);
             if (newBeforeContext) {
               // Have to create the new :before frame
               NS_UpdateHint(aMinChange, nsChangeHint_ReconstructFrame);
@@ -1952,11 +1915,9 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
           // Getting the :after frame is
           // more expensive than getting the pseudo context, so get the
           // pseudo context first.
-          nsCOMPtr<nsIStyleContext> newAfterContext;
-          aPresContext->ProbePseudoStyleContextFor(localContent,
+          nsRefPtr<nsStyleContext> newAfterContext = aPresContext->ProbePseudoStyleContextFor(localContent,
                                                    nsCSSPseudoElements::after,
-                                                   newContext,
-                                                   getter_AddRefs(newAfterContext));
+                                                   newContext);
           if (newAfterContext) {
             // Check whether we already have an :after frame
             nsIFrame* afterFrame = nsLayoutUtils::GetAfterFrame(aFrame,
@@ -2033,7 +1994,7 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
       // XXX need to do overflow frames???
     }
 
-    NS_RELEASE(newContext);
+    newContext->Release();
     NS_IF_RELEASE(localContent);
   }
 }
@@ -2667,7 +2628,7 @@ UndisplayedMap::AppendNodeFor(UndisplayedNode* aNode, nsIContent* aParentContent
 
 nsresult 
 UndisplayedMap::AddNodeFor(nsIContent* aParentContent, nsIContent* aChild, 
-                           nsIStyleContext* aStyle)
+                           nsStyleContext* aStyle)
 {
   UndisplayedNode*  node = new UndisplayedNode(aChild, aStyle);
   if (! node) {
diff --git a/mozilla/layout/html/base/src/nsGfxScrollFrame.cpp b/mozilla/layout/html/base/src/nsGfxScrollFrame.cpp
index ac4b86ef12e..e8b129923a4 100644
--- a/mozilla/layout/html/base/src/nsGfxScrollFrame.cpp
+++ b/mozilla/layout/html/base/src/nsGfxScrollFrame.cpp
@@ -470,7 +470,7 @@ NS_IMETHODIMP
 nsGfxScrollFrame::Init(nsIPresContext*  aPresContext,
                     nsIContent*      aContent,
                     nsIFrame*        aParent,
-                    nsIStyleContext* aStyleContext,
+                    nsStyleContext*  aStyleContext,
                     nsIFrame*        aPrevInFlow)
 {
   mPresContext = aPresContext;
diff --git a/mozilla/layout/html/base/src/nsGfxScrollFrame.h b/mozilla/layout/html/base/src/nsGfxScrollFrame.h
index 00f3e2c6566..5b0a31932a4 100644
--- a/mozilla/layout/html/base/src/nsGfxScrollFrame.h
+++ b/mozilla/layout/html/base/src/nsGfxScrollFrame.h
@@ -64,7 +64,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   virtual ~nsGfxScrollFrame();
diff --git a/mozilla/layout/html/base/src/nsHRFrame.cpp b/mozilla/layout/html/base/src/nsHRFrame.cpp
index e81abb6f08b..4aac9bd333e 100644
--- a/mozilla/layout/html/base/src/nsHRFrame.cpp
+++ b/mozilla/layout/html/base/src/nsHRFrame.cpp
@@ -39,10 +39,9 @@
 #include "nsIHTMLContent.h"
 #include "nsLeafFrame.h"
 #include "nsIRenderingContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsCSSColorUtils.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
 #include "nsHTMLAtoms.h"
 #include "nsIFontMetrics.h"
 #include "nsStyleConsts.h"
@@ -112,7 +111,7 @@ HRuleFrame::Paint(nsIPresContext*      aPresContext,
   }
 
   const nsStyleVisibility* vis = 
-      (const nsStyleVisibility*)((nsIStyleContext*)mStyleContext)->GetStyleData(eStyleStruct_Visibility);
+      (const nsStyleVisibility*)((nsStyleContext*)mStyleContext)->GetStyleData(eStyleStruct_Visibility);
   if (!vis->IsVisible()) {
     return NS_OK;
   }
diff --git a/mozilla/layout/html/base/src/nsHTMLContainerFrame.cpp b/mozilla/layout/html/base/src/nsHTMLContainerFrame.cpp
index 80837fe114e..874e4f7bfd2 100644
--- a/mozilla/layout/html/base/src/nsHTMLContainerFrame.cpp
+++ b/mozilla/layout/html/base/src/nsHTMLContainerFrame.cpp
@@ -38,7 +38,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresContext.h"
 #include "nsIPresShell.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIContent.h"
 #include "nsLayoutAtoms.h"
@@ -188,10 +188,9 @@ nsHTMLContainerFrame::GetTextDecorations(nsIPresContext* aPresContext,
     for (nsIFrame *frame = this; frame && decorMask; frame->GetParent(&frame)) {
       // find text-decorations.  "Inherit" from parent *block* frames
 
-      nsCOMPtr<nsIStyleContext> styleContext;
-      frame->GetStyleContext(getter_AddRefs(styleContext));
+      nsStyleContext* styleContext = frame->GetStyleContext();
       const nsStyleDisplay* styleDisplay;
-      ::GetStyleData(styleContext.get(), &styleDisplay);
+      ::GetStyleData(styleContext, &styleDisplay);
       if (!styleDisplay->IsBlockLevel() &&
           styleDisplay->mDisplay != NS_STYLE_DISPLAY_TABLE_CELL) {
         // If an inline frame is discovered while walking up the tree,
@@ -200,12 +199,12 @@ nsHTMLContainerFrame::GetTextDecorations(nsIPresContext* aPresContext,
         break;
       }
 
-      ::GetStyleData(styleContext.get(), &styleText);
+      ::GetStyleData(styleContext, &styleText);
       PRUint8 decors = decorMask & styleText->mTextDecoration;
       if (decors) {
         // A *new* text-decoration is found.
         const nsStyleColor* styleColor;
-        ::GetStyleData(styleContext.get(), &styleColor);
+        ::GetStyleData(styleContext, &styleColor);
 
         if (NS_STYLE_TEXT_DECORATION_UNDERLINE & decors) {
           aUnderColor = styleColor->mColor;
@@ -605,7 +604,7 @@ nsHTMLContainerFrame::ReparentFrameViewList(nsIPresContext* aPresContext,
 nsresult
 nsHTMLContainerFrame::CreateViewForFrame(nsIPresContext* aPresContext,
                                          nsIFrame* aFrame,
-                                         nsIStyleContext* aStyleContext,
+                                         nsStyleContext* aStyleContext,
                                          nsIFrame* aContentParentFrame,
                                          PRBool aForce)
 {
diff --git a/mozilla/layout/html/base/src/nsHTMLContainerFrame.h b/mozilla/layout/html/base/src/nsHTMLContainerFrame.h
index 9286da05dc0..2b45df58bb9 100644
--- a/mozilla/layout/html/base/src/nsHTMLContainerFrame.h
+++ b/mozilla/layout/html/base/src/nsHTMLContainerFrame.h
@@ -94,7 +94,7 @@ public:
    */
   static nsresult CreateViewForFrame(nsIPresContext* aPresContext,
                                      nsIFrame* aFrame,
-                                     nsIStyleContext* aStyleContext,
+                                     nsStyleContext* aStyleContext,
                                      nsIFrame* aContentParentFrame,
                                      PRBool aForce);
 
diff --git a/mozilla/layout/html/base/src/nsHTMLFrame.cpp b/mozilla/layout/html/base/src/nsHTMLFrame.cpp
index b5324332a0d..549422003b5 100644
--- a/mozilla/layout/html/base/src/nsHTMLFrame.cpp
+++ b/mozilla/layout/html/base/src/nsHTMLFrame.cpp
@@ -41,7 +41,7 @@
 #include "nsIDocument.h"
 #include "nsReflowPath.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsViewsCID.h"
 #include "nsIView.h"
 #include "nsIViewManager.h"
@@ -95,7 +95,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow);
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
 
@@ -223,7 +223,7 @@ NS_IMETHODIMP
 CanvasFrame::Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsHTMLContainerFrame::Init(aPresContext,aContent,aParent,aContext,aPrevInFlow);
diff --git a/mozilla/layout/html/base/src/nsHTMLReflowState.cpp b/mozilla/layout/html/base/src/nsHTMLReflowState.cpp
index 3e0d92bdbad..35b5cbf03c5 100644
--- a/mozilla/layout/html/base/src/nsHTMLReflowState.cpp
+++ b/mozilla/layout/html/base/src/nsHTMLReflowState.cpp
@@ -621,8 +621,7 @@ GetNearestContainingBlock(nsIFrame* aFrame, nsMargin& aContentArea)
     // it's percentage based (for example) then just ignore it
     nsStyleBorderPadding  bPad;
     nsMargin              borderPadding;
-    nsCOMPtr<nsIStyleContext> styleContext;
-    aFrame->GetStyleContext(getter_AddRefs(styleContext));
+    nsStyleContext* styleContext = aFrame->GetStyleContext();
     styleContext->GetBorderPaddingFor(bPad);
     if (bPad.GetBorderPadding(borderPadding)) {
       aContentArea.left += borderPadding.left;
@@ -2317,7 +2316,7 @@ GetNormalLineHeight(nsIFontMetrics* aFontMetrics)
 static nscoord
 ComputeLineHeight(nsIPresContext* aPresContext,
                   nsIRenderingContext* aRenderingContext,
-                  nsIStyleContext* aStyleContext)
+                  nsStyleContext* aStyleContext)
 {
   NS_PRECONDITION(nsnull != aRenderingContext, "no rendering context");
 
@@ -2377,8 +2376,7 @@ nsHTMLReflowState::CalcLineHeight(nsIPresContext* aPresContext,
                                   nsIFrame* aFrame)
 {
   nscoord lineHeight = -1;
-  nsCOMPtr<nsIStyleContext> sc;
-  aFrame->GetStyleContext(getter_AddRefs(sc));
+  nsStyleContext* sc = aFrame->GetStyleContext();
   if (sc) {
     lineHeight = ComputeLineHeight(aPresContext, aRenderingContext, sc);
   }
@@ -2427,8 +2425,7 @@ nsHTMLReflowState::ComputeHorizontalValue(nscoord aContainingBlockWidth,
       // pretend its zero...
     }
     else {
-      nsCOMPtr<nsIStyleContext> styleContext;
-      frame->GetStyleContext(getter_AddRefs(styleContext));
+      nsStyleContext* styleContext = frame->GetStyleContext();
       SetFontFromStyle(rendContext, styleContext);
       nscoord fontWidth;
       rendContext->GetWidth('M', fontWidth);
diff --git a/mozilla/layout/html/base/src/nsIAnonymousContentCreator.h b/mozilla/layout/html/base/src/nsIAnonymousContentCreator.h
index 6e563b221f2..2f0b0fa982a 100644
--- a/mozilla/layout/html/base/src/nsIAnonymousContentCreator.h
+++ b/mozilla/layout/html/base/src/nsIAnonymousContentCreator.h
@@ -46,7 +46,6 @@
 class nsIPresContext;
 class nsISupportsArray;
 class nsIAtom;
-class nsIStyleContext;
 class nsIFrame;
 
 
diff --git a/mozilla/layout/html/base/src/nsImageFrame.cpp b/mozilla/layout/html/base/src/nsImageFrame.cpp
index fb3282cd91f..280c90dc0f8 100644
--- a/mozilla/layout/html/base/src/nsImageFrame.cpp
+++ b/mozilla/layout/html/base/src/nsImageFrame.cpp
@@ -48,7 +48,7 @@
 #include "nsIHTMLContent.h"
 #include "nsIDocument.h"
 #include "nsINodeInfo.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsImageMap.h"
 #include "nsILinkHandler.h"
@@ -304,7 +304,7 @@ NS_IMETHODIMP
 nsImageFrame::Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        aPrevInFlow)
 {
   nsresult  rv = nsSplittableFrame::Init(aPresContext, aContent, aParent,
@@ -1296,7 +1296,7 @@ nsImageFrame::Paint(nsIPresContext*      aPresContext,
     // inline-level or block-level, respectively.  (See CSS2 9.5, which
     // is the rationale for paint layers.)
     const nsStyleDisplay *display;
-    ::GetStyleData(NS_STATIC_CAST(nsIStyleContext*, mStyleContext), &display);
+    ::GetStyleData(mStyleContext, &display);
     nsFramePaintLayer backgroundLayer = display->IsBlockLevel()
                                             ? NS_FRAME_PAINT_LAYER_BACKGROUND
                                             : NS_FRAME_PAINT_LAYER_FOREGROUND;
diff --git a/mozilla/layout/html/base/src/nsImageFrame.h b/mozilla/layout/html/base/src/nsImageFrame.h
index 3894960a5bd..fc1093f250e 100644
--- a/mozilla/layout/html/base/src/nsImageFrame.h
+++ b/mozilla/layout/html/base/src/nsImageFrame.h
@@ -96,7 +96,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   NS_IMETHOD Paint(nsIPresContext*      aPresContext,
                    nsIRenderingContext& aRenderingContext,
diff --git a/mozilla/layout/html/base/src/nsInlineFrame.cpp b/mozilla/layout/html/base/src/nsInlineFrame.cpp
index 1d38da366f3..a9bfa4786c7 100644
--- a/mozilla/layout/html/base/src/nsInlineFrame.cpp
+++ b/mozilla/layout/html/base/src/nsInlineFrame.cpp
@@ -39,7 +39,7 @@
 #include "nsBlockFrame.h"
 #include "nsHTMLAtoms.h"
 #include "nsHTMLParts.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIPresShell.h"
 #include "nsIPresContext.h"
 #include "nsIRenderingContext.h"
@@ -48,6 +48,7 @@
 #include "nsLayoutAtoms.h"
 #include "nsCSSAnonBoxes.h"
 #include "nsReflowPath.h"
+#include "nsAutoPtr.h"
 #ifdef ACCESSIBILITY
 #include "nsIServiceManager.h"
 #include "nsIAccessibilityService.h"
@@ -943,7 +944,7 @@ NS_IMETHODIMP nsInlineFrame::GetAccessible(nsIAccessible** aAccessible)
 
 static void
 ReParentChildListStyle(nsIPresContext* aPresContext,
-                       nsIStyleContext* aParentStyleContext,
+                       nsStyleContext* aParentStyleContext,
                        nsFrameList& aFrameList)
 {
   nsIFrame* kid = aFrameList.FirstChild();
@@ -1090,26 +1091,22 @@ nsFirstLineFrame::Reflow(nsIPresContext* aPresContext,
       // proper parent context.
       nsIFrame* parentFrame;
       first->GetParent(&parentFrame);
-      nsIStyleContext* parentContext;
-      parentFrame->GetStyleContext(&parentContext);
+      nsStyleContext* parentContext = parentFrame->GetStyleContext();
       if (parentContext) {
         // Create a new style context that is a child of the parent
         // style context thus removing the :first-line style. This way
         // we behave as if an anonymous (unstyled) span was the child
         // of the parent frame.
-        nsIStyleContext* newSC;
-        aPresContext->ResolvePseudoStyleContextFor(nsnull,
-                      nsCSSAnonBoxes::mozLineFrame, parentContext, &newSC);
+        nsRefPtr<nsStyleContext> newSC = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                                    nsCSSAnonBoxes::mozLineFrame,
+                                                                                    parentContext);
         if (newSC) {
           // Switch to the new style context.
           SetStyleContext(aPresContext, newSC);
 
           // Re-resolve all children
           ReParentChildListStyle(aPresContext, mStyleContext, mFrames);
-
-          NS_RELEASE(newSC);
         }
-        NS_RELEASE(parentContext);
       }
     }
   }
diff --git a/mozilla/layout/html/base/src/nsLineLayout.cpp b/mozilla/layout/html/base/src/nsLineLayout.cpp
index 1096a940843..c3507d52a10 100644
--- a/mozilla/layout/html/base/src/nsLineLayout.cpp
+++ b/mozilla/layout/html/base/src/nsLineLayout.cpp
@@ -45,7 +45,7 @@
 #include "nsStyleConsts.h"
 #include "nsHTMLContainerFrame.h"
 #include "nsSpaceManager.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIPresContext.h"
 #include "nsIFontMetrics.h"
 #include "nsIRenderingContext.h"
@@ -2097,8 +2097,7 @@ nsLineLayout::VerticalAlignFrames(PerSpanData* psd)
   nsIFrame* spanFrame = spanFramePFD->mFrame;
 
   // Get the parent frame's font for all of the frames in this span
-  nsCOMPtr<nsIStyleContext> styleContext;
-  spanFrame->GetStyleContext(getter_AddRefs(styleContext));
+  nsStyleContext* styleContext = spanFrame->GetStyleContext();
   nsIRenderingContext* rc = mBlockReflowState->rendContext;
   SetFontFromStyle(mBlockReflowState->rendContext, styleContext);
   nsCOMPtr<nsIFontMetrics> fm;
diff --git a/mozilla/layout/html/base/src/nsObjectFrame.cpp b/mozilla/layout/html/base/src/nsObjectFrame.cpp
index ee1b9d74308..e92e3b22ef5 100644
--- a/mozilla/layout/html/base/src/nsObjectFrame.cpp
+++ b/mozilla/layout/html/base/src/nsObjectFrame.cpp
@@ -118,7 +118,7 @@
 #include "nsIPrefService.h"
 
 // XXX For temporary paint code
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 
 // For mime types
 #include "nsMimeTypes.h"
@@ -577,7 +577,7 @@ NS_IMETHODIMP
 nsObjectFrame::Init(nsIPresContext*  aPresContext,
                     nsIContent*      aContent,
                     nsIFrame*        aParent,
-                    nsIStyleContext* aContext,
+                    nsStyleContext*  aContext,
                     nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsObjectFrameSuper::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/html/base/src/nsObjectFrame.h b/mozilla/layout/html/base/src/nsObjectFrame.h
index b931fdc351c..f924471bc6d 100644
--- a/mozilla/layout/html/base/src/nsObjectFrame.h
+++ b/mozilla/layout/html/base/src/nsObjectFrame.h
@@ -64,7 +64,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   NS_IMETHOD Reflow(nsIPresContext*          aPresContext,
                     nsHTMLReflowMetrics&     aDesiredSize,
diff --git a/mozilla/layout/html/base/src/nsPageContentFrame.cpp b/mozilla/layout/html/base/src/nsPageContentFrame.cpp
index 8d6d490815d..202746c761e 100644
--- a/mozilla/layout/html/base/src/nsPageContentFrame.cpp
+++ b/mozilla/layout/html/base/src/nsPageContentFrame.cpp
@@ -38,7 +38,6 @@
 #include "nsHTMLParts.h"
 #include "nsIContent.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
 #include "nsIRenderingContext.h"
 #include "nsHTMLAtoms.h"
 #include "nsLayoutAtoms.h"
diff --git a/mozilla/layout/html/base/src/nsPageFrame.cpp b/mozilla/layout/html/base/src/nsPageFrame.cpp
index 07c544b42ab..817d8956eb8 100644
--- a/mozilla/layout/html/base/src/nsPageFrame.cpp
+++ b/mozilla/layout/html/base/src/nsPageFrame.cpp
@@ -38,7 +38,7 @@
 #include "nsHTMLParts.h"
 #include "nsIContent.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIRenderingContext.h"
 #include "nsHTMLAtoms.h"
 #include "nsLayoutAtoms.h"
diff --git a/mozilla/layout/html/base/src/nsPlaceholderFrame.cpp b/mozilla/layout/html/base/src/nsPlaceholderFrame.cpp
index 49820fca39e..83ee0f7b7a1 100644
--- a/mozilla/layout/html/base/src/nsPlaceholderFrame.cpp
+++ b/mozilla/layout/html/base/src/nsPlaceholderFrame.cpp
@@ -39,7 +39,6 @@
 #include "nsIContent.h"
 #include "nsIPresContext.h"
 #include "nsIRenderingContext.h"
-#include "nsIStyleContext.h"
 #include "nsLayoutAtoms.h"
 
 nsresult
diff --git a/mozilla/layout/html/base/src/nsPresShell.cpp b/mozilla/layout/html/base/src/nsPresShell.cpp
index 175bcf7574a..360a5c61e86 100644
--- a/mozilla/layout/html/base/src/nsPresShell.cpp
+++ b/mozilla/layout/html/base/src/nsPresShell.cpp
@@ -79,6 +79,7 @@
 #include "nsHTMLAtoms.h"
 #include "nsCSSPseudoElements.h"
 #include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
 #include "nsReadableUtils.h"
 #include "nsUnicharUtils.h"
 #include "nsWeakReference.h"
@@ -1052,8 +1053,6 @@ public:
   NS_IMETHOD GetPrimaryFrameFor(nsIContent* aContent,
                                 nsIFrame**  aPrimaryFrame) const;
 
-  NS_IMETHOD GetStyleContextFor(nsIFrame*         aFrame,
-                                nsIStyleContext** aStyleContext) const;
   NS_IMETHOD GetLayoutObjectFor(nsIContent*   aContent,
                                 nsISupports** aResult) const;
   NS_IMETHOD GetPlaceholderFrameFor(nsIFrame*  aFrame,
@@ -4619,14 +4618,13 @@ PresShell::GetGeneratedContentIterator(nsIContent*          aContent,
     } else {
       // Avoid finding the :after frame unless we need to (it's
       // expensive). Instead probe for the existence of the pseudo-element
-      nsCOMPtr<nsIStyleContext> styleContext;
-      nsCOMPtr<nsIStyleContext> pseudoStyleContext;
+      nsStyleContext *styleContext;
+      nsRefPtr<nsStyleContext> pseudoStyleContext;
       
-      primaryFrame->GetStyleContext(getter_AddRefs(styleContext));
-      mPresContext->ProbePseudoStyleContextFor(aContent,
-                                               nsCSSPseudoElements::after,
-                                               styleContext,
-                                               getter_AddRefs(pseudoStyleContext));
+      styleContext = primaryFrame->GetStyleContext();
+      pseudoStyleContext = mPresContext->ProbePseudoStyleContextFor(aContent,
+                                                                    nsCSSPseudoElements::after,
+                                                                    styleContext);
       if (pseudoStyleContext) {
         nsIFrame* afterFrame = nsLayoutUtils::GetAfterFrame(primaryFrame,
                                                             mPresContext);
@@ -5558,16 +5556,6 @@ PresShell::GetPrimaryFrameFor(nsIContent* aContent,
   return rv;
 }
 
-NS_IMETHODIMP 
-PresShell::GetStyleContextFor(nsIFrame*         aFrame,
-                              nsIStyleContext** aStyleContext) const
-{
-  if (!aFrame || !aStyleContext) {
-    return NS_ERROR_NULL_POINTER;
-  }
-  return (aFrame->GetStyleContext(aStyleContext));
-}
-
 NS_IMETHODIMP
 PresShell::GetLayoutObjectFor(nsIContent*   aContent,
                               nsISupports** aResult) const 
diff --git a/mozilla/layout/html/base/src/nsScrollFrame.cpp b/mozilla/layout/html/base/src/nsScrollFrame.cpp
index 58e1e54c9bc..745f2795af6 100644
--- a/mozilla/layout/html/base/src/nsScrollFrame.cpp
+++ b/mozilla/layout/html/base/src/nsScrollFrame.cpp
@@ -92,7 +92,7 @@ NS_IMETHODIMP
 nsScrollFrame::Init(nsIPresContext*  aPresContext,
                     nsIContent*      aContent,
                     nsIFrame*        aParent,
-                    nsIStyleContext* aStyleContext,
+                    nsStyleContext*  aStyleContext,
                     nsIFrame*        aPrevInFlow)
 {
   nsresult  rv = nsHTMLContainerFrame::Init(aPresContext, aContent,
diff --git a/mozilla/layout/html/base/src/nsScrollFrame.h b/mozilla/layout/html/base/src/nsScrollFrame.h
index 6949811492c..c9065a3662e 100644
--- a/mozilla/layout/html/base/src/nsScrollFrame.h
+++ b/mozilla/layout/html/base/src/nsScrollFrame.h
@@ -60,7 +60,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   // Called to set the one and only child frame. Returns NS_ERROR_INVALID_ARG
diff --git a/mozilla/layout/html/base/src/nsSplittableFrame.cpp b/mozilla/layout/html/base/src/nsSplittableFrame.cpp
index abf0864dc48..2e201b1292d 100644
--- a/mozilla/layout/html/base/src/nsSplittableFrame.cpp
+++ b/mozilla/layout/html/base/src/nsSplittableFrame.cpp
@@ -37,14 +37,14 @@
 #include "nsSplittableFrame.h"
 #include "nsIContent.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsISizeOfHandler.h"
 
 NS_IMETHODIMP
 nsSplittableFrame::Init(nsIPresContext*  aPresContext,
                         nsIContent*      aContent,
                         nsIFrame*        aParent,
-                        nsIStyleContext* aContext,
+                        nsStyleContext*  aContext,
                         nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
diff --git a/mozilla/layout/html/base/src/nsSplittableFrame.h b/mozilla/layout/html/base/src/nsSplittableFrame.h
index cb402792b03..f2db6b93a61 100644
--- a/mozilla/layout/html/base/src/nsSplittableFrame.h
+++ b/mozilla/layout/html/base/src/nsSplittableFrame.h
@@ -46,7 +46,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   
   NS_IMETHOD  IsSplittable(nsSplittableType& aIsSplittable) const;
diff --git a/mozilla/layout/html/base/src/nsTextFrame.cpp b/mozilla/layout/html/base/src/nsTextFrame.cpp
index 8552b4f678e..9864ce512d5 100644
--- a/mozilla/layout/html/base/src/nsTextFrame.cpp
+++ b/mozilla/layout/html/base/src/nsTextFrame.cpp
@@ -50,7 +50,7 @@
 #include "nsIPresContext.h"
 #include "nsIContent.h"
 #include "nsStyleConsts.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsCoord.h"
 #include "nsIFontMetrics.h"
 #include "nsIRenderingContext.h"
@@ -91,6 +91,7 @@
 #include "nsIAccessibilityService.h"
 #endif
 #include "nsGUIEvent.h"
+#include "nsAutoPtr.h"
 
 #ifdef IBMBIDI
 #include "nsBidiFrames.h"
@@ -536,7 +537,7 @@ public:
 
     TextStyle(nsIPresContext* aPresContext,
               nsIRenderingContext& aRenderingContext,
-              nsIStyleContext* sc)
+              nsStyleContext* sc)
     {
     mFont = nsnull;
     mText = nsnull;
@@ -679,7 +680,7 @@ public:
                                         PRUnichar* aBuffer, PRInt32 aLength, PRInt32 aNumSpaces);
 
   void PaintTextDecorations(nsIRenderingContext& aRenderingContext,
-                            nsIStyleContext* aStyleContext,
+                            nsStyleContext* aStyleContext,
                             nsIPresContext* aPresContext,
                             TextStyle& aStyle,
                             nscoord aX, nscoord aY, nscoord aWidth,
@@ -691,12 +692,12 @@ public:
 
   void PaintTextSlowly(nsIPresContext* aPresContext,
                        nsIRenderingContext& aRenderingContext,
-                       nsIStyleContext* aStyleContext,
+                       nsStyleContext* aStyleContext,
                        TextStyle& aStyle,
                        nscoord aX, nscoord aY);
 
   void RenderString(nsIRenderingContext& aRenderingContext,
-                    nsIStyleContext* aStyleContext,
+                    nsStyleContext* aStyleContext,
                     nsIPresContext* aPresContext,
                     TextStyle& aStyle,
                     PRUnichar* aBuffer, PRInt32 aLength,
@@ -748,13 +749,13 @@ public:
 
   void PaintUnicodeText(nsIPresContext* aPresContext,
                         nsIRenderingContext& aRenderingContext,
-                        nsIStyleContext* aStyleContext,
+                        nsStyleContext* aStyleContext,
                         TextStyle& aStyle,
                         nscoord dx, nscoord dy);
 
   void PaintAsciiText(nsIPresContext* aPresContext,
                       nsIRenderingContext& aRenderingContext,
-                      nsIStyleContext* aStyleContext,
+                      nsStyleContext* aStyleContext,
                       TextStyle& aStyle,
                       nscoord dx, nscoord dy);
 
@@ -874,7 +875,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
@@ -901,7 +902,7 @@ NS_IMETHODIMP
 nsContinuingTextFrame::Init(nsIPresContext*  aPresContext,
                             nsIContent*      aContent,
                             nsIFrame*        aParent,
-                            nsIStyleContext* aContext,
+                            nsStyleContext*  aContext,
                             nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
@@ -1006,7 +1007,7 @@ public:
   DrawSelectionIterator(nsIContent *aContent, const SelectionDetails *aSelDetails, PRUnichar *aText,
                         PRUint32 aTextLength, nsTextFrame::TextStyle &aTextStyle,
                         PRInt16 aSelectionStatus, nsIPresContext *aPresContext,
-                        nsIStyleContext *aStyleContext);
+                        nsStyleContext *aStyleContext);
   ~DrawSelectionIterator();
   PRBool      First();
   PRBool      Next();
@@ -1051,7 +1052,7 @@ DrawSelectionIterator::DrawSelectionIterator(nsIContent *aContent,
                                              nsTextFrame::TextStyle &aTextStyle, 
                                              PRInt16 aSelectionStatus, 
                                              nsIPresContext *aPresContext,
-                                             nsIStyleContext *aStyleContext)
+                                             nsStyleContext *aStyleContext)
                                              :mOldStyle(aTextStyle)
 {
     mDetails = aSelDetails;
@@ -1065,13 +1066,13 @@ DrawSelectionIterator::DrawSelectionIterator(nsIContent *aContent,
     mSelectionPseudoBGIsTransparent = PR_FALSE;
 
     if (aContent) {
-      nsIStyleContext *sc = nsnull;
       nsCOMPtr<nsIContent> parentContent;
       aContent->GetParent(*getter_AddRefs(parentContent));
-      aPresContext->ProbePseudoStyleContextFor(parentContent,
-  					     nsCSSPseudoElements::mozSelection,
-  					     aStyleContext, &sc);
-      if (nsnull != sc) {
+      nsRefPtr<nsStyleContext> sc;
+      sc = aPresContext->ProbePseudoStyleContextFor(parentContent,
+						    nsCSSPseudoElements::mozSelection,
+						    aStyleContext);
+      if (sc) {
         mSelectionPseudoStyle = PR_TRUE;
         const nsStyleBackground* bg = (const nsStyleBackground*)sc->GetStyleData(eStyleStruct_Background);
         mSelectionPseudoBGIsTransparent = PRBool(bg->mBackgroundFlags & NS_STYLE_BG_COLOR_TRANSPARENT);
@@ -1079,7 +1080,6 @@ DrawSelectionIterator::DrawSelectionIterator(nsIContent *aContent,
           mSelectionPseudoBGcolor = bg->mBackgroundColor;
         const nsStyleColor* color =(const nsStyleColor*) sc->GetStyleData(eStyleStruct_Color);
         mSelectionPseudoFGcolor = color->mColor;
-        NS_RELEASE(sc);
       }
     }
 
@@ -1510,7 +1510,7 @@ nsTextFrame::Paint(nsIPresContext*      aPresContext,
   if ((0 != (mState & TEXT_BLINK_ON)) && nsBlinkTimer::GetBlinkIsOff()) {
     return NS_OK;
   }
-  nsIStyleContext* sc = mStyleContext;
+  nsStyleContext* sc = mStyleContext;
   PRBool isVisible;
   if (NS_SUCCEEDED(IsVisibleForPainting(aPresContext, aRenderingContext, PR_TRUE, &isVisible)) && isVisible) {
     TextStyle ts(aPresContext, aRenderingContext, mStyleContext);
@@ -1822,7 +1822,7 @@ RenderSelectionCursor(nsIRenderingContext& aRenderingContext,
 
 void 
 nsTextFrame::PaintTextDecorations(nsIRenderingContext& aRenderingContext,
-                                  nsIStyleContext* aStyleContext,
+                                  nsStyleContext* aStyleContext,
                                   nsIPresContext* aPresContext,
                                   TextStyle& aTextStyle,
                                   nscoord aX, nscoord aY, nscoord aWidth,
@@ -1849,19 +1849,19 @@ nsTextFrame::PaintTextDecorations(nsIRenderingContext& aRenderingContext,
     PRUint8 decorMask = NS_STYLE_TEXT_DECORATION_UNDERLINE | 
                         NS_STYLE_TEXT_DECORATION_OVERLINE |
                         NS_STYLE_TEXT_DECORATION_LINE_THROUGH;    
-    nsCOMPtr<nsIStyleContext> context = aStyleContext;
+    nsStyleContext* context = aStyleContext;
     PRBool hasDecorations = context->HasTextDecorations();
 
     while (hasDecorations) {
       const nsStyleTextReset* styleText;
-      ::GetStyleData(context.get(), &styleText);
+      ::GetStyleData(context, &styleText);
       if (!useOverride && 
           (NS_STYLE_TEXT_DECORATION_OVERRIDE_ALL & 
            styleText->mTextDecoration)) {
         // This handles the <a href="blah.html"><font color="green">La 
         // la la</font></a> case. The link underline should be green.
         const nsStyleColor* styleColor;
-        ::GetStyleData(context.get(), &styleColor);
+        ::GetStyleData(context, &styleColor);
         useOverride = PR_TRUE;
         overrideColor = styleColor->mColor;          
       }
@@ -1869,7 +1869,7 @@ nsTextFrame::PaintTextDecorations(nsIRenderingContext& aRenderingContext,
       PRUint8 useDecorations = decorMask & styleText->mTextDecoration;
       if (useDecorations) {// a decoration defined here
         const nsStyleColor* styleColor;
-        ::GetStyleData(context.get(), &styleColor);
+        ::GetStyleData(context, &styleColor);
     
         if (NS_STYLE_TEXT_DECORATION_UNDERLINE & useDecorations) {
           underColor = useOverride ? overrideColor : styleColor->mColor;
@@ -2293,7 +2293,7 @@ nsTextFrame::IsVisibleForPainting(nsIPresContext *     aPresContext,
 void
 nsTextFrame::PaintUnicodeText(nsIPresContext* aPresContext,
                               nsIRenderingContext& aRenderingContext,
-                              nsIStyleContext* aStyleContext,
+                              nsStyleContext* aStyleContext,
                               TextStyle& aTextStyle,
                               nscoord dx, nscoord dy)
 {
@@ -2698,7 +2698,7 @@ nsTextFrame::GetPositionSlowly(nsIPresContext* aPresContext,
 
 void
 nsTextFrame::RenderString(nsIRenderingContext& aRenderingContext,
-                          nsIStyleContext* aStyleContext,
+                          nsStyleContext* aStyleContext,
                           nsIPresContext* aPresContext,
                           TextStyle& aTextStyle,
                           PRUnichar* aBuffer, PRInt32 aLength,
@@ -3010,7 +3010,7 @@ nsTextFrame::ComputeExtraJustificationSpacing(nsIRenderingContext& aRenderingCon
 void
 nsTextFrame::PaintTextSlowly(nsIPresContext* aPresContext,
                              nsIRenderingContext& aRenderingContext,
-                             nsIStyleContext* aStyleContext,
+                             nsStyleContext* aStyleContext,
                              TextStyle& aTextStyle,
                              nscoord dx, nscoord dy)
 {
@@ -3197,7 +3197,7 @@ nsTextFrame::PaintTextSlowly(nsIPresContext* aPresContext,
 void
 nsTextFrame::PaintAsciiText(nsIPresContext* aPresContext,
                             nsIRenderingContext& aRenderingContext,
-                            nsIStyleContext* aStyleContext,
+                            nsStyleContext* aStyleContext,
                             TextStyle& aTextStyle,
                             nscoord dx, nscoord dy)
 {
@@ -6011,8 +6011,7 @@ nsTextFrame::ComputeWordFragmentDimensions(nsIPresContext* aPresContext,
   if((*aStop) && (wordLen == 0))
     return dimensions; // 0;
 
-  nsCOMPtr<nsIStyleContext> sc;
-  aTextFrame->GetStyleContext(getter_AddRefs(sc));
+  nsStyleContext* sc = aTextFrame->GetStyleContext();
   if (sc) {
     // Measure the piece of text. Note that we have to select the
     // appropriate font into the text first because the rendering
diff --git a/mozilla/layout/html/document/src/nsFrameFrame.cpp b/mozilla/layout/html/document/src/nsFrameFrame.cpp
index 4e0fbb94764..29b227f1d21 100644
--- a/mozilla/layout/html/document/src/nsFrameFrame.cpp
+++ b/mozilla/layout/html/document/src/nsFrameFrame.cpp
@@ -65,7 +65,7 @@
 #include "nsHTMLAtoms.h"
 #include "nsIScrollableView.h"
 #include "nsStyleCoord.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIDocumentLoader.h"
 #include "nsFrameSetFrame.h"
@@ -94,6 +94,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIFrameFrame.h"
 #include "nsIPluginViewer.h"
+#include "nsAutoPtr.h"
 
 // For Accessibility
 #ifdef ACCESSIBILITY
@@ -156,7 +157,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Reflow(nsIPresContext*          aPresContext,
@@ -240,7 +241,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   void GetParentContent(nsIContent** aContent);
@@ -338,7 +339,7 @@ NS_IMETHODIMP
 nsHTMLFrameOuterFrame::Init(nsIPresContext*  aPresContext,
                             nsIContent*      aContent,
                             nsIFrame*        aParent,
-                            nsIStyleContext* aContext,
+                            nsStyleContext*  aContext,
                             nsIFrame*        aPrevInFlow)
 {
   mPresContext = aPresContext;
@@ -412,16 +413,10 @@ nsHTMLFrameOuterFrame::Init(nsIPresContext*  aPresContext,
     mFrames.SetFrames(firstChild);
     // Resolve the style context for the inner frame
     nsresult rv = NS_OK;
-    nsIStyleContext *innerStyleContext = nsnull;
-    rv = aPresContext->ResolveStyleContextFor(mContent, mStyleContext,
-                                              &innerStyleContext);
-    if (NS_SUCCEEDED(rv)) {
-      rv = firstChild->Init(aPresContext, mContent, this, innerStyleContext, nsnull);
-      // have to release the context: Init does its own AddRef...
-      NS_RELEASE(innerStyleContext);
-    } else {
-      NS_WARNING( "Error resolving style for InnerFrame in nsHTMLFrameOuterFrame");
-    }
+    nsRefPtr<nsStyleContext> innerStyleContext;
+    innerStyleContext = aPresContext->ResolveStyleContextFor(mContent,
+                                                             mStyleContext);
+    rv = firstChild->Init(aPresContext, mContent, this, innerStyleContext, nsnull);
     if (NS_FAILED(rv)){
       NS_WARNING( "Error initializing InnerFrame in nsHTMLFrameOuterFrame");
       return rv;
@@ -1192,7 +1187,7 @@ NS_IMETHODIMP
 nsHTMLFrameInnerFrame::Init(nsIPresContext*  aPresContext,
                             nsIContent*      aContent,
                             nsIFrame*        aParent,
-                            nsIStyleContext* aContext,
+                            nsStyleContext*  aContext,
                             nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsLeafFrame::Init(aPresContext, aContent, aParent, aContext,
diff --git a/mozilla/layout/html/document/src/nsFrameSetFrame.cpp b/mozilla/layout/html/document/src/nsFrameSetFrame.cpp
index 013eff7993a..ca734b8be83 100644
--- a/mozilla/layout/html/document/src/nsFrameSetFrame.cpp
+++ b/mozilla/layout/html/document/src/nsFrameSetFrame.cpp
@@ -38,7 +38,7 @@
 #include "nsIScrollableView.h"
 #include "nsStyleCoord.h"
 #include "nsStyleConsts.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIDocumentLoader.h"
 #include "nsHTMLParts.h"
 #include "nsILookAndFeel.h"
@@ -54,6 +54,7 @@
 #include "nsINameSpaceManager.h"
 #include "nsCSSPseudoElements.h"
 #include "nsCSSAnonBoxes.h"
+#include "nsAutoPtr.h"
 
 // masks for mEdgeVisibility
 #define LEFT_VIS   0x0001
@@ -317,7 +318,7 @@ NS_IMETHODIMP
 nsHTMLFramesetFrame::Init(nsIPresContext*  aPresContext,
                           nsIContent*      aContent,
                           nsIFrame*        aParent,
-                          nsIStyleContext* aContext,
+                          nsStyleContext*  aContext,
                           nsIFrame*        aPrevInFlow)
 {
   nsHTMLContainerFrame::Init(aPresContext, aContent, aParent,
@@ -408,11 +409,10 @@ nsHTMLFramesetFrame::Init(nsIPresContext*  aPresContext,
     nsCOMPtr<nsIAtom> tag;
     child->GetTag(*getter_AddRefs(tag));
     if (tag == nsHTMLAtoms::frameset || tag == nsHTMLAtoms::frame) {
-      nsCOMPtr<nsIStyleContext> kidSC;
+      nsRefPtr<nsStyleContext> kidSC;
       nsresult result;
 
-      aPresContext->ResolveStyleContextFor(child, mStyleContext,
-                                           getter_AddRefs(kidSC));
+      kidSC = aPresContext->ResolveStyleContextFor(child, mStyleContext);
       if (tag == nsHTMLAtoms::frameset) {
         result = NS_NewHTMLFramesetFrame(shell, &frame);
 
@@ -453,10 +453,10 @@ nsHTMLFramesetFrame::Init(nsIPresContext*  aPresContext,
     // XXX the blank frame is using the content of its parent - at some point it 
     // should just have null content, if we support that
     nsHTMLFramesetBlankFrame* blankFrame = new (shell.get()) nsHTMLFramesetBlankFrame;
-    nsCOMPtr<nsIStyleContext> pseudoStyleContext;
-    aPresContext->ResolvePseudoStyleContextFor(nsnull,
-                            nsCSSAnonBoxes::framesetBlank, mStyleContext,
-                            getter_AddRefs(pseudoStyleContext));
+    nsRefPtr<nsStyleContext> pseudoStyleContext;
+    pseudoStyleContext = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                    nsCSSAnonBoxes::framesetBlank,
+                                                                    mStyleContext);
     if(blankFrame)
       blankFrame->Init(aPresContext, mContent, this, pseudoStyleContext, nsnull);
    
@@ -1080,12 +1080,11 @@ nsHTMLFramesetFrame::Reflow(nsIPresContext*          aPresContext,
       offset.y += lastSize.height;
       if (firstTime) { // create horizontal border
         borderFrame = new (shell.get()) nsHTMLFramesetBorderFrame(borderWidth, PR_FALSE, PR_FALSE);
-        nsIStyleContext* pseudoStyleContext;
-        aPresContext->ResolvePseudoStyleContextFor(mContent, nsCSSPseudoElements::horizontalFramesetBorder,
-                                                   mStyleContext,
-                                                   &pseudoStyleContext);
+        nsRefPtr<nsStyleContext> pseudoStyleContext;
+        pseudoStyleContext = aPresContext->ResolvePseudoStyleContextFor(mContent,
+                                                                        nsCSSPseudoElements::horizontalFramesetBorder,
+                                                                        mStyleContext);
         borderFrame->Init(aPresContext, mContent, this, pseudoStyleContext, nsnull);
-        NS_RELEASE(pseudoStyleContext);
 
         mChildCount++;
         lastChild->SetNextSibling(borderFrame);
@@ -1108,12 +1107,11 @@ nsHTMLFramesetFrame::Reflow(nsIPresContext*          aPresContext,
         if (0 == cellIndex.y) { // in 1st row
           if (firstTime) { // create vertical border
             borderFrame = new (shell.get()) nsHTMLFramesetBorderFrame(borderWidth, PR_TRUE, PR_FALSE);
-            nsIStyleContext* pseudoStyleContext;
-            aPresContext->ResolvePseudoStyleContextFor(mContent, nsCSSPseudoElements::verticalFramesetBorder,
-                                                       mStyleContext,
-                                                       &pseudoStyleContext);
+            nsRefPtr<nsStyleContext> pseudoStyleContext;
+            pseudoStyleContext = aPresContext->ResolvePseudoStyleContextFor(mContent,
+                                                                            nsCSSPseudoElements::verticalFramesetBorder,
+                                                                            mStyleContext);
             borderFrame->Init(aPresContext, mContent, this, pseudoStyleContext, nsnull);
-            NS_RELEASE(pseudoStyleContext);
 
             mChildCount++;
             lastChild->SetNextSibling(borderFrame);
diff --git a/mozilla/layout/html/document/src/nsFrameSetFrame.h b/mozilla/layout/html/document/src/nsFrameSetFrame.h
index 22abd4f6892..6426af8a062 100644
--- a/mozilla/layout/html/document/src/nsFrameSetFrame.h
+++ b/mozilla/layout/html/document/src/nsFrameSetFrame.h
@@ -120,7 +120,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   static PRBool  gDragInProgress;
diff --git a/mozilla/layout/html/forms/public/nsICheckboxControlFrame.h b/mozilla/layout/html/forms/public/nsICheckboxControlFrame.h
index e74b399816d..f22525fdeab 100644
--- a/mozilla/layout/html/forms/public/nsICheckboxControlFrame.h
+++ b/mozilla/layout/html/forms/public/nsICheckboxControlFrame.h
@@ -39,7 +39,7 @@
 #define nsICheckControlFrame_h___
 
 #include "nsISupports.h"
-class nsIStyleContext;
+class nsStyleContext;
 class nsIPresContext;
 
 // IID for the nsICheckControlFrame class
@@ -61,7 +61,7 @@ public:
    * Sets the Pseudo Style Contexts for the Check button
    */
   NS_IMETHOD SetCheckboxFaceStyleContext(
-                 nsIStyleContext* aCheckboxFaceStyleContext) = 0;
+                 nsStyleContext* aCheckboxFaceStyleContext) = 0;
   
   /**
    * Called by content when checkbox "checked" changes
diff --git a/mozilla/layout/html/forms/public/nsIRadioControlFrame.h b/mozilla/layout/html/forms/public/nsIRadioControlFrame.h
index 3da9d8674e1..d5f944bf287 100644
--- a/mozilla/layout/html/forms/public/nsIRadioControlFrame.h
+++ b/mozilla/layout/html/forms/public/nsIRadioControlFrame.h
@@ -39,7 +39,7 @@
 #define nsIRadioControlFrame_h___
 
 #include "nsISupports.h"
-class nsIStyleContext;
+class nsStyleContext;
 
 // IID for the nsIRadioControlFrame class
 // {06450E00-24D9-11d3-966B-00105A1B1B76}
@@ -61,7 +61,7 @@ public:
    * Sets the Pseudo Style Contexts for the Radio button
    */
 
-   NS_IMETHOD SetRadioButtonFaceStyleContext(nsIStyleContext *aRadioButtonFaceStyleContext) = 0;
+   NS_IMETHOD SetRadioButtonFaceStyleContext(nsStyleContext *aRadioButtonFaceStyleContext) = 0;
 
    /**
     * Called by content when the radio button's state changes
diff --git a/mozilla/layout/html/forms/src/nsButtonFrameRenderer.cpp b/mozilla/layout/html/forms/src/nsButtonFrameRenderer.cpp
index ac98d993321..51c05b6890a 100644
--- a/mozilla/layout/html/forms/src/nsButtonFrameRenderer.cpp
+++ b/mozilla/layout/html/forms/src/nsButtonFrameRenderer.cpp
@@ -145,7 +145,7 @@ nsButtonFrameRenderer::PaintOutlineAndFocusBorders(nsIPresContext* aPresContext,
     GetButtonOuterFocusRect(aRect, rect);
 
     const nsStyleBorder* border;
-    ::GetStyleData(NS_STATIC_CAST(nsIStyleContext*,mOuterFocusStyle), &border);
+    ::GetStyleData(mOuterFocusStyle, &border);
     nsCSSRendering::PaintBorder(aPresContext, aRenderingContext, mFrame,
                                 aDirtyRect, rect, *border, mOuterFocusStyle, 0);
   }
@@ -156,7 +156,7 @@ nsButtonFrameRenderer::PaintOutlineAndFocusBorders(nsIPresContext* aPresContext,
     GetButtonInnerFocusRect(aRect, rect);
 
     const nsStyleBorder* border;
-    ::GetStyleData(NS_STATIC_CAST(nsIStyleContext*,mInnerFocusStyle), &border);
+    ::GetStyleData(mInnerFocusStyle, &border);
     nsCSSRendering::PaintBorder(aPresContext, aRenderingContext, mFrame,
                                 aDirtyRect, rect, *border, mInnerFocusStyle, 0);
   }
@@ -174,8 +174,7 @@ nsButtonFrameRenderer::PaintBorderAndBackground(nsIPresContext* aPresContext,
   nsRect buttonRect;
   GetButtonRect(aRect, buttonRect);
 
-  nsCOMPtr<nsIStyleContext> context;
-  mFrame->GetStyleContext(getter_AddRefs(context));
+  nsStyleContext* context = mFrame->GetStyleContext();
 
   const nsStyleBorder* border =
     (const nsStyleBorder*)context->GetStyleData(eStyleStruct_Border);
@@ -247,8 +246,7 @@ nsButtonFrameRenderer::GetButtonOuterFocusBorderAndPadding()
 nsMargin
 nsButtonFrameRenderer::GetButtonBorderAndPadding()
 {
-  nsCOMPtr<nsIStyleContext> context;
-  mFrame->GetStyleContext(getter_AddRefs(context));
+  nsStyleContext* context = mFrame->GetStyleContext();
 
   nsMargin innerFocusBorderAndPadding(0,0,0,0);
   nsStyleBorderPadding  bPad;
@@ -324,52 +322,38 @@ nsButtonFrameRenderer::ReResolveStyles(nsIPresContext* aPresContext)
   // get all the styles
   nsCOMPtr<nsIContent> content;
   mFrame->GetContent(getter_AddRefs(content));
-  nsCOMPtr<nsIStyleContext> context;
-  mFrame->GetStyleContext(getter_AddRefs(context));
+  nsStyleContext* context = mFrame->GetStyleContext();
 
 
   // style for the inner such as a dotted line (Windows)
-  aPresContext->ProbePseudoStyleContextFor(content, nsCSSPseudoElements::mozFocusInner, context,
-                                          getter_AddRefs(mInnerFocusStyle));
+  mInnerFocusStyle = aPresContext->ProbePseudoStyleContextFor(content,
+                                                              nsCSSPseudoElements::mozFocusInner,
+                                                              context);
 
   // style for outer focus like a ridged border (MAC).
-  aPresContext->ProbePseudoStyleContextFor(content, nsCSSPseudoElements::mozFocusOuter, context,
-                                          getter_AddRefs(mOuterFocusStyle));
+  mOuterFocusStyle = aPresContext->ProbePseudoStyleContextFor(content,
+                                                              nsCSSPseudoElements::mozFocusOuter,
+                                                              context);
 
 }
 
-nsresult 
-nsButtonFrameRenderer::GetStyleContext(PRInt32 aIndex, nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsButtonFrameRenderer::GetStyleContext(PRInt32 aIndex) const
 {
-  NS_PRECONDITION(nsnull != aStyleContext, "null OUT parameter pointer");
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
-  *aStyleContext = nsnull;
   switch (aIndex) {
-
   case NS_BUTTON_RENDERER_FOCUS_INNER_CONTEXT_INDEX:
-    *aStyleContext = mInnerFocusStyle;
-    NS_IF_ADDREF(*aStyleContext);
-    break;
+    return mInnerFocusStyle;
   case NS_BUTTON_RENDERER_FOCUS_OUTER_CONTEXT_INDEX:
-    *aStyleContext = mOuterFocusStyle;
-    NS_IF_ADDREF(*aStyleContext);
-    break;
+    return mOuterFocusStyle;
   default:
-    return NS_ERROR_INVALID_ARG;
+    return nsnull;
   }
-  return NS_OK;
 }
 
-nsresult 
-nsButtonFrameRenderer::SetStyleContext(PRInt32 aIndex, nsIStyleContext* aStyleContext)
+void 
+nsButtonFrameRenderer::SetStyleContext(PRInt32 aIndex, nsStyleContext* aStyleContext)
 {
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
   switch (aIndex) {
- 
   case NS_BUTTON_RENDERER_FOCUS_INNER_CONTEXT_INDEX:
     mInnerFocusStyle = aStyleContext;
     break;
@@ -377,5 +361,4 @@ nsButtonFrameRenderer::SetStyleContext(PRInt32 aIndex, nsIStyleContext* aStyleCo
     mOuterFocusStyle = aStyleContext;
     break;
   }
-  return NS_OK;
 }
diff --git a/mozilla/layout/html/forms/src/nsButtonFrameRenderer.h b/mozilla/layout/html/forms/src/nsButtonFrameRenderer.h
index a5878958bfc..3e605c0139b 100644
--- a/mozilla/layout/html/forms/src/nsButtonFrameRenderer.h
+++ b/mozilla/layout/html/forms/src/nsButtonFrameRenderer.h
@@ -44,7 +44,7 @@
 #define nsButtonFrameRenderer_h___
 
 #include "nsCoord.h"
-#include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
 #include "nsFrame.h"
 
 class nsStyleChangeList;
@@ -98,8 +98,8 @@ public:
   virtual nsMargin GetFullButtonBorderAndPadding();
   virtual nsMargin GetAddedButtonBorderAndPadding();
 
-  virtual nsresult GetStyleContext(PRInt32 aIndex, nsIStyleContext** aStyleContext) const;
-  virtual nsresult SetStyleContext(PRInt32 aIndex, nsIStyleContext* aStyleContext);
+  virtual nsStyleContext* GetStyleContext(PRInt32 aIndex) const;
+  virtual void SetStyleContext(PRInt32 aIndex, nsStyleContext* aStyleContext);
 	virtual void ReResolveStyles(nsIPresContext* aPresContext);
 
   virtual void Redraw(nsIPresContext* aPresContext);
@@ -111,9 +111,9 @@ protected:
 private:
 
 	// cached styles for focus and outline.
-	nsCOMPtr<nsIStyleContext> mBorderStyle;
-	nsCOMPtr<nsIStyleContext> mInnerFocusStyle;
-	nsCOMPtr<nsIStyleContext> mOuterFocusStyle;
+  nsRefPtr<nsStyleContext> mBorderStyle;
+  nsRefPtr<nsStyleContext> mInnerFocusStyle;
+  nsRefPtr<nsStyleContext> mOuterFocusStyle;
 
 	nsFrame* mFrame;
 
diff --git a/mozilla/layout/html/forms/src/nsComboboxControlFrame.cpp b/mozilla/layout/html/forms/src/nsComboboxControlFrame.cpp
index b6802dc3e2d..0d8d6683bca 100644
--- a/mozilla/layout/html/forms/src/nsComboboxControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsComboboxControlFrame.cpp
@@ -83,6 +83,7 @@
 #include "nsIServiceManager.h"
 #include "nsIDOMNode.h"
 #include "nsGUIEvent.h"
+#include "nsAutoPtr.h"
 
 static NS_DEFINE_CID(kTextNodeCID,   NS_TEXTNODE_CID);
 static NS_DEFINE_CID(kHTMLElementFactoryCID,   NS_HTML_ELEMENT_FACTORY_CID);
@@ -376,7 +377,7 @@ NS_IMETHODIMP
 nsComboboxControlFrame::Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow)
 {
    // Need to hold on the pres context because it is used later in methods
@@ -2161,23 +2162,18 @@ nsComboboxControlFrame::CreateDisplayFrame(nsIPresContext* aPresContext)
   if (!mDisplayFrame) { return NS_ERROR_NULL_POINTER; }
 
   // create the style context for the anonymous frame
-  nsCOMPtr<nsIStyleContext> styleContext;
-  rv = aPresContext->ResolvePseudoStyleContextFor(mContent, 
+  nsRefPtr<nsStyleContext> styleContext;
+  styleContext = aPresContext->ResolvePseudoStyleContextFor(mContent, 
                                                   nsCSSAnonBoxes::mozDisplayComboboxControlFrame,
-                                                  mStyleContext,
-                                                  getter_AddRefs(styleContext));
-  if (NS_FAILED(rv)) { return rv; }
+                                                  mStyleContext);
   if (!styleContext) { return NS_ERROR_NULL_POINTER; }
 
   // create a text frame and put it inside the block frame
   rv = NS_NewTextFrame(shell, &mTextFrame);
   if (NS_FAILED(rv)) { return rv; }
   if (!mTextFrame) { return NS_ERROR_NULL_POINTER; }
-  nsCOMPtr<nsIStyleContext> textStyleContext;
-  rv = aPresContext->ResolveStyleContextForNonElement(
-                                             styleContext,
-                                             getter_AddRefs(textStyleContext));
-  if (NS_FAILED(rv)) { return rv; }
+  nsRefPtr<nsStyleContext> textStyleContext;
+  textStyleContext = aPresContext->ResolveStyleContextForNonElement(styleContext);
   if (!textStyleContext) { return NS_ERROR_NULL_POINTER; }
   nsCOMPtr<nsIContent> content(do_QueryInterface(mDisplayContent));
   mTextFrame->Init(aPresContext, content, mDisplayFrame, textStyleContext, nsnull);
@@ -2301,23 +2297,18 @@ nsComboboxControlFrame::CreateFrameFor(nsIPresContext*   aPresContext,
     if (!mDisplayFrame) { return NS_ERROR_NULL_POINTER; }
 
     // create the style context for the anonymous block frame
-    nsCOMPtr<nsIStyleContext> styleContext;
-    rv = aPresContext->ResolvePseudoStyleContextFor(mContent, 
+    nsRefPtr<nsStyleContext> styleContext;
+    styleContext = aPresContext->ResolvePseudoStyleContextFor(mContent, 
                                                     nsCSSAnonBoxes::mozDisplayComboboxControlFrame,
-                                                    mStyleContext,
-                                                    getter_AddRefs(styleContext));
-    if (NS_FAILED(rv)) { return rv; }
+                                                    mStyleContext);
     if (!styleContext) { return NS_ERROR_NULL_POINTER; }
 
     // Create a text frame and put it inside the block frame
     rv = NS_NewTextFrame(shell, &mTextFrame);
     if (NS_FAILED(rv)) { return rv; }
     if (!mTextFrame)   { return NS_ERROR_NULL_POINTER; }
-    nsCOMPtr<nsIStyleContext> textStyleContext;
-    rv = aPresContext->ResolveStyleContextForNonElement(
-                                             styleContext,
-                                             getter_AddRefs(textStyleContext));
-    if (NS_FAILED(rv))     { return rv; }
+    nsRefPtr<nsStyleContext> textStyleContext;
+    textStyleContext = aPresContext->ResolveStyleContextForNonElement(styleContext);
     if (!textStyleContext) { return NS_ERROR_NULL_POINTER; }
 
     // initialize the text frame
diff --git a/mozilla/layout/html/forms/src/nsComboboxControlFrame.h b/mozilla/layout/html/forms/src/nsComboboxControlFrame.h
index 1773ffa8aee..6057ab3eb6f 100644
--- a/mozilla/layout/html/forms/src/nsComboboxControlFrame.h
+++ b/mozilla/layout/html/forms/src/nsComboboxControlFrame.h
@@ -110,7 +110,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Reflow(nsIPresContext*          aCX,
diff --git a/mozilla/layout/html/forms/src/nsFieldSetFrame.cpp b/mozilla/layout/html/forms/src/nsFieldSetFrame.cpp
index 4ae7e35ea0e..5ab147cc0ff 100644
--- a/mozilla/layout/html/forms/src/nsFieldSetFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsFieldSetFrame.cpp
@@ -54,7 +54,6 @@
 #include "nsHTMLParts.h"
 #include "nsHTMLAtoms.h"
 #include "nsLayoutAtoms.h"
-#include "nsIStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsFont.h"
 #include "nsCOMPtr.h"
diff --git a/mozilla/layout/html/forms/src/nsFileControlFrame.h b/mozilla/layout/html/forms/src/nsFileControlFrame.h
index eb8f55817e1..f94f10e7c5d 100644
--- a/mozilla/layout/html/forms/src/nsFileControlFrame.h
+++ b/mozilla/layout/html/forms/src/nsFileControlFrame.h
@@ -65,7 +65,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow) {
     mPresContext = aPresContext;
     return nsAreaFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/html/forms/src/nsFormControlFrame.cpp b/mozilla/layout/html/forms/src/nsFormControlFrame.cpp
index e3de8dc461b..0438964bb6a 100644
--- a/mozilla/layout/html/forms/src/nsFormControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsFormControlFrame.cpp
@@ -41,7 +41,6 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresShell.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
 #include "nsLeafFrame.h"
 #include "nsCSSRendering.h"
 #include "nsIView.h"
diff --git a/mozilla/layout/html/forms/src/nsFormControlFrame.h b/mozilla/layout/html/forms/src/nsFormControlFrame.h
index 665f49030d3..d82d058d0f7 100644
--- a/mozilla/layout/html/forms/src/nsFormControlFrame.h
+++ b/mozilla/layout/html/forms/src/nsFormControlFrame.h
@@ -44,7 +44,6 @@
 #include "nsIWidget.h"
 #include "nsLeafFrame.h"
 #include "nsCoord.h"
-#include "nsIStyleContext.h"
 #include "nsIPresContext.h"
 #include "nsCOMPtr.h"
 
diff --git a/mozilla/layout/html/forms/src/nsFormControlHelper.cpp b/mozilla/layout/html/forms/src/nsFormControlHelper.cpp
index a81911af453..d299b496419 100644
--- a/mozilla/layout/html/forms/src/nsFormControlHelper.cpp
+++ b/mozilla/layout/html/forms/src/nsFormControlHelper.cpp
@@ -41,7 +41,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresShell.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsLeafFrame.h"
 #include "nsCSSRendering.h"
 #include "nsIView.h"
@@ -250,7 +250,7 @@ nsFormControlHelper::GetTextSize(nsIPresContext* aPresContext, nsIFormControlFra
 nsresult  
 nsFormControlHelper::GetFont(nsIFormControlFrame * aFormFrame,
                              nsIPresContext*       aPresContext, 
-                             nsIStyleContext *     aStyleContext, 
+                             nsStyleContext *      aStyleContext, 
                              const nsFont*&        aFont)
 {
   const nsStyleFont* styleFont = (const nsStyleFont*)aStyleContext->GetStyleData(eStyleStruct_Font);
diff --git a/mozilla/layout/html/forms/src/nsFormControlHelper.h b/mozilla/layout/html/forms/src/nsFormControlHelper.h
index 9b97d801213..e7f160cd15c 100644
--- a/mozilla/layout/html/forms/src/nsFormControlHelper.h
+++ b/mozilla/layout/html/forms/src/nsFormControlHelper.h
@@ -50,7 +50,7 @@ class nsIView;
 class nsIPresContext;
 class nsStyleCoord;
 class nsIPresState;
-class nsIStyleContext;
+class nsStyleContext;
 
 #define CSS_NOTSET -1
 #define ATTR_NOTSET -1
@@ -96,7 +96,7 @@ public:
   // XXX This could be removed now that we no longer have form quirks.
   static nsresult GetFont(nsIFormControlFrame *  aFormFrame,
                           nsIPresContext*        aPresContext, 
-                          nsIStyleContext *      aStyleContext, 
+                          nsStyleContext *       aStyleContext, 
                           const nsFont*&         aFont);
 
   // returns the an addref'ed FontMetrics for the default font for the frame
@@ -330,9 +330,9 @@ public:
                             const nsRect& aDirtyRect, const nsRect& aRect, 
                             PRBool aShift, PRBool aShowFocus, PRBool aDisabled,
 							              PRBool aDrawOutline,
-							              nsIStyleContext* aOutlineStyle,
-							              nsIStyleContext* aFocusStyle,
-                            nsIStyleContext* aStyleContext, nsString& aLabel, 
+							              nsStyleContext* aOutlineStyle,
+							              nsStyleContext* aFocusStyle,
+                            nsStyleContext* aStyleContext, nsString& aLabel, 
                             nsIFrame* aForFrame);
 
   static void StyleChangeReflow(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/html/forms/src/nsGfxButtonControlFrame.cpp b/mozilla/layout/html/forms/src/nsGfxButtonControlFrame.cpp
index 865694d659d..c321e1d2127 100644
--- a/mozilla/layout/html/forms/src/nsGfxButtonControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsGfxButtonControlFrame.cpp
@@ -50,6 +50,7 @@
 #include "nsIDOMNode.h"
 #include "nsLayoutAtoms.h"
 #include "nsReflowPath.h"
+#include "nsAutoPtr.h"
 // MouseEvent suppression in PP
 #include "nsGUIEvent.h"
 
@@ -253,17 +254,13 @@ nsGfxButtonControlFrame::CreateFrameFor(nsIPresContext*   aPresContext,
     aPresContext->GetShell(getter_AddRefs(shell));
 
     nsIFrame * parentFrame = mFrames.FirstChild();
-    nsCOMPtr<nsIStyleContext> styleContext;
-    parentFrame->GetStyleContext(getter_AddRefs(styleContext));
+    nsStyleContext* styleContext = parentFrame->GetStyleContext();
 
     rv = NS_NewTextFrame(shell, &newFrame);
     if (NS_FAILED(rv)) { return rv; }
     if (!newFrame)   { return NS_ERROR_NULL_POINTER; }
-    nsCOMPtr<nsIStyleContext> textStyleContext;
-    rv = aPresContext->ResolveStyleContextForNonElement(
-                                             styleContext,
-                                             getter_AddRefs(textStyleContext));
-    if (NS_FAILED(rv))     { return rv; }
+    nsRefPtr<nsStyleContext> textStyleContext;
+    textStyleContext = aPresContext->ResolveStyleContextForNonElement(styleContext);
     if (!textStyleContext) { return NS_ERROR_NULL_POINTER; }
 
     if (styleContext) {
diff --git a/mozilla/layout/html/forms/src/nsGfxCheckboxControlFrame.cpp b/mozilla/layout/html/forms/src/nsGfxCheckboxControlFrame.cpp
index 20d49fe67a8..1388f22b18a 100644
--- a/mozilla/layout/html/forms/src/nsGfxCheckboxControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsGfxCheckboxControlFrame.cpp
@@ -82,7 +82,8 @@ nsGfxCheckboxControlFrame::nsGfxCheckboxControlFrame()
 
 nsGfxCheckboxControlFrame::~nsGfxCheckboxControlFrame()
 {
-  NS_IF_RELEASE(mCheckButtonFaceStyle);
+  if (mCheckButtonFaceStyle)
+    mCheckButtonFaceStyle->Release();
 }
 
 
@@ -120,53 +121,43 @@ NS_IMETHODIMP nsGfxCheckboxControlFrame::GetAccessible(nsIAccessible** aAccessib
 
 //--------------------------------------------------------------
 NS_IMETHODIMP
-nsGfxCheckboxControlFrame::SetCheckboxFaceStyleContext(nsIStyleContext *aCheckboxFaceStyleContext)
+nsGfxCheckboxControlFrame::SetCheckboxFaceStyleContext(nsStyleContext *aCheckboxFaceStyleContext)
 {
   mCheckButtonFaceStyle = aCheckboxFaceStyleContext;
-  NS_ADDREF(mCheckButtonFaceStyle);
+  mCheckButtonFaceStyle->AddRef();
   return NS_OK;
 }
 
 
 //--------------------------------------------------------------
-NS_IMETHODIMP
-nsGfxCheckboxControlFrame::GetAdditionalStyleContext(PRInt32 aIndex, 
-                                                     nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsGfxCheckboxControlFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
 {
-  NS_PRECONDITION(nsnull != aStyleContext, "null OUT parameter pointer");
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
-  *aStyleContext = nsnull;
   switch (aIndex) {
   case NS_GFX_CHECKBOX_CONTROL_FRAME_FACE_CONTEXT_INDEX:
-    *aStyleContext = mCheckButtonFaceStyle;
-    NS_IF_ADDREF(*aStyleContext);
+    return mCheckButtonFaceStyle;
     break;
   default:
-    return NS_ERROR_INVALID_ARG;
+    return nsnull;
   }
-  return NS_OK;
 }
 
 
 
 //--------------------------------------------------------------
-NS_IMETHODIMP
+void
 nsGfxCheckboxControlFrame::SetAdditionalStyleContext(PRInt32 aIndex, 
-                                                     nsIStyleContext* aStyleContext)
+                                                     nsStyleContext* aStyleContext)
 {
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
   switch (aIndex) {
   case NS_GFX_CHECKBOX_CONTROL_FRAME_FACE_CONTEXT_INDEX:
-    NS_IF_RELEASE(mCheckButtonFaceStyle);
+    if (mCheckButtonFaceStyle)
+      mCheckButtonFaceStyle->Release();
     mCheckButtonFaceStyle = aStyleContext;
-    NS_IF_ADDREF(aStyleContext);
+    if (aStyleContext)
+      aStyleContext->AddRef();
     break;
   }
-  return NS_OK;
 }
 
 
diff --git a/mozilla/layout/html/forms/src/nsGfxCheckboxControlFrame.h b/mozilla/layout/html/forms/src/nsGfxCheckboxControlFrame.h
index 80e8bd7a67e..cdca5edde99 100644
--- a/mozilla/layout/html/forms/src/nsGfxCheckboxControlFrame.h
+++ b/mozilla/layout/html/forms/src/nsGfxCheckboxControlFrame.h
@@ -77,13 +77,12 @@ public:
 
 
   //nsICheckboxControlFrame methods
-  NS_IMETHOD SetCheckboxFaceStyleContext(nsIStyleContext *aCheckboxFaceStyleContext);
+  NS_IMETHOD SetCheckboxFaceStyleContext(nsStyleContext *aCheckboxFaceStyleContext);
   NS_IMETHOD OnChecked(nsIPresContext* aPresContext, PRBool aChecked);
 
-  NS_IMETHOD GetAdditionalStyleContext(PRInt32 aIndex, 
-                                       nsIStyleContext** aStyleContext) const;
-  NS_IMETHOD SetAdditionalStyleContext(PRInt32 aIndex, 
-                                       nsIStyleContext* aStyleContext);
+  virtual nsStyleContext* GetAdditionalStyleContext(PRInt32 aIndex) const;
+  virtual void SetAdditionalStyleContext(PRInt32 aIndex,
+                                         nsStyleContext* aStyleContext);
 
     // nsIFormControlFrame
   NS_IMETHOD OnContentReset();
@@ -110,7 +109,7 @@ protected:
 
   //GFX-rendered state variables
   PRBool           mInClickEvent;
-  nsIStyleContext* mCheckButtonFaceStyle;
+  nsStyleContext*  mCheckButtonFaceStyle;
 
 private:
   NS_IMETHOD_(nsrefcnt) AddRef() { return NS_OK; }
diff --git a/mozilla/layout/html/forms/src/nsGfxRadioControlFrame.cpp b/mozilla/layout/html/forms/src/nsGfxRadioControlFrame.cpp
index bb479832eef..8bf0401f39a 100644
--- a/mozilla/layout/html/forms/src/nsGfxRadioControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsGfxRadioControlFrame.cpp
@@ -77,7 +77,8 @@ nsGfxRadioControlFrame::nsGfxRadioControlFrame()
 
 nsGfxRadioControlFrame::~nsGfxRadioControlFrame()
 {
-  NS_IF_RELEASE(mRadioButtonFaceStyle);
+  if (mRadioButtonFaceStyle)
+    mRadioButtonFaceStyle->Release();
 }
 
 // Frames are not refcounted, no need to AddRef
@@ -110,50 +111,40 @@ NS_IMETHODIMP nsGfxRadioControlFrame::GetAccessible(nsIAccessible** aAccessible)
 #endif
 
 //--------------------------------------------------------------
-NS_IMETHODIMP
-nsGfxRadioControlFrame::GetAdditionalStyleContext(PRInt32 aIndex, 
-                                                  nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsGfxRadioControlFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
 {
-  NS_PRECONDITION(nsnull != aStyleContext, "null OUT parameter pointer");
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
-  *aStyleContext = nsnull;
   switch (aIndex) {
   case NS_GFX_RADIO_CONTROL_FRAME_FACE_CONTEXT_INDEX:
-    *aStyleContext = mRadioButtonFaceStyle;
-    NS_IF_ADDREF(*aStyleContext);
+    return mRadioButtonFaceStyle;
     break;
   default:
-    return NS_ERROR_INVALID_ARG;
+    return nsnull;
   }
-  return NS_OK;
 }
 
 //--------------------------------------------------------------
-NS_IMETHODIMP
+void
 nsGfxRadioControlFrame::SetAdditionalStyleContext(PRInt32 aIndex, 
-                                                  nsIStyleContext* aStyleContext)
+                                                  nsStyleContext* aStyleContext)
 {
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
   switch (aIndex) {
   case NS_GFX_RADIO_CONTROL_FRAME_FACE_CONTEXT_INDEX:
-    NS_IF_RELEASE(mRadioButtonFaceStyle);
+    if (mRadioButtonFaceStyle)
+      mRadioButtonFaceStyle->Release();
     mRadioButtonFaceStyle = aStyleContext;
-    NS_IF_ADDREF(aStyleContext);
+    if (aStyleContext)
+      aStyleContext->AddRef();
     break;
   }
-  return NS_OK;
 }
 
 //--------------------------------------------------------------
 NS_IMETHODIMP
-nsGfxRadioControlFrame::SetRadioButtonFaceStyleContext(nsIStyleContext *aRadioButtonFaceStyleContext)
+nsGfxRadioControlFrame::SetRadioButtonFaceStyleContext(nsStyleContext *aRadioButtonFaceStyleContext)
 {
   mRadioButtonFaceStyle = aRadioButtonFaceStyleContext;
-  NS_ADDREF(mRadioButtonFaceStyle);
+  mRadioButtonFaceStyle->AddRef();
   return NS_OK;
 }
 
diff --git a/mozilla/layout/html/forms/src/nsGfxRadioControlFrame.h b/mozilla/layout/html/forms/src/nsGfxRadioControlFrame.h
index b04f5debf6d..1d9a40b0dc8 100644
--- a/mozilla/layout/html/forms/src/nsGfxRadioControlFrame.h
+++ b/mozilla/layout/html/forms/src/nsGfxRadioControlFrame.h
@@ -62,16 +62,15 @@ public:
 
    //nsIRadioControlFrame methods
   NS_IMETHOD QueryInterface(const nsIID& aIID, void** aInstancePtr);
-  NS_IMETHOD SetRadioButtonFaceStyleContext(nsIStyleContext *aRadioButtonFaceStyleContext);
+  NS_IMETHOD SetRadioButtonFaceStyleContext(nsStyleContext *aRadioButtonFaceStyleContext);
 #ifdef ACCESSIBILITY
   NS_IMETHOD GetAccessible(nsIAccessible** aAccessible);
 #endif
   NS_IMETHOD OnChecked(nsIPresContext* aPresContext, PRBool aChecked);
 
-  NS_IMETHOD GetAdditionalStyleContext(PRInt32 aIndex, 
-                                       nsIStyleContext** aStyleContext) const;
-  NS_IMETHOD SetAdditionalStyleContext(PRInt32 aIndex, 
-                                       nsIStyleContext* aStyleContext);
+  virtual nsStyleContext* GetAdditionalStyleContext(PRInt32 aIndex) const;
+  virtual void SetAdditionalStyleContext(PRInt32 aIndex,
+                                         nsStyleContext* aStyleContext);
 
   NS_IMETHOD HandleEvent(nsIPresContext* aPresContext, 
                          nsGUIEvent* aEvent,
@@ -106,7 +105,7 @@ public:
 protected:
 
     //GFX-rendered state variables
-  nsIStyleContext* mRadioButtonFaceStyle;
+  nsStyleContext* mRadioButtonFaceStyle;
 
 private:
   NS_IMETHOD_(nsrefcnt) AddRef() { return NS_OK; }
diff --git a/mozilla/layout/html/forms/src/nsHTMLButtonControlFrame.cpp b/mozilla/layout/html/forms/src/nsHTMLButtonControlFrame.cpp
index d90f1f9a49f..ad4771d04d9 100644
--- a/mozilla/layout/html/forms/src/nsHTMLButtonControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsHTMLButtonControlFrame.cpp
@@ -47,7 +47,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresContext.h"
 #include "nsIPresShell.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsLeafFrame.h"
 #include "nsCSSRendering.h"
 #include "nsISupports.h"
@@ -123,7 +123,7 @@ NS_IMETHODIMP
 nsHTMLButtonControlFrame::Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow)
 {
   nsresult  rv = nsHTMLContainerFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
@@ -145,13 +145,11 @@ nsHTMLButtonControlFrame::Init(nsIPresContext*  aPresContext,
   mFrames.SetFrames(areaFrame);
 
   // Resolve style and initialize the frame
-  nsIStyleContext* styleContext;
-  aPresContext->ResolvePseudoStyleContextFor(mContent,
+  nsRefPtr<nsStyleContext> styleContext;
+  styleContext = aPresContext->ResolvePseudoStyleContextFor(mContent,
                                             nsCSSAnonBoxes::buttonContent,
-                                            mStyleContext,
-                                            &styleContext);
+                                            mStyleContext);
   mFrames.FirstChild()->Init(aPresContext, mContent, this, styleContext, nsnull);
-  NS_RELEASE(styleContext);                                           
 
   return rv;
 }
@@ -333,14 +331,14 @@ nsHTMLButtonControlFrame::SetInitialChildList(nsIPresContext* aPresContext,
   //
   nsCOMPtr<nsIPresShell> shell;
   nsCOMPtr<nsIFrameManager> frameManager;
-  nsCOMPtr<nsIStyleContext> newParentContext;
+  nsStyleContext* newParentContext;
   aPresContext->GetShell(getter_AddRefs(shell));
   if (shell) {
     shell->GetFrameManager(getter_AddRefs(frameManager));
   }
   // get the new parent context from the first child: that is the frame that the
   // subsequent children will be made children of
-  mFrames.FirstChild()->GetStyleContext(getter_AddRefs(newParentContext));
+  newParentContext = mFrames.FirstChild()->GetStyleContext();
 
   // Set the parent for each of the child frames
   for (nsIFrame* frame = aChildList; nsnull != frame; frame->GetNextSibling(&frame)) {
@@ -691,18 +689,17 @@ NS_IMETHODIMP nsHTMLButtonControlFrame::GetProperty(nsIAtom* aName, nsAString& a
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsHTMLButtonControlFrame::GetAdditionalStyleContext(PRInt32 aIndex, 
-                                                    nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsHTMLButtonControlFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
 {
-  return mRenderer.GetStyleContext(aIndex, aStyleContext);
+  return mRenderer.GetStyleContext(aIndex);
 }
 
-NS_IMETHODIMP
+void
 nsHTMLButtonControlFrame::SetAdditionalStyleContext(PRInt32 aIndex, 
-                                                    nsIStyleContext* aStyleContext)
+                                                    nsStyleContext* aStyleContext)
 {
-  return mRenderer.SetStyleContext(aIndex, aStyleContext);
+  mRenderer.SetStyleContext(aIndex, aStyleContext);
 }
 
 
diff --git a/mozilla/layout/html/forms/src/nsHTMLButtonControlFrame.h b/mozilla/layout/html/forms/src/nsHTMLButtonControlFrame.h
index 95a5f7c3c8a..037bee97364 100644
--- a/mozilla/layout/html/forms/src/nsHTMLButtonControlFrame.h
+++ b/mozilla/layout/html/forms/src/nsHTMLButtonControlFrame.h
@@ -48,7 +48,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresContext.h"
 #include "nsIPresShell.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsLeafFrame.h"
 #include "nsCSSRendering.h"
 #include "nsISupports.h"
@@ -102,13 +102,12 @@ public:
   NS_IMETHOD  Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        asPrevInFlow);
 
-  NS_IMETHOD  GetAdditionalStyleContext(PRInt32 aIndex, 
-                                        nsIStyleContext** aStyleContext) const;
-  NS_IMETHOD  SetAdditionalStyleContext(PRInt32 aIndex, 
-                                        nsIStyleContext* aStyleContext);
+  virtual nsStyleContext* GetAdditionalStyleContext(PRInt32 aIndex) const;
+  virtual void SetAdditionalStyleContext(PRInt32 aIndex, 
+                                         nsStyleContext* aStyleContext);
  
   NS_IMETHOD  AppendFrames(nsIPresContext* aPresContext,
                            nsIPresShell&   aPresShell,
diff --git a/mozilla/layout/html/forms/src/nsImageControlFrame.cpp b/mozilla/layout/html/forms/src/nsImageControlFrame.cpp
index e9aa0d5e4a2..c8208591e4c 100644
--- a/mozilla/layout/html/forms/src/nsImageControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsImageControlFrame.cpp
@@ -44,7 +44,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresContext.h"
 #include "nsIPresShell.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsLeafFrame.h"
 #include "nsCSSRendering.h"
 #include "nsIViewManager.h"
@@ -91,7 +91,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Reflow(nsIPresContext*          aPresContext,
@@ -260,7 +260,7 @@ NS_IMETHODIMP
 nsImageControlFrame::Init(nsIPresContext*  aPresContext,
                           nsIContent*      aContent,
                           nsIFrame*        aParent,
-                          nsIStyleContext* aContext,
+                          nsStyleContext*  aContext,
                           nsIFrame*        aPrevInFlow)
 {
   // call our base class
diff --git a/mozilla/layout/html/forms/src/nsIsIndexFrame.h b/mozilla/layout/html/forms/src/nsIsIndexFrame.h
index 4f615654b51..e595ef3123b 100644
--- a/mozilla/layout/html/forms/src/nsIsIndexFrame.h
+++ b/mozilla/layout/html/forms/src/nsIsIndexFrame.h
@@ -72,7 +72,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow) {
     mPresContext = aPresContext;
     return nsAreaFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/html/forms/src/nsListControlFrame.cpp b/mozilla/layout/html/forms/src/nsListControlFrame.cpp
index 99363b0f6f1..2ef29851dab 100644
--- a/mozilla/layout/html/forms/src/nsListControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsListControlFrame.cpp
@@ -1091,8 +1091,7 @@ nsListControlFrame::Reflow(nsIPresContext*          aPresContext,
       mPresContext->GetShell(getter_AddRefs(presShell));
       nsresult result = presShell->GetPrimaryFrameFor(option, &optFrame);
       if (NS_SUCCEEDED(result) && optFrame != nsnull) {
-        nsCOMPtr<nsIStyleContext> optStyle;
-        optFrame->GetStyleContext(getter_AddRefs(optStyle));
+        nsStyleContext* optStyle = optFrame->GetStyleContext();
         if (optStyle) {
           const nsStyleFont* styleFont = (const nsStyleFont*)optStyle->GetStyleData(eStyleStruct_Font);
           nsCOMPtr<nsIDeviceContext> deviceContext;
@@ -1751,7 +1750,7 @@ NS_IMETHODIMP
 nsListControlFrame::Init(nsIPresContext*  aPresContext,
                          nsIContent*      aContent,
                          nsIFrame*        aParent,
-                         nsIStyleContext* aContext,
+                         nsStyleContext*  aContext,
                          nsIFrame*        aPrevInFlow)
 {
   mPresContext = aPresContext;
diff --git a/mozilla/layout/html/forms/src/nsListControlFrame.h b/mozilla/layout/html/forms/src/nsListControlFrame.h
index f71b21e7ef0..897302b5db3 100644
--- a/mozilla/layout/html/forms/src/nsListControlFrame.h
+++ b/mozilla/layout/html/forms/src/nsListControlFrame.h
@@ -201,7 +201,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD DidReflow(nsIPresContext*           aPresContext, 
diff --git a/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp b/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
index dbf07098ab9..e50f0b19b51 100644
--- a/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
+++ b/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
@@ -114,6 +114,7 @@
 #include "nsCSSRendering.h"
 #include "nsISelectElement.h"
 #include "nsLayoutErrors.h"
+#include "nsAutoPtr.h"
 
 static NS_DEFINE_CID(kTextNodeCID,   NS_TEXTNODE_CID);
 static NS_DEFINE_CID(kHTMLElementFactoryCID,   NS_HTML_ELEMENT_FACTORY_CID);
@@ -1024,7 +1025,7 @@ AdjustOutOfFlowFrameParentPtrs(nsIPresContext*          aPresContext,
  */
 static void
 MoveChildrenTo(nsIPresContext*          aPresContext,
-               nsIStyleContext*         aNewParentSC,
+               nsStyleContext*          aNewParentSC,
                nsIFrame*                aNewParent,
                nsIFrame*                aFrameList,
                nsFrameConstructorState* aState)
@@ -1376,7 +1377,7 @@ nsCSSFrameConstructor::CreateGeneratedFrameFor(nsIPresContext*       aPresContex
                                                nsIDocument*          aDocument,
                                                nsIFrame*             aParentFrame,
                                                nsIContent*           aContent,
-                                               nsIStyleContext*      aStyleContext,
+                                               nsStyleContext*       aStyleContext,
                                                const nsStyleContent* aStyleContent,
                                                PRUint32              aContentIndex,
                                                nsIFrame**            aFrame)
@@ -1568,7 +1569,7 @@ nsCSSFrameConstructor::CreateGeneratedContentFrame(nsIPresShell*        aPresShe
                                                    nsFrameConstructorState& aState,
                                                    nsIFrame*        aFrame,
                                                    nsIContent*      aContent,
-                                                   nsIStyleContext* aStyleContext,
+                                                   nsStyleContext*  aStyleContext,
                                                    nsIAtom*         aPseudoElement,
                                                    nsIFrame**       aWrapperFrame,
                                                    nsIFrame**       aResult)
@@ -1579,9 +1580,10 @@ nsCSSFrameConstructor::CreateGeneratedContentFrame(nsIPresShell*        aPresShe
     return PR_FALSE;
 
   // Probe for the existence of the pseudo-element
-  nsCOMPtr<nsIStyleContext> pseudoStyleContext;
-  aPresContext->ProbePseudoStyleContextFor(aContent, aPseudoElement, aStyleContext,
-                                           getter_AddRefs(pseudoStyleContext));
+  nsRefPtr<nsStyleContext> pseudoStyleContext;
+  pseudoStyleContext = aPresContext->ProbePseudoStyleContextFor(aContent,
+                                                                aPseudoElement,
+                                                                aStyleContext);
 
   if (pseudoStyleContext) {
     const nsStyleDisplay* display;
@@ -1609,10 +1611,11 @@ nsCSSFrameConstructor::CreateGeneratedContentFrame(nsIPresShell*        aPresShe
               NS_NewInlineFrame(aPresShell, aWrapperFrame);
               wrapperPseudo = nsCSSAnonBoxes::mozGCWrapperInline;
             }        
-            nsCOMPtr<nsIStyleContext> parentSC = aStyleContext->GetParent(); 
-            nsCOMPtr<nsIStyleContext> wrapperSC;
-            aPresContext->ResolvePseudoStyleContextFor(nsnull, wrapperPseudo,
-                                          parentSC, getter_AddRefs(wrapperSC));
+            nsStyleContext* parentSC = aStyleContext->GetParent();
+            nsRefPtr<nsStyleContext> wrapperSC;
+            wrapperSC = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                   wrapperPseudo,
+                                                                   parentSC);
             // |aFrame| is already the correct parent.
             InitAndRestoreFrame(aPresContext, aState, aContent, aFrame,
                                 wrapperSC, nsnull, *aWrapperFrame);
@@ -1643,9 +1646,8 @@ nsCSSFrameConstructor::CreateGeneratedContentFrame(nsIPresShell*        aPresShe
 
         // Create another pseudo style context to use for all the generated child
         // frames
-        nsIStyleContext*  textStyleContext;
-        aPresContext->ResolveStyleContextForNonElement(pseudoStyleContext,
-                                                       &textStyleContext);
+        nsRefPtr<nsStyleContext> textStyleContext;
+        textStyleContext = aPresContext->ResolveStyleContextForNonElement(pseudoStyleContext);
 
         // Now create content objects (and child frames) for each value of the
         // 'content' property
@@ -1665,7 +1667,6 @@ nsCSSFrameConstructor::CreateGeneratedContentFrame(nsIPresShell*        aPresShe
           }
         }
   
-        NS_RELEASE(textStyleContext);
         if (childFrames.childList) {
           containerFrame->SetInitialChildList(aPresContext, nsnull, childFrames.childList);
         }
@@ -1683,7 +1684,7 @@ nsCSSFrameConstructor::CreateInputFrame(nsIPresShell    *aPresShell,
                                         nsIPresContext  *aPresContext,
                                         nsIContent      *aContent, 
                                         nsIFrame        *&aFrame,
-                                        nsIStyleContext *aStyleContext)
+                                        nsStyleContext  *aStyleContext)
 {
   nsCOMPtr<nsIFormControl> control = do_QueryInterface(aContent);
   NS_ASSERTION(control, "input is not an nsIFormControl!");
@@ -1991,18 +1992,17 @@ nsCSSFrameConstructor::CreatePseudoTableFrame(nsIPresShell*            aPresShel
                           ? aState.mPseudoFrames.mCellInner.mFrame : aParentFrameIn;
   if (!parentFrame) return rv;
 
-  nsCOMPtr<nsIStyleContext> parentStyle;
   nsCOMPtr<nsIContent>      parentContent;
-  nsCOMPtr<nsIStyleContext> childStyle;
+  nsStyleContext *parentStyle;
+  nsRefPtr<nsStyleContext> childStyle;
 
-  parentFrame->GetStyleContext(getter_AddRefs(parentStyle)); 
+  parentStyle = parentFrame->GetStyleContext(); 
   parentFrame->GetContent(getter_AddRefs(parentContent));   
 
   // create the SC for the inner table which will be the parent of the outer table's SC
-  aPresContext->ResolvePseudoStyleContextFor(parentContent,
-                                             nsCSSAnonBoxes::table,
-                                             parentStyle,
-                                             getter_AddRefs(childStyle));
+  childStyle = aPresContext->ResolvePseudoStyleContextFor(parentContent,
+                                                          nsCSSAnonBoxes::table,
+                                                          parentStyle);
 
   nsPseudoFrameData& pseudoOuter = aState.mPseudoFrames.mTableOuter;
   nsPseudoFrameData& pseudoInner = aState.mPseudoFrames.mTableInner;
@@ -2011,7 +2011,7 @@ nsCSSFrameConstructor::CreatePseudoTableFrame(nsIPresShell*            aPresShel
   PRBool pseudoParent;
   nsFrameItems items;
   rv = ConstructTableFrame(aPresShell, aPresContext, aState, parentContent,
-                           parentFrame, childStyle.get(), aTableCreator,
+                           parentFrame, childStyle, aTableCreator,
                            PR_TRUE, items, pseudoOuter.mFrame, 
                            pseudoInner.mFrame, pseudoParent);
 
@@ -2042,17 +2042,16 @@ nsCSSFrameConstructor::CreatePseudoRowGroupFrame(nsIPresShell*            aPresS
                           ? aState.mPseudoFrames.mTableInner.mFrame : aParentFrameIn;
   if (!parentFrame) return rv;
 
-  nsCOMPtr<nsIStyleContext> parentStyle;
   nsCOMPtr<nsIContent>      parentContent;
-  nsCOMPtr<nsIStyleContext> childStyle;
+  nsStyleContext *parentStyle;
+  nsRefPtr<nsStyleContext> childStyle;
 
-  parentFrame->GetStyleContext(getter_AddRefs(parentStyle)); 
+  parentStyle = parentFrame->GetStyleContext();
   parentFrame->GetContent(getter_AddRefs(parentContent));   
 
-  aPresContext->ResolvePseudoStyleContextFor(parentContent,
-                                             nsCSSAnonBoxes::tableRowGroup, 
-                                             parentStyle,
-                                             getter_AddRefs(childStyle));
+  childStyle = aPresContext->ResolvePseudoStyleContextFor(parentContent,
+                                                          nsCSSAnonBoxes::tableRowGroup, 
+                                                          parentStyle);
 
   nsPseudoFrameData& pseudo = aState.mPseudoFrames.mRowGroup;
 
@@ -2060,7 +2059,7 @@ nsCSSFrameConstructor::CreatePseudoRowGroupFrame(nsIPresShell*            aPresS
   PRBool pseudoParent;
   nsFrameItems items;
   rv = ConstructTableRowGroupFrame(aPresShell, aPresContext, aState, parentContent,
-                                   parentFrame, childStyle.get(), aTableCreator,
+                                   parentFrame, childStyle, aTableCreator,
                                    PR_TRUE, items, pseudo.mFrame, pseudoParent);
   if (NS_FAILED(rv)) return rv;
 
@@ -2088,17 +2087,16 @@ nsCSSFrameConstructor::CreatePseudoColGroupFrame(nsIPresShell*            aPresS
                           ? aState.mPseudoFrames.mTableInner.mFrame : aParentFrameIn;
   if (!parentFrame) return rv;
 
-  nsCOMPtr<nsIStyleContext> parentStyle;
   nsCOMPtr<nsIContent>      parentContent;
-  nsCOMPtr<nsIStyleContext> childStyle;
+  nsStyleContext *parentStyle;
+  nsRefPtr<nsStyleContext> childStyle;
 
-  parentFrame->GetStyleContext(getter_AddRefs(parentStyle)); 
+  parentStyle = parentFrame->GetStyleContext();
   parentFrame->GetContent(getter_AddRefs(parentContent));   
 
-  aPresContext->ResolvePseudoStyleContextFor(parentContent,
-                                             nsCSSAnonBoxes::tableColGroup, 
-                                             parentStyle,
-                                             getter_AddRefs(childStyle));
+  childStyle = aPresContext->ResolvePseudoStyleContextFor(parentContent,
+                                                          nsCSSAnonBoxes::tableColGroup, 
+                                                          parentStyle);
 
   nsPseudoFrameData& pseudo = aState.mPseudoFrames.mColGroup;
 
@@ -2106,7 +2104,7 @@ nsCSSFrameConstructor::CreatePseudoColGroupFrame(nsIPresShell*            aPresS
   PRBool pseudoParent;
   nsFrameItems items;
   rv = ConstructTableColGroupFrame(aPresShell, aPresContext, aState, parentContent,
-                                   parentFrame, childStyle.get(), aTableCreator,
+                                   parentFrame, childStyle, aTableCreator,
                                    PR_TRUE, items, pseudo.mFrame, pseudoParent);
   if (NS_FAILED(rv)) return rv;
   ((nsTableColGroupFrame*)pseudo.mFrame)->SetType(eColGroupAnonymousCol);
@@ -2132,17 +2130,16 @@ nsCSSFrameConstructor::CreatePseudoRowFrame(nsIPresShell*            aPresShell,
                           ? aState.mPseudoFrames.mRowGroup.mFrame : aParentFrameIn;
   if (!parentFrame) return rv;
 
-  nsCOMPtr<nsIStyleContext> parentStyle;
   nsCOMPtr<nsIContent>      parentContent;
-  nsCOMPtr<nsIStyleContext> childStyle;
+  nsStyleContext *parentStyle;
+  nsRefPtr<nsStyleContext> childStyle;
 
-  parentFrame->GetStyleContext(getter_AddRefs(parentStyle)); 
+  parentStyle = parentFrame->GetStyleContext();
   parentFrame->GetContent(getter_AddRefs(parentContent));   
 
-  aPresContext->ResolvePseudoStyleContextFor(parentContent,
-                                             nsCSSAnonBoxes::tableRow, 
-                                             parentStyle,
-                                             getter_AddRefs(childStyle));
+  childStyle = aPresContext->ResolvePseudoStyleContextFor(parentContent,
+                                                          nsCSSAnonBoxes::tableRow, 
+                                                          parentStyle);
 
   nsPseudoFrameData& pseudo = aState.mPseudoFrames.mRow;
 
@@ -2150,7 +2147,7 @@ nsCSSFrameConstructor::CreatePseudoRowFrame(nsIPresShell*            aPresShell,
   PRBool pseudoParent;
   nsFrameItems items;
   rv = ConstructTableRowFrame(aPresShell, aPresContext, aState, parentContent,
-                              parentFrame, childStyle.get(), aTableCreator,
+                              parentFrame, childStyle, aTableCreator,
                               PR_TRUE, items, pseudo.mFrame, pseudoParent);
   if (NS_FAILED(rv)) return rv;
 
@@ -2177,17 +2174,16 @@ nsCSSFrameConstructor::CreatePseudoCellFrame(nsIPresShell*            aPresShell
                           ? aState.mPseudoFrames.mRow.mFrame : aParentFrameIn;
   if (!parentFrame) return rv;
 
-  nsCOMPtr<nsIStyleContext> parentStyle;
   nsCOMPtr<nsIContent>      parentContent;
-  nsCOMPtr<nsIStyleContext> childStyle;
+  nsStyleContext *parentStyle;
+  nsRefPtr<nsStyleContext> childStyle;
 
-  parentFrame->GetStyleContext(getter_AddRefs(parentStyle)); 
+  parentStyle = parentFrame->GetStyleContext();
   parentFrame->GetContent(getter_AddRefs(parentContent));   
 
-  aPresContext->ResolvePseudoStyleContextFor(parentContent,
-                                             nsCSSAnonBoxes::tableCell, 
-                                             parentStyle,
-                                             getter_AddRefs(childStyle));
+  childStyle = aPresContext->ResolvePseudoStyleContextFor(parentContent,
+                                                          nsCSSAnonBoxes::tableCell, 
+                                                          parentStyle);
 
   nsPseudoFrameData& pseudoOuter = aState.mPseudoFrames.mCellOuter;
   nsPseudoFrameData& pseudoInner = aState.mPseudoFrames.mCellInner;
@@ -2196,7 +2192,7 @@ nsCSSFrameConstructor::CreatePseudoCellFrame(nsIPresShell*            aPresShell
   PRBool pseudoParent;
   nsFrameItems items;
   rv = ConstructTableCellFrame(aPresShell, aPresContext, aState, parentContent,
-                               parentFrame, childStyle.get(), aTableCreator,
+                               parentFrame, childStyle, aTableCreator,
                                PR_TRUE, items, pseudoOuter.mFrame, 
                                pseudoInner.mFrame, pseudoParent);
   if (NS_FAILED(rv)) return rv;
@@ -2528,7 +2524,7 @@ nsCSSFrameConstructor::ConstructTableFrame(nsIPresShell*            aPresShell,
                                            nsFrameConstructorState& aState,
                                            nsIContent*              aContent,
                                            nsIFrame*                aParentFrameIn,
-                                           nsIStyleContext*         aStyleContext,
+                                           nsStyleContext*          aStyleContext,
                                            nsTableCreator&          aTableCreator,
                                            PRBool                   aIsPseudo,
                                            nsFrameItems&            aChildItems,
@@ -2557,11 +2553,10 @@ nsCSSFrameConstructor::ConstructTableFrame(nsIPresShell*            aPresShell,
   }
 
   // create the pseudo SC for the outer table as a child of the inner SC
-  nsCOMPtr<nsIStyleContext> outerStyleContext;
-  aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                             nsCSSAnonBoxes::tableOuter,
-                                             aStyleContext,
-                                             getter_AddRefs(outerStyleContext));
+  nsRefPtr<nsStyleContext> outerStyleContext;
+  outerStyleContext = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                                 nsCSSAnonBoxes::tableOuter,
+                                                                 aStyleContext);
   
   // Init the table outer frame and see if we need to create a view, e.g.
   // the frame is absolutely positioned  
@@ -2610,7 +2605,7 @@ nsCSSFrameConstructor::ConstructTableCaptionFrame(nsIPresShell*            aPres
                                                   nsFrameConstructorState& aState,
                                                   nsIContent*              aContent,
                                                   nsIFrame*                aParentFrameIn,
-                                                  nsIStyleContext*         aStyleContext,
+                                                  nsStyleContext*          aStyleContext,
                                                   nsTableCreator&          aTableCreator,
                                                   nsFrameItems&            aChildItems,
                                                   nsIFrame*&               aNewFrame,
@@ -2656,7 +2651,7 @@ nsCSSFrameConstructor::ConstructTableRowGroupFrame(nsIPresShell*            aPre
                                                    nsFrameConstructorState& aState,
                                                    nsIContent*              aContent,
                                                    nsIFrame*                aParentFrameIn,
-                                                   nsIStyleContext*         aStyleContext,
+                                                   nsStyleContext*          aStyleContext,
                                                    nsTableCreator&          aTableCreator,
                                                    PRBool                   aIsPseudo,
                                                    nsFrameItems&            aChildItems,
@@ -2731,7 +2726,7 @@ nsCSSFrameConstructor::ConstructTableColGroupFrame(nsIPresShell*            aPre
                                                    nsFrameConstructorState& aState,
                                                    nsIContent*              aContent,
                                                    nsIFrame*                aParentFrameIn,
-                                                   nsIStyleContext*         aStyleContext,
+                                                   nsStyleContext*          aStyleContext,
                                                    nsTableCreator&          aTableCreator,
                                                    PRBool                   aIsPseudo,
                                                    nsFrameItems&            aChildItems,
@@ -2781,7 +2776,7 @@ nsCSSFrameConstructor::ConstructTableRowFrame(nsIPresShell*            aPresShel
                                               nsFrameConstructorState& aState,
                                               nsIContent*              aContent,
                                               nsIFrame*                aParentFrameIn,
-                                              nsIStyleContext*         aStyleContext,
+                                              nsStyleContext*          aStyleContext,
                                               nsTableCreator&          aTableCreator,
                                               PRBool                   aIsPseudo,
                                               nsFrameItems&            aChildItems,
@@ -2836,7 +2831,7 @@ nsCSSFrameConstructor::ConstructTableColFrame(nsIPresShell*            aPresShel
                                               nsFrameConstructorState& aState,
                                               nsIContent*              aContent,
                                               nsIFrame*                aParentFrameIn,
-                                              nsIStyleContext*         aStyleContext,
+                                              nsStyleContext*          aStyleContext,
                                               nsTableCreator&          aTableCreator,
                                               PRBool                   aIsPseudo,
                                               nsFrameItems&            aChildItems,
@@ -2860,8 +2855,7 @@ nsCSSFrameConstructor::ConstructTableColFrame(nsIPresShell*            aPresShel
   rv = aTableCreator.CreateTableColFrame(&aNewFrame); if (NS_FAILED(rv)) return rv;
   InitAndRestoreFrame(aPresContext, aState, aContent, parentFrame, aStyleContext, nsnull, aNewFrame);
   // if the parent frame was anonymous then reparent the style context
-  nsCOMPtr<nsIStyleContext> parentStyleContext;
-  parentFrame->GetStyleContext(getter_AddRefs(parentStyleContext));
+  nsStyleContext* parentStyleContext = parentFrame->GetStyleContext();
   if (aIsPseudoParent) {
     aPresContext->ReParentStyleContext(aNewFrame, parentStyleContext);
   }
@@ -2872,11 +2866,11 @@ nsCSSFrameConstructor::ConstructTableColFrame(nsIPresShell*            aPresShel
   if (cgContent) { 
     cgContent->GetSpan(&span);
     nsIFrame* lastCol = aNewFrame;
-    nsCOMPtr<nsIStyleContext> styleContext;
+    nsStyleContext* styleContext;
     for (PRInt32 spanX = 1; spanX < span; spanX++) {
       // The same content node should always resolve to the same style context.
       if (1 == spanX)
-        aNewFrame->GetStyleContext(getter_AddRefs(styleContext));
+        styleContext = aNewFrame->GetStyleContext();
       nsIFrame* newCol;
       rv = aTableCreator.CreateTableColFrame(&newCol); if (NS_FAILED(rv)) return rv;
       InitAndRestoreFrame(aPresContext, aState, aContent, parentFrame,
@@ -2908,7 +2902,7 @@ nsCSSFrameConstructor::ConstructTableCellFrame(nsIPresShell*            aPresShe
                                                nsFrameConstructorState& aState,
                                                nsIContent*              aContent,
                                                nsIFrame*                aParentFrameIn,
-                                               nsIStyleContext*         aStyleContext,
+                                               nsStyleContext*          aStyleContext,
                                                nsTableCreator&          aTableCreator,
                                                PRBool                   aIsPseudo,
                                                nsFrameItems&            aChildItems,
@@ -2953,11 +2947,10 @@ nsCSSFrameConstructor::ConstructTableCellFrame(nsIPresShell*            aPresShe
   }
   
   // Resolve pseudo style and initialize the body cell frame
-  nsCOMPtr<nsIStyleContext> innerPseudoStyle;
-  aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                             nsCSSAnonBoxes::cellContent,
-                                             aStyleContext,
-                                             getter_AddRefs(innerPseudoStyle));
+  nsRefPtr<nsStyleContext> innerPseudoStyle;
+  innerPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                                nsCSSAnonBoxes::cellContent,
+                                                                aStyleContext);
   InitAndRestoreFrame(aPresContext, aState, aContent, 
                       aNewCellOuterFrame, innerPseudoStyle, nsnull, aNewCellInnerFrame);
 
@@ -2998,7 +2991,7 @@ nsCSSFrameConstructor::MustGeneratePseudoParent(nsIPresContext*  aPresContext,
                                                 nsIFrame*        aParentFrame,
                                                 nsIAtom*         aTag,
                                                 nsIContent*      aContent,
-                                                nsIStyleContext* aStyleContext)
+                                                nsStyleContext*  aStyleContext)
 {
   if (!aStyleContext) return PR_FALSE;
 
@@ -3029,7 +3022,7 @@ nsCSSFrameConstructor::ConstructTableForeignFrame(nsIPresShell*            aPres
                                                   nsFrameConstructorState& aState,
                                                   nsIContent*              aContent,
                                                   nsIFrame*                aParentFrameIn,
-                                                  nsIStyleContext*         aStyleContext,
+                                                  nsStyleContext*          aStyleContext,
                                                   nsTableCreator&          aTableCreator,
                                                   nsFrameItems&            aChildItems,
                                                   nsIFrame*&               aNewFrame,
@@ -3116,8 +3109,7 @@ nsCSSFrameConstructor::TableProcessChildren(nsIPresShell*            aPresShell,
 
   nsCOMPtr<nsIAtom> parentFrameType;
   aParentFrame->GetFrameType(getter_AddRefs(parentFrameType));
-  nsCOMPtr<nsIStyleContext> parentStyleContext;
-  aParentFrame->GetStyleContext(getter_AddRefs(parentStyleContext));
+  nsStyleContext* parentStyleContext = aParentFrame->GetStyleContext();
 
   ChildIterator iter, last;
   for (ChildIterator::Init(aContent, &iter, &last);
@@ -3153,7 +3145,7 @@ nsCSSFrameConstructor::TableProcessChild(nsIPresShell*            aPresShell,
                                          nsIContent*              aParentContent,
                                          nsIFrame*                aParentFrame,
                                          nsIAtom*                 aParentFrameType,
-                                         nsIStyleContext*         aParentStyleContext,
+                                         nsStyleContext*          aParentStyleContext,
                                          nsTableCreator&          aTableCreator,
                                          nsFrameItems&            aChildItems,
                                          nsIFrame*&               aCaption)
@@ -3164,11 +3156,11 @@ nsCSSFrameConstructor::TableProcessChild(nsIPresShell*            aPresShell,
   PRBool isPseudoParent = PR_FALSE;
     
   nsIFrame* childFrame = nsnull;
-  nsCOMPtr<nsIStyleContext> childStyleContext;
+  nsRefPtr<nsStyleContext> childStyleContext;
 
   // Resolve the style context and get its display
-  ResolveStyleContext(aPresContext, aParentFrame, aChildContent,
-                      getter_AddRefs(childStyleContext));
+  childStyleContext = ResolveStyleContext(aPresContext, aParentFrame,
+                                          aChildContent);
   const nsStyleDisplay* styleDisplay = (const nsStyleDisplay*)
     childStyleContext->GetStyleData(eStyleStruct_Display);
 
@@ -3294,8 +3286,7 @@ nsCSSFrameConstructor:: GetDisplay(nsIFrame* aFrame)
   if (nsnull == aFrame) {
     return nsnull;
   }
-  nsCOMPtr<nsIStyleContext> styleContext;
-  aFrame->GetStyleContext(getter_AddRefs(styleContext));
+  nsStyleContext* styleContext = aFrame->GetStyleContext();
   const nsStyleDisplay* display = 
     (const nsStyleDisplay*)styleContext->GetStyleData(eStyleStruct_Display);
   return display;
@@ -3334,7 +3325,7 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
                                                 nsFrameConstructorState& aState,
                                                 nsIContent*              aDocElement,
                                                 nsIFrame*                aParentFrame,
-                                                nsIStyleContext*         aParentStyleContext,
+                                                nsStyleContext*          aParentStyleContext,
                                                 nsIFrame*&               aNewFrame)
 {
     // how the root frame hierarchy should look
@@ -3405,9 +3396,9 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
   }
 
   // --------- CREATE AREA OR BOX FRAME -------
-  nsCOMPtr<nsIStyleContext>  styleContext;
-  aPresContext->ResolveStyleContextFor(aDocElement, aParentStyleContext,
-                                       getter_AddRefs(styleContext));
+  nsRefPtr<nsStyleContext> styleContext;
+  styleContext = aPresContext->ResolveStyleContextFor(aDocElement,
+                                                      aParentStyleContext);
 
   const nsStyleDisplay*  display = (const nsStyleDisplay*)
         styleContext->GetStyleData(eStyleStruct_Display);
@@ -3432,10 +3423,8 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
     }
 
     if (resolveStyle) {
-      rv = ResolveStyleContext(aPresContext, aParentFrame, aDocElement,
-                               getter_AddRefs(styleContext));
-      if (NS_FAILED(rv))
-        return rv;
+      styleContext = ResolveStyleContext(aPresContext, aParentFrame,
+                                         aDocElement);
     }
   }
 
@@ -3454,19 +3443,18 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
   // build a scrollframe
   if ((!isPaginated || (isPaginated && printPreviewContext)) && isScrollable) {
     nsIFrame* newScrollFrame = nsnull;
-    nsCOMPtr<nsIStyleContext> newContext;
+    nsRefPtr<nsStyleContext> newContext;
 
-    BeginBuildingScrollFrame( aPresShell, aPresContext,
-                              aState,
-                              aDocElement,
-                              styleContext,
-                              aParentFrame,
-                              nsCSSAnonBoxes::scrolledContent,
-                              mDocument,
-                              PR_FALSE,
-                              scrollFrame,
-                              newContext,
-                              newScrollFrame);
+    newContext = BeginBuildingScrollFrame( aPresShell, aPresContext,
+                                           aState,
+                                           aDocElement,
+                                           styleContext,
+                                           aParentFrame,
+                                           nsCSSAnonBoxes::scrolledContent,
+                                           mDocument,
+                                           PR_FALSE,
+                                           scrollFrame,
+                                           newScrollFrame);
 
     styleContext = newContext;
     aParentFrame = newScrollFrame;
@@ -3484,7 +3472,7 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
       if (NS_FAILED(rv)) {
         return rv;
       }
-      contentFrame->GetStyleContext(getter_AddRefs(styleContext));
+      styleContext = contentFrame->GetStyleContext();
   } else {
         // otherwise build a box or a block
 #if defined(MOZ_SVG)
@@ -3663,11 +3651,11 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
   
   // --------- BUILD VIEWPORT -----------
   nsIFrame*                 viewportFrame = nsnull;
-  nsCOMPtr<nsIStyleContext> viewportPseudoStyle;
+  nsRefPtr<nsStyleContext> viewportPseudoStyle;
 
-  aPresContext->ResolvePseudoStyleContextFor(nsnull, nsCSSAnonBoxes::viewport,
-                                           nsnull,
-                                           getter_AddRefs(viewportPseudoStyle));
+  viewportPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                   nsCSSAnonBoxes::viewport,
+                                                                   nsnull);
 
   NS_NewViewportFrame(aPresShell, &viewportFrame);
 
@@ -3804,9 +3792,8 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
     NS_ASSERTION(!isXUL, "XUL documents should never be scrollable - see above");
 
     // see if the style is overflow: hidden, first on the document element
-    nsCOMPtr<nsIStyleContext> styleContext;
-    aPresContext->ResolveStyleContextFor(aDocElement, nsnull,
-                                         getter_AddRefs(styleContext));
+    nsRefPtr<nsStyleContext> styleContext;
+    styleContext = aPresContext->ResolveStyleContextFor(aDocElement, nsnull);
     if (styleContext) {
       const nsStyleDisplay* display = (const nsStyleDisplay*)
         styleContext->GetStyleData(eStyleStruct_Display);
@@ -3846,9 +3833,9 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
         }
       }      
       if (bodyElement) {
-        nsCOMPtr<nsIStyleContext> bodyContext;
-        aPresContext->ResolveStyleContextFor(bodyElement, styleContext,
-                                             getter_AddRefs(bodyContext));
+        nsRefPtr<nsStyleContext> bodyContext;
+        bodyContext = aPresContext->ResolveStyleContextFor(bodyElement,
+                                                           styleContext);
         if (bodyContext) {
           const nsStyleDisplay* display = (const nsStyleDisplay*)
             bodyContext->GetStyleData(eStyleStruct_Display);
@@ -3864,7 +3851,7 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
   }
 
   nsIFrame* newFrame = rootFrame;
-  nsCOMPtr<nsIStyleContext> rootPseudoStyle;
+  nsRefPtr<nsStyleContext> rootPseudoStyle;
   // we must create a state because if the scrollbars are GFX it needs the 
   // state to build the scrollbar frames.
   nsFrameConstructorState state(aPresContext,
@@ -3876,9 +3863,9 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
 
   // If paginated, make sure we don't put scrollbars in
   if (isPaginated && !printPreviewContext)
-    aPresContext->ResolvePseudoStyleContextFor(nsnull, rootPseudo,
-                                               viewportPseudoStyle,
-                                               getter_AddRefs(rootPseudoStyle));
+    rootPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                 rootPseudo,
+                                                                 viewportPseudoStyle);
   else if (isScrollable) {
 
       // Build the frame. We give it the content we are wrapping which is the document,
@@ -3886,27 +3873,25 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
       // frame and the scrollable view if one was created.
 
       // resolve a context for the scrollframe
-      nsCOMPtr<nsIStyleContext>  styleContext;
-      aPresContext->ResolvePseudoStyleContextFor(nsnull,
-                                                 nsCSSAnonBoxes::viewportScroll,
-                                                 viewportPseudoStyle,
-                                                 getter_AddRefs(styleContext));
+      nsRefPtr<nsStyleContext>  styleContext;
+      styleContext = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                nsCSSAnonBoxes::viewportScroll,
+                                                                viewportPseudoStyle);
 
 
       nsIFrame* newScrollableFrame = nsnull;
 
-      BeginBuildingScrollFrame( aPresShell,
-                                aPresContext,
-                                state,
-                                aDocElement,
-                                styleContext,
-                                viewportFrame,
-                                rootPseudo,
-                                mDocument,
-                                PR_TRUE,
-                                newFrame,
-                                rootPseudoStyle,
-                                newScrollableFrame);
+      rootPseudoStyle = BeginBuildingScrollFrame( aPresShell,
+                                                  aPresContext,
+                                                  state,
+                                                  aDocElement,
+                                                  styleContext,
+                                                  viewportFrame,
+                                                  rootPseudo,
+                                                  mDocument,
+                                                  PR_TRUE,
+                                                  newFrame,
+                                                  newScrollableFrame);
 
       // Inform the view manager about the root scrollable view
       nsIView* view = nsnull;
@@ -3928,19 +3913,18 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
   } else {
     // If no scrollbars and xul, don't build a scrollframe at all. 
     if (isXUL) {
-      aPresContext->ResolvePseudoStyleContextFor(nsnull, rootPseudo,
-                                                 viewportPseudoStyle,
-                                                 getter_AddRefs(rootPseudoStyle));
+      rootPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                   rootPseudo,
+                                                                   viewportPseudoStyle);
     } else {
       // if HTML the always create a scrollframe so anchors work. That way you can scroll to 
       // anchors even if we don't have scrollbars.
 
       // create a style context for the scrollport of the viewport
-      nsCOMPtr<nsIStyleContext> scrollPseudoStyle;
-      aPresContext->ResolvePseudoStyleContextFor(nsnull,
-                                                nsCSSAnonBoxes::scrolledContent,
-                                                viewportPseudoStyle,
-                                                getter_AddRefs(scrollPseudoStyle));
+      nsRefPtr<nsStyleContext> scrollPseudoStyle;
+      scrollPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                     nsCSSAnonBoxes::scrolledContent,
+                                                                     viewportPseudoStyle);
 
       // create scrollframe
       nsIFrame* scrollFrame = nsnull;
@@ -3950,9 +3934,9 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
       scrollFrame->Init(aPresContext, nsnull, parentFrame, scrollPseudoStyle, nsnull);
 
       // resolve a new style for the root frame
-      aPresContext->ResolvePseudoStyleContextFor(nsnull, rootPseudo,
-                                                 scrollPseudoStyle,
-                                                 getter_AddRefs(rootPseudoStyle));
+      rootPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                   rootPseudo,
+                                                                   scrollPseudoStyle);
 
       // Inform the view manager about the root scrollable view
       nsIView* view = nsnull;
@@ -3995,7 +3979,7 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
     // Create the first page
     // Set the initial child lists
     nsIFrame *pageFrame, *pageContentFrame;
-    ConstructPageFrame(aPresShell, aPresContext, rootFrame, nsnull, 
+    ConstructPageFrame(aPresShell, aPresContext, rootFrame, nsnull,
                        pageFrame, pageContentFrame);
     rootFrame->SetInitialChildList(aPresContext, nsnull, pageFrame);
 
@@ -4014,7 +3998,7 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
 }
 
 NS_IMETHODIMP
-nsCSSFrameConstructor::ConstructPageFrame(nsIPresShell*   aPresShell, 
+nsCSSFrameConstructor::ConstructPageFrame(nsIPresShell*   aPresShell,
                                           nsIPresContext* aPresContext,
                                           nsIFrame*       aParentFrame,
                                           nsIFrame*       aPrevPageFrame,
@@ -4026,13 +4010,12 @@ nsCSSFrameConstructor::ConstructPageFrame(nsIPresShell*   aPresShell,
   if (NS_FAILED(rv))
     return rv;
 
-  nsCOMPtr<nsIStyleContext> parentStyleContext;
-  aParentFrame->GetStyleContext(getter_AddRefs(parentStyleContext));
+  nsStyleContext* parentStyleContext = aParentFrame->GetStyleContext();
 
-  nsCOMPtr<nsIStyleContext> pagePseudoStyle;
-  aPresContext->ResolvePseudoStyleContextFor(nsnull, nsCSSAnonBoxes::page,
-                                             parentStyleContext,
-                                             getter_AddRefs(pagePseudoStyle));
+  nsRefPtr<nsStyleContext> pagePseudoStyle;
+  pagePseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                               nsCSSAnonBoxes::page,
+                                                               parentStyleContext);
   // Initialize the page frame and force it to have a view. This makes printing of
   // the pages easier and faster.
   aPageFrame->Init(aPresContext, nsnull, aParentFrame, pagePseudoStyle, aPrevPageFrame);
@@ -4043,10 +4026,10 @@ nsCSSFrameConstructor::ConstructPageFrame(nsIPresShell*   aPresShell,
 
   NS_NewPageContentFrame(aPresShell, &aPageContentFrame);
 
-  nsCOMPtr<nsIStyleContext> pageContentPseudoStyle;
-  aPresContext->ResolvePseudoStyleContextFor(nsnull, nsCSSAnonBoxes::pageContent,
-                                             pagePseudoStyle,
-                                             getter_AddRefs(pageContentPseudoStyle));
+  nsRefPtr<nsStyleContext> pageContentPseudoStyle;
+  pageContentPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                                      nsCSSAnonBoxes::pageContent,
+                                                                      pagePseudoStyle);
   // Initialize the page content frame and force it to have a view. Also make it the
   // containing block for fixed elements which are repeated on every page.
   aPageContentFrame->Init(aPresContext, nsnull, aPageFrame, pageContentPseudoStyle, nsnull);
@@ -4098,7 +4081,7 @@ nsCSSFrameConstructor::CreatePlaceholderFrameFor(nsIPresShell*    aPresShell,
                                                  nsIFrameManager* aFrameManager,
                                                  nsIContent*      aContent,
                                                  nsIFrame*        aFrame,
-                                                 nsIStyleContext* aStyleContext,
+                                                 nsStyleContext*  aStyleContext,
                                                  nsIFrame*        aParentFrame,
                                                  nsIFrame**       aPlaceholderFrame)
 {
@@ -4107,10 +4090,9 @@ nsCSSFrameConstructor::CreatePlaceholderFrameFor(nsIPresShell*    aPresShell,
 
   if (NS_SUCCEEDED(rv)) {
     // The placeholder frame gets a pseudo style context
-    nsCOMPtr<nsIStyleContext>  placeholderStyle;
-    nsCOMPtr<nsIStyleContext> parentContext = aStyleContext->GetParent();
-    aPresContext->ResolveStyleContextForNonElement(parentContext,
-                                             getter_AddRefs(placeholderStyle));
+    nsRefPtr<nsStyleContext> placeholderStyle;
+    nsStyleContext* parentContext = aStyleContext->GetParent();
+    placeholderStyle = aPresContext->ResolveStyleContextForNonElement(parentContext);
     placeholderFrame->Init(aPresContext, aContent, aParentFrame,
                            placeholderStyle, nsnull);
   
@@ -4183,7 +4165,7 @@ nsCSSFrameConstructor::ConstructRadioControlFrame(nsIPresShell*        aPresShel
                                                  nsIPresContext*  aPresContext,
                                                  nsIFrame*&   aNewFrame,
                                                  nsIContent*  aContent,
-                                                 nsIStyleContext* aStyleContext)
+                                                 nsStyleContext* aStyleContext)
 {
   nsresult rv = NS_OK;
 	if (GetFormElementRenderingMode(aPresContext, eWidgetType_Radio) == eWidgetRendering_Gfx)
@@ -4196,11 +4178,10 @@ nsCSSFrameConstructor::ConstructRadioControlFrame(nsIPresShell*        aPresShel
     return rv;
   }
 
-  nsCOMPtr<nsIStyleContext> radioStyle;
-  aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                             nsCSSAnonBoxes::radio,
-                                             aStyleContext,
-                                             getter_AddRefs(radioStyle));
+  nsRefPtr<nsStyleContext> radioStyle;
+  radioStyle = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                          nsCSSAnonBoxes::radio,
+                                                          aStyleContext);
   nsIRadioControlFrame* radio = nsnull;
   if (aNewFrame != nsnull && NS_SUCCEEDED(aNewFrame->QueryInterface(NS_GET_IID(nsIRadioControlFrame), (void**)&radio))) {
     radio->SetRadioButtonFaceStyleContext(radioStyle);
@@ -4214,7 +4195,7 @@ nsCSSFrameConstructor::ConstructCheckboxControlFrame(nsIPresShell*    aPresShell
                                                      nsIPresContext*  aPresContext,
                                                      nsIFrame*&       aNewFrame,
                                                      nsIContent*      aContent,
-                                                     nsIStyleContext* aStyleContext)
+                                                     nsStyleContext*  aStyleContext)
 {
   nsresult rv = NS_OK;
 	if (GetFormElementRenderingMode(aPresContext, eWidgetType_Checkbox) == eWidgetRendering_Gfx)
@@ -4227,9 +4208,10 @@ nsCSSFrameConstructor::ConstructCheckboxControlFrame(nsIPresShell*    aPresShell
     aNewFrame = nsnull;
   }
 
-  nsCOMPtr<nsIStyleContext> checkboxStyle;
-  aPresContext->ResolvePseudoStyleContextFor(aContent, nsCSSAnonBoxes::check, 
-                                             aStyleContext, getter_AddRefs(checkboxStyle));
+  nsRefPtr<nsStyleContext> checkboxStyle;
+  checkboxStyle = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                             nsCSSAnonBoxes::check, 
+                                                             aStyleContext);
   nsICheckboxControlFrame* checkbox = nsnull;
   if (aNewFrame != nsnull && 
       NS_SUCCEEDED(aNewFrame->QueryInterface(NS_GET_IID(nsICheckboxControlFrame), (void**)&checkbox))) {
@@ -4329,7 +4311,7 @@ nsCSSFrameConstructor::ConstructSelectFrame(nsIPresShell*        aPresShell,
                                             nsIContent*              aContent,
                                             nsIFrame*                aParentFrame,
                                             nsIAtom*                 aTag,
-                                            nsIStyleContext*         aStyleContext,
+                                            nsStyleContext*          aStyleContext,
                                             nsIFrame*&               aNewFrame,
                                             PRBool&                  aProcessChildren,
                                             PRBool                   aIsAbsolutelyPositioned,
@@ -4399,11 +4381,10 @@ nsCSSFrameConstructor::ConstructSelectFrame(nsIPresShell*        aPresShell,
       comboBox->SetDropDown(listFrame);
 
         // Resolve psuedo element style for the dropdown list 
-      nsCOMPtr<nsIStyleContext> listStyle;
-      rv = aPresContext->ResolvePseudoStyleContextFor(aContent, 
-                                              nsCSSAnonBoxes::dropDownList, 
-                                              aStyleContext,
-                                              getter_AddRefs(listStyle));
+      nsRefPtr<nsStyleContext> listStyle;
+      listStyle = aPresContext->ResolvePseudoStyleContextFor(aContent, 
+                                                             nsCSSAnonBoxes::dropDownList, 
+                                                             aStyleContext);
 
       // Initialize the scroll frame positioned. Note that it is NOT
       // initialized as absolutely positioned.
@@ -4511,7 +4492,7 @@ nsCSSFrameConstructor::InitializeSelectFrame(nsIPresShell*        aPresShell,
                                              nsIFrame*                scrolledFrame,
                                              nsIContent*              aContent,
                                              nsIFrame*                aParentFrame,
-                                             nsIStyleContext*         aStyleContext,
+                                             nsStyleContext*          aStyleContext,
                                              PRBool                   aIsAbsolutelyPositioned,
                                              PRBool                   aIsFixedPositioned,
                                              PRBool                   aCreateBlock)
@@ -4525,81 +4506,79 @@ nsCSSFrameConstructor::InitializeSelectFrame(nsIPresShell*        aPresShell,
     geometricParent = aState.mFixedItems.containingBlock;
   }
   
-  nsCOMPtr<nsIStyleContext> scrollPseudoStyle;
-  nsCOMPtr<nsIStyleContext> scrolledPseudoStyle;
+  nsRefPtr<nsStyleContext> scrolledPseudoStyle;
 
   
-    aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                  nsCSSAnonBoxes::scrolledContent,
-                                  aStyleContext,
-                                  getter_AddRefs(scrolledPseudoStyle));
+  scrolledPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                                   nsCSSAnonBoxes::scrolledContent,
+                                                                   aStyleContext);
 
-    InitAndRestoreFrame(aPresContext, aState, aContent, 
-                        geometricParent, aStyleContext, nsnull, scrollFrame);
+  InitAndRestoreFrame(aPresContext, aState, aContent, 
+                      geometricParent, aStyleContext, nsnull, scrollFrame);
 
-    // Initialize the frame and force it to have a view
-    // the scrolled frame is anonymous and does not have a content node
-    InitAndRestoreFrame(aPresContext, aState, aContent, 
-                        scrollFrame, scrolledPseudoStyle, nsnull, scrolledFrame);
+  // Initialize the frame and force it to have a view
+  // the scrolled frame is anonymous and does not have a content node
+  InitAndRestoreFrame(aPresContext, aState, aContent, 
+                      scrollFrame, scrolledPseudoStyle, nsnull, scrolledFrame);
 
-    nsHTMLContainerFrame::CreateViewForFrame(aPresContext, scrolledFrame,
+  nsHTMLContainerFrame::CreateViewForFrame(aPresContext, scrolledFrame,
                                            scrolledPseudoStyle, nsnull, PR_TRUE);
 
 
-    // The area frame is a floater container
-    PRBool haveFirstLetterStyle, haveFirstLineStyle;
-    HaveSpecialBlockStyle(aPresContext, aContent, aStyleContext,
-                          &haveFirstLetterStyle, &haveFirstLineStyle);
-    nsFrameConstructorSaveState floaterSaveState;
-    aState.PushFloaterContainingBlock(scrolledFrame, floaterSaveState,
-                                      haveFirstLetterStyle,
-                                      haveFirstLineStyle);
+  // The area frame is a floater container
+  PRBool haveFirstLetterStyle, haveFirstLineStyle;
+  HaveSpecialBlockStyle(aPresContext, aContent, aStyleContext,
+                        &haveFirstLetterStyle, &haveFirstLineStyle);
+  nsFrameConstructorSaveState floaterSaveState;
+  aState.PushFloaterContainingBlock(scrolledFrame, floaterSaveState,
+                                    haveFirstLetterStyle,
+                                    haveFirstLineStyle);
 
-    // Process children
-    nsFrameConstructorSaveState absoluteSaveState;
-    nsFrameItems                childItems;
-    PRBool                      isPositionedContainingBlock = aIsAbsolutelyPositioned ||
-                                                              aIsFixedPositioned;
+  // Process children
+  nsFrameConstructorSaveState absoluteSaveState;
+  nsFrameItems                childItems;
+  PRBool                      isPositionedContainingBlock = aIsAbsolutelyPositioned ||
+    aIsFixedPositioned;
 
-    if (isPositionedContainingBlock) {
-      // The area frame becomes a container for child frames that are
-      // absolutely positioned
-      aState.PushAbsoluteContainingBlock(aPresContext, scrolledFrame, absoluteSaveState);
-    }
-     
-    ProcessChildren(aPresShell, aPresContext, aState, aContent, scrolledFrame, PR_FALSE,
-                    childItems, PR_TRUE);
+  if (isPositionedContainingBlock) {
+    // The area frame becomes a container for child frames that are
+    // absolutely positioned
+    aState.PushAbsoluteContainingBlock(aPresContext, scrolledFrame, absoluteSaveState);
+  }
 
-    // if a select is being created with zero options we need to create
-    // a special pseudo frame so it can be sized as best it can
-    nsCOMPtr<nsIDOMHTMLSelectElement> selectElement;
-    nsresult result = aContent->QueryInterface(NS_GET_IID(nsIDOMHTMLSelectElement),
-                                                 (void**)getter_AddRefs(selectElement));
-    if (NS_SUCCEEDED(result) && selectElement) {
-      AddDummyFrameToSelect(aPresContext, aPresShell, aState,
-                            scrollFrame, scrolledFrame, &childItems,
-                            aContent, selectElement);
-    }
-    //////////////////////////////////////////////////
-    //////////////////////////////////////////////////
-    
-    // Set the scrolled frame's initial child lists
-    scrolledFrame->SetInitialChildList(aPresContext, nsnull, childItems.childList);
-    if (isPositionedContainingBlock && aState.mAbsoluteItems.childList) {
-      scrolledFrame->SetInitialChildList(aPresContext,
-                                         nsLayoutAtoms::absoluteList,
-                                         aState.mAbsoluteItems.childList);
-    }
+  ProcessChildren(aPresShell, aPresContext, aState, aContent, scrolledFrame, PR_FALSE,
+                  childItems, PR_TRUE);
 
-    if (aState.mFloatedItems.childList) {
-      scrolledFrame->SetInitialChildList(aPresContext,
-                                         nsLayoutAtoms::floaterList,
-                                         aState.mFloatedItems.childList);
-    }
+  // if a select is being created with zero options we need to create
+  // a special pseudo frame so it can be sized as best it can
+  nsCOMPtr<nsIDOMHTMLSelectElement> selectElement;
+  nsresult result = aContent->QueryInterface(NS_GET_IID(nsIDOMHTMLSelectElement),
+                                             (void**)getter_AddRefs(selectElement));
+  if (NS_SUCCEEDED(result) && selectElement) {
+    AddDummyFrameToSelect(aPresContext, aPresShell, aState,
+                          scrollFrame, scrolledFrame, &childItems,
+                          aContent, selectElement);
+  }
+  //////////////////////////////////////////////////
+  //////////////////////////////////////////////////
+
+  // Set the scrolled frame's initial child lists
+  scrolledFrame->SetInitialChildList(aPresContext, nsnull, childItems.childList);
+  if (isPositionedContainingBlock && aState.mAbsoluteItems.childList) {
+    scrolledFrame->SetInitialChildList(aPresContext,
+                                       nsLayoutAtoms::absoluteList,
+                                       aState.mAbsoluteItems.childList);
+  }
+
+  if (aState.mFloatedItems.childList) {
+    scrolledFrame->SetInitialChildList(aPresContext,
+                                       nsLayoutAtoms::floaterList,
+                                       aState.mFloatedItems.childList);
+  }
 
   // Set the scroll frame's initial child list
   scrollFrame->SetInitialChildList(aPresContext, nsnull, scrolledFrame);
-                                            
+
   return NS_OK;
 }
 
@@ -4615,7 +4594,7 @@ nsCSSFrameConstructor::ConstructFieldSetFrame(nsIPresShell*            aPresShel
                                               nsIContent*              aContent,
                                               nsIFrame*                aParentFrame,
                                               nsIAtom*                 aTag,
-                                              nsIStyleContext*         aStyleContext,
+                                              nsStyleContext*          aStyleContext,
                                               nsIFrame*&               aNewFrame,
                                               PRBool&                  aProcessChildren,
                                               PRBool                   aIsAbsolutelyPositioned,
@@ -4656,81 +4635,81 @@ nsCSSFrameConstructor::ConstructFieldSetFrame(nsIPresShell*            aPresShel
   NS_NewAreaFrame(shell, &areaFrame, NS_BLOCK_SPACE_MGR | NS_BLOCK_SHRINK_WRAP);
 
   // Resolve style and initialize the frame
-  nsIStyleContext* styleContext;
-  aPresContext->ResolvePseudoStyleContextFor(aContent, nsCSSAnonBoxes::fieldsetContent,
-                                             aStyleContext, &styleContext);
+  nsRefPtr<nsStyleContext> styleContext;
+  styleContext = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                            nsCSSAnonBoxes::fieldsetContent,
+                                                            aStyleContext);
   InitAndRestoreFrame(aPresContext, aState, aContent, 
                       newFrame, styleContext, nsnull, areaFrame);
 
-  NS_RELEASE(styleContext);          
   
 
-    // The area frame is a floater container
-    PRBool haveFirstLetterStyle, haveFirstLineStyle;
-    HaveSpecialBlockStyle(aPresContext, aContent, aStyleContext,
-                          &haveFirstLetterStyle, &haveFirstLineStyle);
-    nsFrameConstructorSaveState floaterSaveState;
-    aState.PushFloaterContainingBlock(areaFrame, floaterSaveState,
-                                      haveFirstLetterStyle,
-                                      haveFirstLineStyle);
+  // The area frame is a floater container
+  PRBool haveFirstLetterStyle, haveFirstLineStyle;
+  HaveSpecialBlockStyle(aPresContext, aContent, aStyleContext,
+                        &haveFirstLetterStyle, &haveFirstLineStyle);
+  nsFrameConstructorSaveState floaterSaveState;
+  aState.PushFloaterContainingBlock(areaFrame, floaterSaveState,
+                                    haveFirstLetterStyle,
+                                    haveFirstLineStyle);
 
-    // Process children
-    nsFrameConstructorSaveState absoluteSaveState;
-    nsFrameItems                childItems;
-    PRBool                      isPositionedContainingBlock = aIsAbsolutelyPositioned ||
-                                                              aIsFixedPositioned;
+  // Process children
+  nsFrameConstructorSaveState absoluteSaveState;
+  nsFrameItems                childItems;
+  PRBool                      isPositionedContainingBlock = aIsAbsolutelyPositioned ||
+    aIsFixedPositioned;
 
-    if (isPositionedContainingBlock) {
-      // The area frame becomes a container for child frames that are
-      // absolutely positioned
-      aState.PushAbsoluteContainingBlock(aPresContext, areaFrame, absoluteSaveState);
-    }
-     
-    ProcessChildren(aPresShell, aPresContext, aState, aContent, areaFrame, PR_FALSE,
-                    childItems, PR_TRUE);
+  if (isPositionedContainingBlock) {
+    // The area frame becomes a container for child frames that are
+    // absolutely positioned
+    aState.PushAbsoluteContainingBlock(aPresContext, areaFrame, absoluteSaveState);
+  }
 
-    static NS_DEFINE_IID(kLegendFrameCID, NS_LEGEND_FRAME_CID);
-    nsIFrame * child      = childItems.childList;
-    nsIFrame * previous   = nsnull;
-    nsIFrame* legendFrame = nsnull;
-    while (nsnull != child) {
-      nsresult result = child->QueryInterface(kLegendFrameCID, (void**)&legendFrame);
-      if (NS_SUCCEEDED(result) && legendFrame) {
-        if (nsnull != previous) {
-          nsIFrame * nxt;
-          legendFrame->GetNextSibling(&nxt);
-          previous->SetNextSibling(nxt);
-          areaFrame->SetNextSibling(legendFrame);
-          legendFrame->SetParent(newFrame);
-          legendFrame->SetNextSibling(nsnull);
-          break;
-        } else {
-          nsIFrame * nxt;
-          legendFrame->GetNextSibling(&nxt);
-          childItems.childList = nxt;
-          areaFrame->SetNextSibling(legendFrame);
-          legendFrame->SetParent(newFrame);
-          legendFrame->SetNextSibling(nsnull);
-          break;
-        }
+  ProcessChildren(aPresShell, aPresContext, aState, aContent, areaFrame, PR_FALSE,
+                  childItems, PR_TRUE);
+
+  static NS_DEFINE_IID(kLegendFrameCID, NS_LEGEND_FRAME_CID);
+  nsIFrame * child      = childItems.childList;
+  nsIFrame * previous   = nsnull;
+  nsIFrame* legendFrame = nsnull;
+  while (nsnull != child) {
+    nsresult result = child->QueryInterface(kLegendFrameCID, (void**)&legendFrame);
+    if (NS_SUCCEEDED(result) && legendFrame) {
+      if (nsnull != previous) {
+        nsIFrame * nxt;
+        legendFrame->GetNextSibling(&nxt);
+        previous->SetNextSibling(nxt);
+        areaFrame->SetNextSibling(legendFrame);
+        legendFrame->SetParent(newFrame);
+        legendFrame->SetNextSibling(nsnull);
+        break;
+      } else {
+        nsIFrame * nxt;
+        legendFrame->GetNextSibling(&nxt);
+        childItems.childList = nxt;
+        areaFrame->SetNextSibling(legendFrame);
+        legendFrame->SetParent(newFrame);
+        legendFrame->SetNextSibling(nsnull);
+        break;
       }
-      previous = child;
-      child->GetNextSibling(&child);
     }
+    previous = child;
+    child->GetNextSibling(&child);
+  }
 
-    // Set the scrolled frame's initial child lists
-    areaFrame->SetInitialChildList(aPresContext, nsnull, childItems.childList);
-    if (isPositionedContainingBlock && aState.mAbsoluteItems.childList) {
-      areaFrame->SetInitialChildList(aPresContext,
-                                         nsLayoutAtoms::absoluteList,
-                                         aState.mAbsoluteItems.childList);
-    }
+  // Set the scrolled frame's initial child lists
+  areaFrame->SetInitialChildList(aPresContext, nsnull, childItems.childList);
+  if (isPositionedContainingBlock && aState.mAbsoluteItems.childList) {
+    areaFrame->SetInitialChildList(aPresContext,
+                                   nsLayoutAtoms::absoluteList,
+                                   aState.mAbsoluteItems.childList);
+  }
 
-    if (aState.mFloatedItems.childList) {
-      areaFrame->SetInitialChildList(aPresContext,
-                                         nsLayoutAtoms::floaterList,
-                                         aState.mFloatedItems.childList);
-    }
+  if (aState.mFloatedItems.childList) {
+    areaFrame->SetInitialChildList(aPresContext,
+                                   nsLayoutAtoms::floaterList,
+                                   aState.mFloatedItems.childList);
+  }
 
   // Set the scroll frame's initial child list
   newFrame->SetInitialChildList(aPresContext, nsnull, areaFrame);
@@ -4750,7 +4729,7 @@ nsCSSFrameConstructor::ConstructTextFrame(nsIPresShell*            aPresShell,
                                           nsFrameConstructorState& aState,
                                           nsIContent*              aContent,
                                           nsIFrame*                aParentFrame,
-                                          nsIStyleContext*         aStyleContext,
+                                          nsStyleContext*          aStyleContext,
                                           nsFrameItems&            aFrameItems)
 {
   // process pending pseudo frames. whitespace doesn't have an effect.
@@ -4793,7 +4772,7 @@ nsCSSFrameConstructor::ConstructHTMLFrame(nsIPresShell*            aPresShell,
                                           nsIFrame*                aParentFrame,
                                           nsIAtom*                 aTag,
                                           PRInt32                  aNameSpaceID,
-                                          nsIStyleContext*         aStyleContext,
+                                          nsStyleContext*          aStyleContext,
                                           nsFrameItems&            aFrameItems)
 {
   // Ignore the tag if it's not HTML content
@@ -5404,7 +5383,7 @@ nsCSSFrameConstructor::ConstructXULFrame(nsIPresShell*            aPresShell,
                                          nsIFrame*                aParentFrame,
                                          nsIAtom*                 aTag,
                                          PRInt32                  aNameSpaceID,
-                                         nsIStyleContext*         aStyleContext,
+                                         nsStyleContext*          aStyleContext,
                                          nsFrameItems&            aFrameItems,
                                          PRBool                   aXBLBaseTag,
                                          PRBool&                  aHaltProcessing)
@@ -6041,18 +6020,17 @@ nsCSSFrameConstructor::ConstructXULFrame(nsIPresShell*            aPresShell,
 }
 #endif
 
-nsresult
+already_AddRefed<nsStyleContext>
 nsCSSFrameConstructor::BeginBuildingScrollFrame(nsIPresShell* aPresShell, 
                                                 nsIPresContext*         aPresContext,
                                                nsFrameConstructorState& aState,
                                                nsIContent*              aContent,
-                                               nsIStyleContext*         aContentStyle,
+                                               nsStyleContext*          aContentStyle,
                                                nsIFrame*                aParentFrame,
                                                nsIAtom*                 aScrolledPseudo,
                                                nsIDocument*             aDocument,
                                                PRBool                   aIsRoot,
                                                nsIFrame*&               aNewFrame,                                                                                             
-                                               nsCOMPtr<nsIStyleContext>& aScrolledChildStyle,
                                                nsIFrame*&               aScrollableFrame,
                                                nsIFrame*                aScrollPortFrame)
 {
@@ -6078,7 +6056,7 @@ nsCSSFrameConstructor::BeginBuildingScrollFrame(nsIPresShell* aPresShell,
 
   nsFrameItems anonymousItems;
 
-  nsCOMPtr<nsIStyleContext> contentStyle = dont_QueryInterface(aContentStyle);
+  nsRefPtr<nsStyleContext> contentStyle = aContentStyle;
 
   PRBool isGfx = HasGfxScrollbars();
 
@@ -6092,11 +6070,10 @@ nsCSSFrameConstructor::BeginBuildingScrollFrame(nsIPresShell* aPresShell,
     aNewFrame = gfxScrollFrame;
 
     // we used the style that was passed in. So resolve another one.
-    nsCOMPtr<nsIStyleContext> scrollPseudoStyle;
-    aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                              nsCSSAnonBoxes::scrolledContent,
-                                              contentStyle,
-                                              getter_AddRefs(scrollPseudoStyle));
+    nsRefPtr<nsStyleContext> scrollPseudoStyle;
+    scrollPseudoStyle = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                                   nsCSSAnonBoxes::scrolledContent,
+                                                                   contentStyle);
 
     contentStyle = scrollPseudoStyle;
     InitAndRestoreFrame(aPresContext, aState, aContent, 
@@ -6110,13 +6087,9 @@ nsCSSFrameConstructor::BeginBuildingScrollFrame(nsIPresShell* aPresShell,
                         parentFrame, contentStyle, nsnull, scrollFrame);
   }
 
-  // initialize the scrolled frame
-  nsCOMPtr<nsIStyleContext> scrolledPseudoStyle;
-  aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                          aScrolledPseudo,
-                                          contentStyle,
-                                          getter_AddRefs(scrolledPseudoStyle));
-
+  nsStyleContext* aScrolledChildStyle = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                                                   aScrolledPseudo,
+                                                                                   contentStyle).get();
 
   aScrollableFrame = scrollFrame;
   
@@ -6127,13 +6100,11 @@ nsCSSFrameConstructor::BeginBuildingScrollFrame(nsIPresShell* aPresShell,
   }
 
 
-  aScrolledChildStyle = scrolledPseudoStyle;
-
   if (printPreviewContext && noScalingOfTwips) {
     printPreviewContext->SetScalingOfTwips(PR_TRUE);
   }
 
-  return NS_OK;
+  return aScrolledChildStyle;;
 }
 
 nsresult
@@ -6142,7 +6113,7 @@ nsCSSFrameConstructor::FinishBuildingScrollFrame(nsIPresContext*      aPresConte
                                              nsIContent*              aContent,
                                              nsIFrame*                aScrollFrame,
                                              nsIFrame*                aScrolledFrame,
-                                             nsIStyleContext*         aScrolledContentStyle)
+                                             nsStyleContext*          aScrolledContentStyle)
                                              
 {
   // create a view
@@ -6213,11 +6184,11 @@ nsCSSFrameConstructor::BuildScrollFrame       (nsIPresShell* aPresShell,
                                                nsIPresContext*          aPresContext,
                                                nsFrameConstructorState& aState,
                                                nsIContent*              aContent,
-                                               nsIStyleContext*         aContentStyle,
+                                               nsStyleContext*          aContentStyle,
                                                nsIFrame*                aScrolledFrame,
                                                nsIFrame*                aParentFrame,
                                                nsIFrame*&               aNewFrame, 
-                                               nsIStyleContext*&        aScrolledContentStyle,
+                                               nsStyleContext*&         aScrolledContentStyle,
                                                nsIFrame*                aScrollPortFrame)                                                                                                                                          
 {
     // Check to see the type of parent frame so we know whether we need to 
@@ -6238,21 +6209,20 @@ nsCSSFrameConstructor::BuildScrollFrame       (nsIPresShell* aPresShell,
 
     nsIFrame *scrollFrame;
 
-    nsCOMPtr<nsIStyleContext> scrolledContentStyle;
+    nsRefPtr<nsStyleContext> scrolledContentStyle;
 
     
-    BeginBuildingScrollFrame(aPresShell, aPresContext,
-                     aState,
-                     aContent,
-                     aContentStyle,
-                     aParentFrame,
-                     nsCSSAnonBoxes::scrolledContent,
-                     mDocument,
-                     PR_FALSE,
-                     aNewFrame,
-                     scrolledContentStyle,
-                     scrollFrame,
-                     aScrollPortFrame);
+    scrolledContentStyle = BeginBuildingScrollFrame(aPresShell, aPresContext,
+                                                    aState,
+                                                    aContent,
+                                                    aContentStyle,
+                                                    aParentFrame,
+                                                    nsCSSAnonBoxes::scrolledContent,
+                                                    mDocument,
+                                                    PR_FALSE,
+                                                    aNewFrame,
+                                                    scrollFrame,
+                                                    aScrollPortFrame);
     
     InitAndRestoreFrame(aPresContext, aState, aContent, 
                         scrollFrame, scrolledContentStyle, nsnull, aScrolledFrame);
@@ -6287,7 +6257,7 @@ nsCSSFrameConstructor::BuildGfxScrollFrame (nsIPresShell* aPresShell,
                                              nsIContent*              aContent,
                                              nsIDocument*             aDocument,
                                              nsIFrame*                aParentFrame,
-                                             nsIStyleContext*         aStyleContext,
+                                             nsStyleContext*          aStyleContext,
                                              PRBool                   aIsRoot,
                                              nsIFrame*&               aNewFrame,
                                              nsFrameItems&            aAnonymousFrames,
@@ -6327,7 +6297,7 @@ nsCSSFrameConstructor::ConstructFrameByDisplayType(nsIPresShell*            aPre
                                                    PRInt32                  aNameSpaceID,
                                                    nsIAtom*                 aTag,
                                                    nsIFrame*                aParentFrame,
-                                                   nsIStyleContext*         aStyleContext,
+                                                   nsStyleContext*          aStyleContext,
                                                    nsFrameItems&            aFrameItems)
 {
   PRBool    primaryFrameSet = PR_FALSE;
@@ -6405,7 +6375,7 @@ nsCSSFrameConstructor::ConstructFrameByDisplayType(nsIPresShell*            aPre
                     NS_BLOCK_SHRINK_WRAP | NS_BLOCK_MARGIN_ROOT);
 
 
-    nsIStyleContext* newStyle = nsnull;
+    nsStyleContext* newStyle;
     // Build the scrollframe it
     BuildScrollFrame(aPresShell, aPresContext, aState, aContent, aStyleContext, scrolledFrame, geometricParent,
                      newFrame, newStyle);
@@ -6444,7 +6414,7 @@ nsCSSFrameConstructor::ConstructFrameByDisplayType(nsIPresShell*            aPre
     CreateAnonymousFrames(aPresShell, aPresContext, tag, aState, aContent, newFrame,
                             childItems);
 
-      // Set the scrolled frame's initial child lists
+    // Set the scrolled frame's initial child lists
     scrolledFrame->SetInitialChildList(aPresContext, nsnull, childItems.childList);
     if (isPositionedContainingBlock && aState.mAbsoluteItems.childList) {
       scrolledFrame->SetInitialChildList(aPresContext,
@@ -6847,7 +6817,7 @@ nsCSSFrameConstructor::InitAndRestoreFrame(nsIPresContext*          aPresContext
                                            nsFrameConstructorState& aState,
                                            nsIContent*              aContent,
                                            nsIFrame*                aParentFrame,
-                                           nsIStyleContext*         aStyleContext,
+                                           nsStyleContext*          aStyleContext,
                                            nsIFrame*                aPrevInFlow,
                                            nsIFrame*                aNewFrame)
 {
@@ -6870,21 +6840,16 @@ nsCSSFrameConstructor::InitAndRestoreFrame(nsIPresContext*          aPresContext
   return rv;
 }
 
-nsresult
+already_AddRefed<nsStyleContext>
 nsCSSFrameConstructor::ResolveStyleContext(nsIPresContext*   aPresContext,
                                            nsIFrame*         aParentFrame,
-                                           nsIContent*       aContent,
-                                           nsIStyleContext** aStyleContext)
+                                           nsIContent*       aContent)
 {
-  nsresult rv = NS_OK;
   // Resolve the style context based on the content object and the parent
   // style context
-  nsCOMPtr<nsIStyleContext> parentStyleContext;
-
-  aParentFrame->GetStyleContext(getter_AddRefs(parentStyleContext));
+  nsStyleContext* parentStyleContext = aParentFrame->GetStyleContext();
   if (aContent->IsContentOfType(nsIContent::eELEMENT)) {
-    rv = aPresContext->ResolveStyleContextFor(aContent, parentStyleContext,
-                                              aStyleContext);
+    return aPresContext->ResolveStyleContextFor(aContent, parentStyleContext);
   } else {
 #ifdef DEBUG
     {
@@ -6895,10 +6860,8 @@ nsCSSFrameConstructor::ResolveStyleContext(nsIPresContext*   aPresContext,
                    "comments and processing instructions");
     }
 #endif
-    rv = aPresContext->ResolveStyleContextForNonElement(parentStyleContext,
-                                                        aStyleContext);
+    return aPresContext->ResolveStyleContextForNonElement(parentStyleContext);
   }
-  return rv;
 }
 
 // MathML Mod - RBS
@@ -6911,7 +6874,7 @@ nsCSSFrameConstructor::ConstructMathMLFrame(nsIPresShell*            aPresShell,
                                             nsIFrame*                aParentFrame,
                                             nsIAtom*                 aTag,
                                             PRInt32                  aNameSpaceID,
-                                            nsIStyleContext*         aStyleContext,
+                                            nsStyleContext*          aStyleContext,
                                             nsFrameItems&            aFrameItems)
 {
   // Make sure that we remain confined in the MathML world
@@ -6951,104 +6914,101 @@ nsCSSFrameConstructor::ConstructMathMLFrame(nsIPresShell*            aPresShell,
       aTag == nsMathMLAtoms::mn_ ||
       aTag == nsMathMLAtoms::ms_ ||
       aTag == nsMathMLAtoms::mtext_)
-     rv = NS_NewMathMLTokenFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLTokenFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mo_)
-     rv = NS_NewMathMLmoFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmoFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mfrac_)
-     rv = NS_NewMathMLmfracFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmfracFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::msup_)
-     rv = NS_NewMathMLmsupFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmsupFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::msub_)
-     rv = NS_NewMathMLmsubFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmsubFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::msubsup_)
-     rv = NS_NewMathMLmsubsupFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmsubsupFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::munder_)
-     rv = NS_NewMathMLmunderFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmunderFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mover_)
-     rv = NS_NewMathMLmoverFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmoverFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::munderover_)
-     rv = NS_NewMathMLmunderoverFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmunderoverFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mphantom_)
-     rv = NS_NewMathMLmphantomFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmphantomFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mpadded_)
-     rv = NS_NewMathMLmpaddedFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmpaddedFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mspace_)
-     rv = NS_NewMathMLmspaceFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmspaceFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mfenced_)
-     rv = NS_NewMathMLmfencedFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmfencedFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mmultiscripts_)
-     rv = NS_NewMathMLmmultiscriptsFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmmultiscriptsFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mstyle_)
-     rv = NS_NewMathMLmstyleFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmstyleFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::msqrt_)
-     rv = NS_NewMathMLmsqrtFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmsqrtFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mroot_)
-     rv = NS_NewMathMLmrootFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmrootFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::maction_)
-     rv = NS_NewMathMLmactionFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmactionFrame(aPresShell, &newFrame);
   else if (aTag == nsMathMLAtoms::mrow_   ||
            aTag == nsMathMLAtoms::merror_ ||
            aTag == nsMathMLAtoms::none_   ||
            aTag == nsMathMLAtoms::mprescripts_ )
-     rv = NS_NewMathMLmrowFrame(aPresShell, &newFrame);
+    rv = NS_NewMathMLmrowFrame(aPresShell, &newFrame);
   // CONSTRUCTION of MTABLE elements
   else if (aTag == nsMathMLAtoms::mtable_ &&
            disp->mDisplay == NS_STYLE_DISPLAY_TABLE) {
-      // <mtable> is an inline-table -- but this isn't yet supported.
-      // What we do here is to wrap the table in an anonymous containing
-      // block so that it can mix better with other surrounding MathML markups
+    // <mtable> is an inline-table -- but this isn't yet supported.
+    // What we do here is to wrap the table in an anonymous containing
+    // block so that it can mix better with other surrounding MathML markups
 
-      nsCOMPtr<nsIStyleContext> parentContext;
-      aParentFrame->GetStyleContext(getter_AddRefs(parentContext));
+    nsStyleContext* parentContext = aParentFrame->GetStyleContext();
 
-      // first, create a MathML mrow frame that will wrap the block frame
-      rv = NS_NewMathMLmrowFrame(aPresShell, &newFrame);
-      if (NS_FAILED(rv)) return rv;
-      nsCOMPtr<nsIStyleContext> mrowContext;
-      aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                                 nsMathMLAtoms::mozMathInline,
-                                                 parentContext,
-                                                 getter_AddRefs(mrowContext));
-      InitAndRestoreFrame(aPresContext, aState, aContent, aParentFrame,
-                          mrowContext, nsnull, newFrame);
+    // first, create a MathML mrow frame that will wrap the block frame
+    rv = NS_NewMathMLmrowFrame(aPresShell, &newFrame);
+    if (NS_FAILED(rv)) return rv;
+    nsRefPtr<nsStyleContext> mrowContext;
+    mrowContext = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                             nsMathMLAtoms::mozMathInline,
+                                                             parentContext);
+    InitAndRestoreFrame(aPresContext, aState, aContent, aParentFrame,
+                        mrowContext, nsnull, newFrame);
 
-      // then, create a block frame that will wrap the table frame
-      nsIFrame* blockFrame;
-      rv = NS_NewBlockFrame(aPresShell, &blockFrame);
-      if (NS_FAILED(rv)) return rv;
-      nsCOMPtr<nsIStyleContext> blockContext;
-      aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                                 nsCSSAnonBoxes::mozAnonymousBlock,
-                                                 mrowContext,
-                                                 getter_AddRefs(blockContext));
-      InitAndRestoreFrame(aPresContext, aState, aContent, newFrame,
-                          blockContext, nsnull, blockFrame);
+    // then, create a block frame that will wrap the table frame
+    nsIFrame* blockFrame;
+    rv = NS_NewBlockFrame(aPresShell, &blockFrame);
+    if (NS_FAILED(rv)) return rv;
+    nsRefPtr<nsStyleContext> blockContext;
+    blockContext = aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                              nsCSSAnonBoxes::mozAnonymousBlock,
+                                                              mrowContext);
+    InitAndRestoreFrame(aPresContext, aState, aContent, newFrame,
+                        blockContext, nsnull, blockFrame);
 
-      // then, create the table frame itself
-      nsCOMPtr<nsIStyleContext> tableContext;
-      aPresContext->ResolveStyleContextFor(aContent, blockContext,
-                                           getter_AddRefs(tableContext));
-      nsFrameItems tempItems;
-      nsIFrame* outerTable;
-      nsIFrame* innerTable;
-      PRBool pseudoParent;
-      nsMathMLmtableCreator mathTableCreator(aPresShell);
-      rv = ConstructTableFrame(aPresShell, aPresContext, aState, aContent, 
-                               blockFrame, tableContext, mathTableCreator,
-                               PR_FALSE, tempItems, outerTable, innerTable, pseudoParent);
-      // Note: table construction function takes care of initializing the frame,
-      // processing children, and setting the initial child list
+    // then, create the table frame itself
+    nsRefPtr<nsStyleContext> tableContext;
+    tableContext = aPresContext->ResolveStyleContextFor(aContent,
+                                                        blockContext);
+    nsFrameItems tempItems;
+    nsIFrame* outerTable;
+    nsIFrame* innerTable;
+    PRBool pseudoParent;
+    nsMathMLmtableCreator mathTableCreator(aPresShell);
+    rv = ConstructTableFrame(aPresShell, aPresContext, aState, aContent, 
+                             blockFrame, tableContext, mathTableCreator,
+                             PR_FALSE, tempItems, outerTable, innerTable, pseudoParent);
+    // Note: table construction function takes care of initializing the frame,
+    // processing children, and setting the initial child list
 
-      // set the outerTable as the initial child of the anonymous block
-      blockFrame->SetInitialChildList(aPresContext, nsnull, outerTable);
+    // set the outerTable as the initial child of the anonymous block
+    blockFrame->SetInitialChildList(aPresContext, nsnull, outerTable);
 
-      // set the block frame as the initial child of the mrow frame
-      newFrame->SetInitialChildList(aPresContext, nsnull, blockFrame);
+    // set the block frame as the initial child of the mrow frame
+    newFrame->SetInitialChildList(aPresContext, nsnull, blockFrame);
 
-      // add the new frame to the flow
-      aFrameItems.AddChild(newFrame);
+    // add the new frame to the flow
+    aFrameItems.AddChild(newFrame);
 
-      return rv; 
+    return rv; 
   }
   // End CONSTRUCTION of MTABLE elements 
 
@@ -7060,7 +7020,7 @@ nsCSSFrameConstructor::ConstructMathMLFrame(nsIPresShell*            aPresShell,
     rv = NS_NewMathMLmathFrame(aPresShell, &newFrame, isBlock);
   }
   else {
-     return rv;
+    return rv;
   }
 
   // If we succeeded in creating a frame then initialize it, process its
@@ -7137,7 +7097,7 @@ nsCSSFrameConstructor::ConstructSVGFrame(nsIPresShell*            aPresShell,
                                           nsIFrame*                aParentFrame,
                                           nsIAtom*                 aTag,
                                           PRInt32                  aNameSpaceID,
-                                          nsIStyleContext*         aStyleContext,
+                                          nsStyleContext*          aStyleContext,
                                           nsFrameItems&            aFrameItems)
 {
   NS_ASSERTION(NS_SUCCEEDED(aContent->GetNameSpaceID(aNameSpaceID)) && 
@@ -7273,7 +7233,7 @@ nsCSSFrameConstructor::PageBreakBefore(nsIPresShell*            aPresShell,
                                        nsFrameConstructorState& aState,
                                        nsIContent*              aContent,
                                        nsIFrame*                aParentFrame,
-                                       nsIStyleContext*         aStyleContext,
+                                       nsStyleContext*          aStyleContext,
                                        nsFrameItems&            aFrameItems)
 {
   const nsStyleDisplay* display = (const nsStyleDisplay*)
@@ -7298,14 +7258,13 @@ nsCSSFrameConstructor::ConstructPageBreakFrame(nsIPresShell*            aPresShe
                                                nsFrameConstructorState& aState,
                                                nsIContent*              aContent,
                                                nsIFrame*                aParentFrame,
-                                               nsIStyleContext*         aStyleContext,
+                                               nsStyleContext*          aStyleContext,
                                                nsFrameItems&            aFrameItems)
 {
-  nsCOMPtr<nsIStyleContext> pseudoStyle;
-  aPresContext->ResolvePseudoStyleContextFor(nsnull,
-                                             nsCSSAnonBoxes::pageBreak,
-                                             aStyleContext,
-                                             getter_AddRefs(pseudoStyle));
+  nsRefPtr<nsStyleContext> pseudoStyle;
+  pseudoStyle = aPresContext->ResolvePseudoStyleContextFor(nsnull,
+                                                           nsCSSAnonBoxes::pageBreak,
+                                                           aStyleContext);
   nsIFrame* pageBreakFrame;
   nsresult rv = NS_NewPageBreakFrame(aPresShell, &pageBreakFrame); 
   if (NS_SUCCEEDED(rv)) {
@@ -7343,31 +7302,28 @@ nsCSSFrameConstructor::ConstructFrame(nsIPresShell*            aPresShell,
       tag == nsLayoutAtoms::processingInstructionTagName)
     return rv;
 
-  nsCOMPtr<nsIStyleContext> styleContext;
-  rv = ResolveStyleContext(aPresContext, aParentFrame, aContent,
-                           getter_AddRefs(styleContext));
+  nsRefPtr<nsStyleContext> styleContext;
+  styleContext = ResolveStyleContext(aPresContext, aParentFrame, aContent);
 
-  if (NS_SUCCEEDED(rv)) {   
-    PRInt32 nameSpaceID;
-    aContent->GetNameSpaceID(nameSpaceID);
+  PRInt32 nameSpaceID;
+  aContent->GetNameSpaceID(nameSpaceID);
 
-    PRBool pageBreakAfter = PR_FALSE;
-    PRBool paginated;
-    aPresContext->IsPaginated(&paginated);
+  PRBool pageBreakAfter = PR_FALSE;
+  PRBool paginated;
+  aPresContext->IsPaginated(&paginated);
 
-    if (paginated) {
-      // See if there is a page break before, if so construct one. Also see if there is one after
-      pageBreakAfter = PageBreakBefore(aPresShell, aPresContext, aState, aContent, 
-                                       aParentFrame, styleContext, aFrameItems);
-    }
-    // construct the frame
-    rv = ConstructFrameInternal(aPresShell, aPresContext, aState, aContent, aParentFrame,
-                                tag, nameSpaceID, styleContext, aFrameItems, PR_FALSE);
-    if (NS_SUCCEEDED(rv) && pageBreakAfter) {
-      // Construct the page break after
-      ConstructPageBreakFrame(aPresShell, aPresContext, aState, aContent,
-                              aParentFrame, styleContext, aFrameItems);
-    }
+  if (paginated) {
+    // See if there is a page break before, if so construct one. Also see if there is one after
+    pageBreakAfter = PageBreakBefore(aPresShell, aPresContext, aState, aContent, 
+                                     aParentFrame, styleContext, aFrameItems);
+  }
+  // construct the frame
+  rv = ConstructFrameInternal(aPresShell, aPresContext, aState, aContent, aParentFrame,
+                              tag, nameSpaceID, styleContext, aFrameItems, PR_FALSE);
+  if (NS_SUCCEEDED(rv) && pageBreakAfter) {
+    // Construct the page break after
+    ConstructPageBreakFrame(aPresShell, aPresContext, aState, aContent,
+                            aParentFrame, styleContext, aFrameItems);
   }
   
   return rv;
@@ -7382,7 +7338,7 @@ nsCSSFrameConstructor::ConstructFrameInternal( nsIPresShell*            aPresShe
                                                nsIFrame*                aParentFrame,
                                                nsIAtom*                 aTag,
                                                PRInt32                  aNameSpaceID,
-                                               nsIStyleContext*         aStyleContext,
+                                               nsStyleContext*          aStyleContext,
                                                nsFrameItems&            aFrameItems,
                                                PRBool                   aXBLBaseTag)
 {
@@ -7391,7 +7347,7 @@ nsCSSFrameConstructor::ConstructFrameInternal( nsIPresShell*            aPresShe
   // can then be extended arbitrarily.
   const nsStyleDisplay*  display = (const nsStyleDisplay*)
         aStyleContext->GetStyleData(eStyleStruct_Display);
-  nsCOMPtr<nsIStyleContext> styleContext(aStyleContext);
+  nsRefPtr<nsStyleContext> styleContext(aStyleContext);
   nsCOMPtr<nsIXBLBinding> binding;
   if (!aXBLBaseTag)
   {
@@ -7409,10 +7365,8 @@ nsCSSFrameConstructor::ConstructFrameInternal( nsIPresShell*            aPresShe
         return NS_OK;
 
       if (resolveStyle) {
-        rv = ResolveStyleContext(aPresContext, aParentFrame, aContent,
-                                 getter_AddRefs(styleContext));
-        if (NS_FAILED(rv))
-          return rv;
+        styleContext = ResolveStyleContext(aPresContext, aParentFrame,
+                                           aContent);
       }
 
       nsCOMPtr<nsIAtom> baseTag;
@@ -7460,7 +7414,7 @@ nsCSSFrameConstructor::ConstructFrameInternal( nsIPresShell*            aPresShe
   // do it now, when constructing frames.  See bug 115291.
   {
     const nsStyleVisibility *vis;
-    GetStyleData(styleContext.get(), &vis);
+    GetStyleData(styleContext, &vis);
   }
 
   nsIFrame* lastChild = aFrameItems.lastChild;
@@ -7623,9 +7577,8 @@ nsCSSFrameConstructor::ReconstructDocElementHierarchy(nsIPresContext* aPresConte
             if (NS_SUCCEEDED(rv)) {
               // Create the new document element hierarchy
               nsIFrame*                 newChild;
-              nsCOMPtr<nsIStyleContext> rootPseudoStyle;
+              nsStyleContext* rootPseudoStyle = docParentFrame->GetStyleContext();
           
-              docParentFrame->GetStyleContext(getter_AddRefs(rootPseudoStyle));
               rv = ConstructDocElementFrame(shell, aPresContext, state, rootContent,
                                             docParentFrame, rootPseudoStyle,
                                             newChild);
@@ -7831,22 +7784,17 @@ IsGeneratedContentFor(nsIContent* aContent, nsIFrame* aFrame, nsIAtom* aPseudoEl
   // First check the frame state bit
   aFrame->GetFrameState(&state);
   if (state & NS_FRAME_GENERATED_CONTENT) {
-    nsIContent* content;
+    nsCOMPtr<nsIContent> content;
 
     // Check that it has the same content pointer
-    aFrame->GetContent(&content);
+    aFrame->GetContent(getter_AddRefs(content));
     if (content == aContent) {
-      nsIStyleContext* styleContext;
-      nsIAtom*         pseudoType;
+      nsStyleContext* styleContext = aFrame->GetStyleContext();
 
       // See if the pseudo element type matches
-      aFrame->GetStyleContext(&styleContext);
-      styleContext->GetPseudoType(pseudoType);
+      nsCOMPtr<nsIAtom> pseudoType = styleContext->GetPseudoType();
       result = (pseudoType == aPseudoElement);
-      NS_RELEASE(styleContext);
-      NS_IF_RELEASE(pseudoType);
     }
-    NS_IF_RELEASE(content);
   }
 
   return result;
@@ -8117,8 +8065,8 @@ nsCSSFrameConstructor::IsValidSibling(nsIPresShell&          aPresShell,
 
       nsIFrame* parent;
       aSibling.GetParent(&parent);
-      nsCOMPtr<nsIStyleContext> styleContext;
-      ResolveStyleContext(context, parent, &aContent, getter_AddRefs(styleContext));
+      nsRefPtr<nsStyleContext> styleContext;
+      styleContext = ResolveStyleContext(context, parent, &aContent);
       if (!styleContext) return PR_FALSE;
       const nsStyleDisplay* display = 
         (const nsStyleDisplay*) styleContext->GetStyleData(eStyleStruct_Display);
@@ -8534,8 +8482,8 @@ nsCSSFrameConstructor::ContentAppended(nsIPresContext* aPresContext,
       aContainer->ChildAt(aNewIndexInContainer, *getter_AddRefs(child));
       PRBool needReframe = !child;
       if (child && child->IsContentOfType(nsIContent::eELEMENT)) {
-        nsCOMPtr<nsIStyleContext> styleContext;
-        ResolveStyleContext(aPresContext, parentFrame, child, getter_AddRefs(styleContext)); 
+        nsRefPtr<nsStyleContext> styleContext;
+        styleContext = ResolveStyleContext(aPresContext, parentFrame, child);
         const nsStyleDisplay* display = 
           (const nsStyleDisplay*) styleContext->GetStyleData(eStyleStruct_Display);  
         // XXX since the block child goes in the last inline of the sacred triad, frames would 
@@ -8573,8 +8521,7 @@ nsCSSFrameConstructor::ContentAppended(nsIPresContext* aPresContext,
   PRBool haveFirstLetterStyle, haveFirstLineStyle;
   nsIFrame* containingBlock = state.mFloatedItems.containingBlock;
   nsCOMPtr<nsIContent> blockContent;
-  nsCOMPtr<nsIStyleContext> blockSC;
-  containingBlock->GetStyleContext(getter_AddRefs(blockSC));
+  nsStyleContext* blockSC = containingBlock->GetStyleContext();
   containingBlock->GetContent(getter_AddRefs(blockContent));
   HaveSpecialBlockStyle(aPresContext, blockContent, blockSC,
                         &haveFirstLetterStyle,
@@ -8789,9 +8736,8 @@ nsCSSFrameConstructor::AddDummyFrameToSelect(nsIPresContext*  aPresContext,
       listFrame->GetDummyFrame(&dummyFrame);
 
       if (!dummyFrame) {
-        nsCOMPtr<nsIStyleContext> styleContext;
+        nsStyleContext* styleContext = aParentFrame->GetStyleContext();
         nsIFrame*         generatedFrame = nsnull;
-        aParentFrame->GetStyleContext(getter_AddRefs(styleContext));
         if (CreateGeneratedContentFrame(aPresShell, aPresContext, aState,
                                         aParentFrame, aContainer,
                                         styleContext,
@@ -8894,8 +8840,8 @@ nsCSSFrameConstructor::NeedSpecialFrameReframe(nsIPresShell*   aPresShell,
   // find out if aChild is a block or inline
   PRBool childIsBlock = PR_FALSE;
   if (aChild->IsContentOfType(nsIContent::eELEMENT)) {
-    nsCOMPtr<nsIStyleContext> styleContext;
-    ResolveStyleContext(aPresContext, aParentFrame, aChild, getter_AddRefs(styleContext)); 
+    nsRefPtr<nsStyleContext> styleContext;
+    styleContext = ResolveStyleContext(aPresContext, aParentFrame, aChild);
     const nsStyleDisplay* display = 
       (const nsStyleDisplay*) styleContext->GetStyleData(eStyleStruct_Display);  
     childIsBlock = display->IsBlockLevel();
@@ -9060,8 +9006,7 @@ nsCSSFrameConstructor::ContentInserted(nsIPresContext*        aPresContext,
                       // InitialReflow.
 
       // Get the style context of the containing block frame
-      nsCOMPtr<nsIStyleContext> containerStyle;
-      mDocElementContainingBlock->GetStyleContext(getter_AddRefs(containerStyle));
+      nsStyleContext* containerStyle = mDocElementContainingBlock->GetStyleContext();
     
       // Create frames for the document element and its child elements
       nsIFrame*               docElementFrame;
@@ -9211,7 +9156,7 @@ nsCSSFrameConstructor::ContentInserted(nsIPresContext*        aPresContext,
   // is not the normal structure and requires custom updating
   // logic.
   nsIFrame* containingBlock = state.mFloatedItems.containingBlock;
-  nsCOMPtr<nsIStyleContext> blockSC;
+  nsStyleContext* blockSC;
   nsCOMPtr<nsIContent> blockContent;
   PRBool haveFirstLetterStyle = PR_FALSE;
   PRBool haveFirstLineStyle = PR_FALSE;
@@ -9232,7 +9177,7 @@ nsCSSFrameConstructor::ContentInserted(nsIPresContext*        aPresContext,
       (NS_STYLE_DISPLAY_INLINE == parentDisplay->mDisplay) ||
       (NS_STYLE_DISPLAY_INLINE_BLOCK == parentDisplay->mDisplay)) {
     // Recover the special style flags for the containing block
-    containingBlock->GetStyleContext(getter_AddRefs(blockSC));
+    blockSC = containingBlock->GetStyleContext();
     containingBlock->GetContent(getter_AddRefs(blockContent));
     HaveSpecialBlockStyle(aPresContext, blockContent, blockSC,
                           &haveFirstLetterStyle,
@@ -9663,15 +9608,14 @@ nsCSSFrameConstructor::RemoveMappingsForFrameSubtree(nsIPresContext* aPresContex
 static PRBool
 HasPseudoStyle(nsIPresContext* aPresContext,
                nsIContent* aContent,
-               nsIStyleContext* aStyleContext,
+               nsStyleContext* aStyleContext,
                nsIAtom* aPseudoElement)
 {
-  nsCOMPtr<nsIStyleContext> pseudoStyleContext;
+  nsRefPtr<nsStyleContext> pseudoStyleContext;
   if (aContent) {
-    aPresContext->ProbePseudoStyleContextFor(aContent,
-                                             aPseudoElement,
-                                             aStyleContext,
-                                             getter_AddRefs(pseudoStyleContext));
+    pseudoStyleContext = aPresContext->ProbePseudoStyleContextFor(aContent,
+                                                                  aPseudoElement,
+                                                                  aStyleContext);
   }
   return pseudoStyleContext != nsnull;
 }
@@ -9833,8 +9777,7 @@ nsCSSFrameConstructor::ContentRemoved(nsIPresContext* aPresContext,
     // :first-letter style applies.
     nsIFrame* containingBlock =
       GetFloaterContainingBlock(aPresContext, parentFrame);
-    nsCOMPtr<nsIStyleContext> blockSC;
-    containingBlock->GetStyleContext(getter_AddRefs(blockSC));
+    nsStyleContext* blockSC = containingBlock->GetStyleContext();
     nsCOMPtr<nsIContent> blockContent;
     containingBlock->GetContent(getter_AddRefs(blockContent));
     PRBool haveFLS = HaveFirstLetterStyle(aPresContext, blockContent, blockSC);
@@ -10322,8 +10265,7 @@ nsCSSFrameConstructor::ContentChanged(nsIPresContext* aPresContext,
         // See if the block has first-letter style applied to it.
         nsCOMPtr<nsIContent> blockContent;
         block->GetContent(getter_AddRefs(blockContent));
-        nsCOMPtr<nsIStyleContext> blockSC;
-        block->GetStyleContext(getter_AddRefs(blockSC));
+        nsStyleContext* blockSC = block->GetStyleContext();
         PRBool haveFirstLetterStyle =
           HaveFirstLetterStyle(aPresContext, blockContent, blockSC);
         if (haveFirstLetterStyle) {
@@ -10701,7 +10643,7 @@ nsCSSFrameConstructor::AttributeChanged(nsIPresContext* aPresContext,
   // check for inline style.  we need to clear the data at the style
   // context's rule node whenever the inline style property changes.
 
-  nsCOMPtr<nsIStyleContext> styleContext;
+  nsStyleContext* styleContext;
   nsCOMPtr<nsIStyleRule> rule;
   PRBool inlineStyle = PR_FALSE;
   if (aAttribute == nsHTMLAtoms::style) {
@@ -10712,13 +10654,14 @@ nsCSSFrameConstructor::AttributeChanged(nsIPresContext* aPresContext,
 
       // This style rule exists and we need to blow away any computed
       // data that this rule cached in the rule tree.
-      if (primaryStyleFrame)
-        primaryStyleFrame->GetStyleContext(getter_AddRefs(styleContext));
-      else {
+      if (primaryStyleFrame) {
+        styleContext = primaryStyleFrame->GetStyleContext();
+        styleContext->AddRef();
+      } else {
         // We might be in the undisplayed map.  Retrieve the style context from there.
         nsCOMPtr<nsIFrameManager> frameManager;
         shell->GetFrameManager(getter_AddRefs(frameManager));
-        frameManager->GetUndisplayedContent(aContent, getter_AddRefs(styleContext));
+        styleContext = frameManager->GetUndisplayedContent(aContent);
 #ifdef DEBUG
         if (!styleContext) {
           nsCOMPtr<nsIContent> parent;
@@ -10733,6 +10676,8 @@ nsCSSFrameConstructor::AttributeChanged(nsIPresContext* aPresContext,
 #endif
       }
     }
+    if (styleContext)
+      styleContext->Release();
   }
 
   // first see if we need to manage the style system: 
@@ -10937,7 +10882,7 @@ nsresult
 nsCSSFrameConstructor::ConstructAlternateFrame(nsIPresShell*    aPresShell, 
                                                nsIPresContext*  aPresContext,
                                                nsIContent*      aContent,
-                                               nsIStyleContext* aStyleContext,
+                                               nsStyleContext*  aStyleContext,
                                                nsIFrame*        aParentFrame,
                                                nsIFrame*&       aFrame)
 {
@@ -10997,15 +10942,13 @@ nsCSSFrameConstructor::ConstructAlternateFrame(nsIPresShell*    aPresShell,
   // Create a text frame to display the alt-text. It gets a pseudo-element
   // style context
   nsIFrame*        textFrame;
-  nsIStyleContext* textStyleContext;
-
   NS_NewTextFrame(aPresShell, &textFrame);
-  aPresContext->ResolveStyleContextForNonElement(aStyleContext,
-                                                 &textStyleContext);
+
+  nsRefPtr<nsStyleContext> textStyleContext;
+  textStyleContext = aPresContext->ResolveStyleContextForNonElement(aStyleContext);
 
   textFrame->Init(aPresContext, altTextContent, containerFrame,
                   textStyleContext, nsnull);
-  NS_RELEASE(textStyleContext);
   containerFrame->SetInitialChildList(aPresContext, nsnull, textFrame);
 
   // Return the container frame
@@ -11086,9 +11029,8 @@ nsCSSFrameConstructor::CantRenderReplacedElement(nsIPresShell* aPresShell,
 
   // Get parent frame and style context
   nsIFrame*                 parentFrame;
-  nsCOMPtr<nsIStyleContext> styleContext;
   aFrame->GetParent(&parentFrame);
-  aFrame->GetStyleContext(getter_AddRefs(styleContext));
+  nsStyleContext* styleContext = aFrame->GetStyleContext();
 
   // Get aFrame's content object and the tag name
   nsCOMPtr<nsIContent>      content;
@@ -11338,7 +11280,7 @@ nsCSSFrameConstructor::CreateContinuingOuterTableFrame(nsIPresShell* aPresShell,
                                                        nsIFrame*        aFrame,
                                                        nsIFrame*        aParentFrame,
                                                        nsIContent*      aContent,
-                                                       nsIStyleContext* aStyleContext,
+                                                       nsStyleContext*  aStyleContext,
                                                        nsIFrame**       aContinuingFrame)
 {
   nsIFrame* newFrame;
@@ -11372,11 +11314,10 @@ nsCSSFrameConstructor::CreateContinuingOuterTableFrame(nsIPresShell* aPresShell,
         // the caption (that is what the thead is for). This code is not executed 
         // anyway, because the caption was put in a different child list.
         nsIContent*           caption;
-        nsIStyleContext*      captionStyle;
+        nsStyleContext*       captionStyle = childFrame->GetStyleContext();
         const nsStyleDisplay* display;
 
         childFrame->GetContent(&caption);
-        childFrame->GetStyleContext(&captionStyle);
         display = (const nsStyleDisplay*)captionStyle->GetStyleData(eStyleStruct_Display);
         NS_ASSERTION(NS_STYLE_DISPLAY_TABLE_CAPTION == display->mDisplay, "expected caption");
 
@@ -11402,7 +11343,6 @@ nsCSSFrameConstructor::CreateContinuingOuterTableFrame(nsIPresShell* aPresShell,
         }
         newChildFrames.AddChild(captionFrame);
         NS_RELEASE(caption);
-        NS_RELEASE(captionStyle);
       }
       NS_IF_RELEASE(tableType);
       childFrame->GetNextSibling(&childFrame);
@@ -11422,7 +11362,7 @@ nsCSSFrameConstructor::CreateContinuingTableFrame(nsIPresShell* aPresShell,
                                                   nsIFrame*        aFrame,
                                                   nsIFrame*        aParentFrame,
                                                   nsIContent*      aContent,
-                                                  nsIStyleContext* aStyleContext,
+                                                  nsStyleContext*  aStyleContext,
                                                   nsIFrame**       aContinuingFrame)
 {
   nsIFrame* newFrame;
@@ -11441,10 +11381,9 @@ nsCSSFrameConstructor::CreateContinuingTableFrame(nsIPresShell* aPresShell,
     aFrame->FirstChild(aPresContext, nsnull, &rowGroupFrame);
     while (rowGroupFrame) {
       // See if it's a header/footer
-      nsIStyleContext*      rowGroupStyle;
+      nsStyleContext*       rowGroupStyle = rowGroupFrame->GetStyleContext();
       const nsStyleDisplay* display;
 
-      rowGroupFrame->GetStyleContext(&rowGroupStyle);
       display = (const nsStyleDisplay*)rowGroupStyle->GetStyleData(eStyleStruct_Display);
 
       if ((NS_STYLE_DISPLAY_TABLE_HEADER_GROUP == display->mDisplay) ||
@@ -11485,8 +11424,6 @@ nsCSSFrameConstructor::CreateContinuingTableFrame(nsIPresShell* aPresShell,
         }
       }
 
-      NS_RELEASE(rowGroupStyle);
-      
       // Get the next row group frame
       rowGroupFrame->GetNextSibling(&rowGroupFrame);
     }
@@ -11508,14 +11445,13 @@ nsCSSFrameConstructor::CreateContinuingFrame(nsIPresShell*   aPresShell,
 {
   nsCOMPtr<nsIAtom>          frameType;
   nsCOMPtr<nsIContent>       content;
-  nsCOMPtr<nsIStyleContext>  styleContext;
+  nsStyleContext*            styleContext = aFrame->GetStyleContext();
   nsIFrame*                  newFrame = nsnull;
   nsresult                   rv = NS_OK;
 
   // Use the frame type to determine what type of frame to create
   aFrame->GetFrameType(getter_AddRefs(frameType));
   aFrame->GetContent(getter_AddRefs(content));
-  aFrame->GetStyleContext(getter_AddRefs(styleContext));
 
   if (nsLayoutAtoms::textFrame == frameType) {
     rv = NS_NewContinuingTextFrame(aPresShell, &newFrame);
@@ -11560,7 +11496,7 @@ nsCSSFrameConstructor::CreateContinuingFrame(nsIPresShell*   aPresShell,
 
   } else if (nsLayoutAtoms::pageFrame == frameType) {
     nsIFrame* pageContentFrame;
-    rv = ConstructPageFrame(aPresShell, aPresContext, aParentFrame, aFrame, 
+    rv = ConstructPageFrame(aPresShell, aPresContext, aParentFrame, aFrame,
                             newFrame, pageContentFrame);
   } else if (nsLayoutAtoms::tableOuterFrame == frameType) {
     rv = CreateContinuingOuterTableFrame(aPresShell, aPresContext, aFrame, aParentFrame,
@@ -12095,7 +12031,7 @@ nsresult
 nsCSSFrameConstructor::RecreateFramesForContent(nsIPresContext* aPresContext,
                                                 nsIContent* aContent, PRBool aInlineStyle,
                                                 nsIStyleRule* aInlineStyleRule,
-                                                nsIStyleContext* aStyleContext)                                   
+                                                nsStyleContext* aStyleContext)                                   
 {
   // Is the frame `special'? If so, we need to reframe the containing
   // block *here*, rather than trying to remove and re-insert the
@@ -12186,32 +12122,30 @@ nsCSSFrameConstructor::RecreateFramesForContent(nsIPresContext* aPresContext,
 
 // Block frame construction code
 
-nsIStyleContext*
+already_AddRefed<nsStyleContext>
 nsCSSFrameConstructor::GetFirstLetterStyle(nsIPresContext* aPresContext,
                                            nsIContent* aContent,
-                                           nsIStyleContext* aStyleContext)
+                                           nsStyleContext* aStyleContext)
 {
-  nsIStyleContext* fls = nsnull;
   if (aContent) {
-    aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                               nsCSSPseudoElements::firstLetter,
-                                               aStyleContext, &fls);
+    return aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                      nsCSSPseudoElements::firstLetter,
+                                                      aStyleContext);
   }
-  return fls;
+  return nsnull;
 }
 
-nsIStyleContext*
+already_AddRefed<nsStyleContext>
 nsCSSFrameConstructor::GetFirstLineStyle(nsIPresContext* aPresContext,
                                          nsIContent* aContent,
-                                         nsIStyleContext* aStyleContext)
+                                         nsStyleContext* aStyleContext)
 {
-  nsIStyleContext* fls = nsnull;
   if (aContent) {
-    aPresContext->ResolvePseudoStyleContextFor(aContent,
-                                               nsCSSPseudoElements::firstLine,
-                                               aStyleContext, &fls);
+    return aPresContext->ResolvePseudoStyleContextFor(aContent,
+                                                      nsCSSPseudoElements::firstLine,
+                                                      aStyleContext);
   }
-  return fls;
+  return nsnull;
 }
 
 // Predicate to see if a given content (block element) has
@@ -12219,7 +12153,7 @@ nsCSSFrameConstructor::GetFirstLineStyle(nsIPresContext* aPresContext,
 PRBool
 nsCSSFrameConstructor::HaveFirstLetterStyle(nsIPresContext* aPresContext,
                                             nsIContent* aContent,
-                                            nsIStyleContext* aStyleContext)
+                                            nsStyleContext* aStyleContext)
 {
   return HasPseudoStyle(aPresContext, aContent, aStyleContext,
                         nsCSSPseudoElements::firstLetter);
@@ -12228,7 +12162,7 @@ nsCSSFrameConstructor::HaveFirstLetterStyle(nsIPresContext* aPresContext,
 PRBool
 nsCSSFrameConstructor::HaveFirstLineStyle(nsIPresContext* aPresContext,
                                           nsIContent* aContent,
-                                          nsIStyleContext* aStyleContext)
+                                          nsStyleContext* aStyleContext)
 {
   return HasPseudoStyle(aPresContext, aContent, aStyleContext,
                         nsCSSPseudoElements::firstLine);
@@ -12237,7 +12171,7 @@ nsCSSFrameConstructor::HaveFirstLineStyle(nsIPresContext* aPresContext,
 void
 nsCSSFrameConstructor::HaveSpecialBlockStyle(nsIPresContext* aPresContext,
                                              nsIContent* aContent,
-                                             nsIStyleContext* aStyleContext,
+                                             nsStyleContext* aStyleContext,
                                              PRBool* aHaveFirstLetterStyle,
                                              PRBool* aHaveFirstLineStyle)
 {
@@ -12267,8 +12201,7 @@ nsCSSFrameConstructor::ProcessChildren(nsIPresShell*            aPresShell,
                                        nsTableCreator*          aTableCreator)
 {
   nsresult rv = NS_OK;
-  nsCOMPtr<nsIStyleContext> styleContext;
-  aFrame->GetStyleContext(getter_AddRefs(styleContext));
+  nsStyleContext* styleContext = aFrame->GetStyleContext();
     
   if (aCanHaveGeneratedContent) {
     // Probe for generated content before
@@ -12342,7 +12275,7 @@ nsCSSFrameConstructor::ProcessChildren(nsIPresShell*            aPresShell,
 static void
 ReparentFrame(nsIPresContext* aPresContext,
               nsIFrame* aNewParentFrame,
-              nsIStyleContext* aParentStyleContext,
+              nsStyleContext* aParentStyleContext,
               nsIFrame* aFrame)
 {
   aPresContext->ReParentStyleContext(aFrame, aParentStyleContext);
@@ -12384,9 +12317,8 @@ nsCSSFrameConstructor::WrapFramesInFirstLineFrame(
   }
 
   // Create line frame
-  nsCOMPtr<nsIStyleContext> parentStyle;
-  aFrame->GetStyleContext(getter_AddRefs(parentStyle));
-  nsCOMPtr<nsIStyleContext> firstLineStyle(
+  nsStyleContext* parentStyle = aFrame->GetStyleContext();
+  nsRefPtr<nsStyleContext> firstLineStyle(
     getter_AddRefs(GetFirstLineStyle(aPresContext, aContent, parentStyle))
     );
   nsIFrame* lineFrame;
@@ -12463,8 +12395,7 @@ nsCSSFrameConstructor::AppendFirstLineFrames(
     return rv;
   }
   nsIFrame* lineFrame = lastBlockKid;
-  nsCOMPtr<nsIStyleContext> firstLineStyle;
-  lineFrame->GetStyleContext(getter_AddRefs(firstLineStyle));
+  nsStyleContext* firstLineStyle = lineFrame->GetStyleContext();
 
   // Find the first and last inline frame in aFrameItems
   nsIFrame* kid = aFrameItems.childList;
@@ -12540,8 +12471,7 @@ nsCSSFrameConstructor::InsertFirstLineFrames(
     if (frameType.get() == nsLayoutAtoms::lineFrame) {
       // We already have a first-line frame
       nsIFrame* lineFrame = firstBlockKid;
-      nsCOMPtr<nsIStyleContext> firstLineStyle;
-      lineFrame->GetStyleContext(getter_AddRefs(firstLineStyle));
+      nsStyleContext* firstLineStyle = lineFrame->GetStyleContext();
 
       if (isInline) {
         // Easy case: the new inline frame will go into the lineFrame.
@@ -12569,9 +12499,8 @@ nsCSSFrameConstructor::InsertFirstLineFrames(
         rv = NS_NewFirstLineFrame(&lineFrame);
         if (NS_SUCCEEDED(rv)) {
           // Lookup first-line style context
-          nsCOMPtr<nsIStyleContext> parentStyle;
-          aBlockFrame->GetStyleContext(getter_AddRefs(parentStyle));
-          nsCOMPtr<nsIStyleContext> firstLineStyle(
+          nsStyleContext* parentStyle = aBlockFrame->GetStyleContext();
+          nsRefPtr<nsStyleContext> firstLineStyle(
             getter_AddRefs(GetFirstLineStyle(aPresContext, aContent,
                                              parentStyle))
             );
@@ -12758,7 +12687,7 @@ nsCSSFrameConstructor::CreateFloatingLetterFrame(
   nsIFrame* aTextFrame,
   nsIContent* aBlockContent,
   nsIFrame* aParentFrame,
-  nsIStyleContext* aStyleContext,
+  nsStyleContext* aStyleContext,
   nsFrameItems& aResult)
 {
   // Create the first-letter-frame
@@ -12772,9 +12701,8 @@ nsCSSFrameConstructor::CreateFloatingLetterFrame(
   // get a proper style context for it (the one passed in is for the
   // letter frame and will have the float property set on it; the text
   // frame shouldn't have that set).
-  nsCOMPtr<nsIStyleContext> textSC;
-  aPresContext->ResolveStyleContextForNonElement(aStyleContext,
-                                                 getter_AddRefs(textSC));  
+  nsRefPtr<nsStyleContext> textSC;
+  textSC = aPresContext->ResolveStyleContextForNonElement(aStyleContext);
   InitAndRestoreFrame(aPresContext, aState, aTextContent, 
                       letterFrame, textSC, nsnull, aTextFrame);
 
@@ -12798,12 +12726,10 @@ nsCSSFrameConstructor::CreateFloatingLetterFrame(
                           &nextTextFrame);
 
     // Repair the continuations style context
-    nsCOMPtr<nsIStyleContext> parentStyleContext;
-    parentStyleContext = getter_AddRefs(aStyleContext->GetParent());
+    nsStyleContext* parentStyleContext = aStyleContext->GetParent();
     if (parentStyleContext) {
-      nsCOMPtr<nsIStyleContext> newSC;
-      aPresContext->ResolveStyleContextForNonElement(parentStyleContext,
-                                                     getter_AddRefs(newSC));
+      nsRefPtr<nsStyleContext> newSC;
+      newSC = aPresContext->ResolveStyleContextForNonElement(parentStyleContext);
       if (newSC) {
         nextTextFrame->SetStyleContext(aPresContext, newSC);
       }
@@ -12836,8 +12762,7 @@ nsCSSFrameConstructor::CreateLetterFrame(nsIPresShell* aPresShell, nsIPresContex
   aParentFrame->GetContent(getter_AddRefs(parentContent));
 
   // Get style context for the first-letter-frame
-  nsCOMPtr<nsIStyleContext> parentStyleContext;
-  aParentFrame->GetStyleContext(getter_AddRefs(parentStyleContext));
+  nsStyleContext* parentStyleContext = aParentFrame->GetStyleContext();
   if (parentStyleContext) {
     // Use content from containing block so that we can actually
     // find a matching style rule.
@@ -12846,7 +12771,7 @@ nsCSSFrameConstructor::CreateLetterFrame(nsIPresShell* aPresShell, nsIPresContex
       getter_AddRefs(blockContent));
 
     // Create first-letter style rule
-    nsCOMPtr<nsIStyleContext> sc = getter_AddRefs(
+    nsRefPtr<nsStyleContext> sc = getter_AddRefs(
       GetFirstLetterStyle(aPresContext, blockContent, parentStyleContext));
     if (sc) {
       // Create a new text frame (the original one will be discarded)
@@ -12871,9 +12796,8 @@ nsCSSFrameConstructor::CreateLetterFrame(nsIPresShell* aPresShell, nsIPresContex
           // Initialize the first-letter-frame.
           letterFrame->Init(aPresContext, aTextContent, aParentFrame,
                             sc, nsnull);
-          nsCOMPtr<nsIStyleContext> textSC;
-          aPresContext->ResolveStyleContextForNonElement(sc,
-                                                       getter_AddRefs(textSC));
+          nsRefPtr<nsStyleContext> textSC;
+          textSC = aPresContext->ResolveStyleContextForNonElement(sc);
           InitAndRestoreFrame(aPresContext, aState, aTextContent, 
                               letterFrame, textSC, nsnull, textFrame);          
           letterFrame->SetInitialChildList(aPresContext, nsnull, textFrame);
@@ -13072,8 +12996,7 @@ nsCSSFrameConstructor::RemoveFloatingFirstLetterFrames(
   // Create a new text frame with the right style context that maps
   // all of the content that was previously part of the letter frame
   // (and probably continued elsewhere).
-  nsCOMPtr<nsIStyleContext> parentSC;
-  parentFrame->GetStyleContext(getter_AddRefs(parentSC));
+  nsStyleContext* parentSC = parentFrame->GetStyleContext();
   if (!parentSC) {
     return NS_OK;
   }
@@ -13082,9 +13005,8 @@ nsCSSFrameConstructor::RemoveFloatingFirstLetterFrames(
   if (!textContent) {
     return NS_OK;
   }
-  nsCOMPtr<nsIStyleContext> newSC;
-  aPresContext->ResolveStyleContextForNonElement(parentSC,
-                                                 getter_AddRefs(newSC));
+  nsRefPtr<nsStyleContext> newSC;
+  newSC = aPresContext->ResolveStyleContextForNonElement(parentSC);
   if (!newSC) {
     return NS_OK;
   }
@@ -13172,8 +13094,7 @@ nsCSSFrameConstructor::RemoveFirstLetterFrames(nsIPresContext* aPresContext,
       }
 
       // Create a new textframe
-      nsCOMPtr<nsIStyleContext> parentSC;
-      aFrame->GetStyleContext(getter_AddRefs(parentSC));
+      nsStyleContext* parentSC = aFrame->GetStyleContext();
       if (!parentSC) {
         break;
       }
@@ -13182,9 +13103,8 @@ nsCSSFrameConstructor::RemoveFirstLetterFrames(nsIPresContext* aPresContext,
       if (!textContent) {
         break;
       }
-      nsCOMPtr<nsIStyleContext> newSC;
-      aPresContext->ResolveStyleContextForNonElement(parentSC,
-                                                     getter_AddRefs(newSC));
+      nsRefPtr<nsStyleContext> newSC;
+      newSC = aPresContext->ResolveStyleContextForNonElement(parentSC);
       if (!newSC) {
         break;
       }
@@ -13307,20 +13227,17 @@ nsCSSFrameConstructor::CreateListBoxContent(nsIPresContext* aPresContext,
                                   GetFloaterContainingBlock(aPresContext, aParentFrame), 
                                   mTempFrameTreeState);
 
-    nsCOMPtr<nsIStyleContext> styleContext;
-    rv = ResolveStyleContext(aPresContext, aParentFrame, aChild,
-                             getter_AddRefs(styleContext));
+    nsRefPtr<nsStyleContext> styleContext;
+    styleContext = ResolveStyleContext(aPresContext, aParentFrame, aChild);
 
-    if (NS_SUCCEEDED(rv)) {
-      // Pre-check for display "none" - only if we find that, do we create
-      // any frame at all
-      const nsStyleDisplay* display = (const nsStyleDisplay*)
-        styleContext->GetStyleData(eStyleStruct_Display);
+    // Pre-check for display "none" - only if we find that, do we create
+    // any frame at all
+    const nsStyleDisplay* display = (const nsStyleDisplay*)
+      styleContext->GetStyleData(eStyleStruct_Display);
 
-      if (NS_STYLE_DISPLAY_NONE == display->mDisplay) {
-        *aNewFrame = nsnull;
-        return NS_OK;
-      }
+    if (NS_STYLE_DISPLAY_NONE == display->mDisplay) {
+      *aNewFrame = nsnull;
+      return NS_OK;
     }
 
     nsCOMPtr<nsIAtom> tag;
@@ -13392,7 +13309,7 @@ nsCSSFrameConstructor::ConstructBlock(nsIPresShell*            aPresShell,
                                       const nsStyleDisplay*    aDisplay,
                                       nsIContent*              aContent,
                                       nsIFrame*                aParentFrame,
-                                      nsIStyleContext*         aStyleContext,
+                                      nsStyleContext*          aStyleContext,
                                       nsIFrame*                aNewFrame,
                                       PRBool                   aRelPos)
 {
@@ -13468,12 +13385,12 @@ nsCSSFrameConstructor::ProcessBlockChildren(nsIPresShell* aPresShell,
                                             PRBool                   aParentIsBlock)
 {
   nsresult rv = NS_OK;
-  nsCOMPtr<nsIStyleContext> styleContext;
+  nsStyleContext* styleContext;
 
   if (aCanHaveGeneratedContent) {
     // Probe for generated content before
     nsIFrame* generatedFrame;
-    aFrame->GetStyleContext(getter_AddRefs(styleContext));
+    styleContext = aFrame->GetStyleContext();
     if (CreateGeneratedContentFrame(aPresShell, aPresContext, aState, aFrame, aContent,
                                     styleContext, nsCSSPseudoElements::before,
                                     nsnull, &generatedFrame)) {
@@ -13544,7 +13461,7 @@ nsCSSFrameConstructor::ConstructInline(nsIPresShell*            aPresShell,
                                        const nsStyleDisplay*    aDisplay,
                                        nsIContent*              aContent,
                                        nsIFrame*                aParentFrame,
-                                       nsIStyleContext*         aStyleContext,
+                                       nsStyleContext*          aStyleContext,
                                        PRBool                   aIsPositioned,
                                        nsIFrame*                aNewFrame,
                                        nsIFrame**               aNewBlockFrame,
@@ -13662,10 +13579,9 @@ nsCSSFrameConstructor::ConstructInline(nsIPresShell*            aPresShell,
     blockStyle = nsCSSAnonBoxes::mozAnonymousBlock;
   }
 
-  nsCOMPtr<nsIStyleContext> blockSC;
-  aPresContext->ResolvePseudoStyleContextFor(aContent, blockStyle,
-                                             aStyleContext,
-                                             getter_AddRefs(blockSC));
+  nsRefPtr<nsStyleContext> blockSC;
+  blockSC = aPresContext->ResolvePseudoStyleContextFor(aContent, blockStyle,
+                                                       aStyleContext);
 
   InitAndRestoreFrame(aPresContext, aState, aContent, 
                       aParentFrame, blockSC, nsnull, blockFrame);  
@@ -13768,7 +13684,7 @@ nsCSSFrameConstructor::ProcessInlineChildren(nsIPresShell* aPresShell,
                                              PRBool*                  aKidsAllInline)
 {
   nsresult rv = NS_OK;
-  nsCOMPtr<nsIStyleContext> styleContext;
+  nsStyleContext* styleContext;
 
   // save the pseudo frame state 
   nsPseudoFrames prevPseudoFrames; 
@@ -13777,7 +13693,7 @@ nsCSSFrameConstructor::ProcessInlineChildren(nsIPresShell* aPresShell,
   if (aCanHaveGeneratedContent) {
     // Probe for generated content before
     nsIFrame* generatedFrame;
-    aFrame->GetStyleContext(getter_AddRefs(styleContext));
+    styleContext = aFrame->GetStyleContext();
     if (CreateGeneratedContentFrame(aPresShell, aPresContext, aState, aFrame, aContent,
                                     styleContext, nsCSSPseudoElements::before,
                                     nsnull, &generatedFrame)) {
@@ -14107,8 +14023,7 @@ nsCSSFrameConstructor::SplitToContainingBlock(nsIPresContext* aPresContext,
 
       if (state & NS_FRAME_HAS_VIEW) {
         // ...create a new view for the block child, and reparent views
-        nsCOMPtr<nsIStyleContext> sc;
-        aLeftInlineChildFrame->GetStyleContext(getter_AddRefs(sc));
+        nsStyleContext* sc = aLeftInlineChildFrame->GetStyleContext();
 
         nsHTMLContainerFrame::CreateViewForFrame(aPresContext, aBlockChildFrame,
                                                  sc, nsnull, PR_FALSE);
@@ -14144,14 +14059,12 @@ nsCSSFrameConstructor::SplitToContainingBlock(nsIPresContext* aPresContext,
   if (! blockFrame)
     return NS_ERROR_OUT_OF_MEMORY;
 
-  nsCOMPtr<nsIStyleContext> styleContext;
-  aFrame->GetStyleContext(getter_AddRefs(styleContext));
+  nsStyleContext* styleContext = aFrame->GetStyleContext();
 
-  nsCOMPtr<nsIStyleContext> blockSC;
-  aPresContext->ResolvePseudoStyleContextFor(content,
-                                             nsCSSAnonBoxes::mozAnonymousBlock,
-                                             styleContext,
-                                             getter_AddRefs(blockSC));
+  nsRefPtr<nsStyleContext> blockSC;
+  blockSC = aPresContext->ResolvePseudoStyleContextFor(content,
+                                                       nsCSSAnonBoxes::mozAnonymousBlock,
+                                                       styleContext);
 
   InitAndRestoreFrame(aPresContext, aState, content,
                       nsnull, blockSC, nsnull, blockFrame);
diff --git a/mozilla/layout/html/style/src/nsCSSFrameConstructor.h b/mozilla/layout/html/style/src/nsCSSFrameConstructor.h
index a62d6aa2376..2a4642a5ffb 100644
--- a/mozilla/layout/html/style/src/nsCSSFrameConstructor.h
+++ b/mozilla/layout/html/style/src/nsCSSFrameConstructor.h
@@ -50,7 +50,7 @@ class nsIDocument;
 struct nsFrameItems;
 struct nsAbsoluteItems;
 struct nsTableCreator;
-class nsIStyleContext;
+class nsStyleContext;
 struct nsTableList;
 struct nsStyleContent;
 struct nsStyleDisplay;
@@ -204,14 +204,14 @@ protected:
                                 nsFrameConstructorState& aState,
                                 nsIContent*              aContent,
                                 nsIFrame*                aParentFrame,
-                                nsIStyleContext*         aStyleContext,
+                                nsStyleContext*          aStyleContext,
                                 nsIFrame*                aPrevInFlow,
                                 nsIFrame*                aNewFrame);
 
-  nsresult ResolveStyleContext(nsIPresContext*   aPresContext,
-                               nsIFrame*         aParentFrame,
-                               nsIContent*       aContent,
-                               nsIStyleContext** aStyleContext);
+  already_AddRefed<nsStyleContext>
+  ResolveStyleContext(nsIPresContext*   aPresContext,
+                      nsIFrame*         aParentFrame,
+                      nsIContent*       aContent);
 
   nsresult ConstructFrame(nsIPresShell*            aPresShell,
                           nsIPresContext*          aPresContext,
@@ -225,7 +225,7 @@ protected:
                                     nsFrameConstructorState& aState,
                                     nsIContent*              aDocElement,
                                     nsIFrame*                aParentFrame,
-                                    nsIStyleContext*         aParentStyleContext,
+                                    nsStyleContext*          aParentStyleContext,
                                     nsIFrame*&               aNewFrame);
 
   nsresult ConstructDocElementTableFrame(nsIPresShell*          aPresShell, 
@@ -239,7 +239,7 @@ protected:
                                    nsIDocument*          aDocument,
                                    nsIFrame*             aParentFrame,
                                    nsIContent*           aContent,
-                                   nsIStyleContext*      aStyleContext,
+                                   nsStyleContext*       aStyleContext,
                                    const nsStyleContent* aStyleContent,
                                    PRUint32              aContentIndex,
                                    nsIFrame**            aFrame);
@@ -249,7 +249,7 @@ protected:
                                      nsFrameConstructorState& aState,
                                      nsIFrame*                aFrame,
                                      nsIContent*              aContent,
-                                     nsIStyleContext*         aStyleContext,
+                                     nsStyleContext*          aStyleContext,
                                      nsIAtom*                 aPseudoElement,
                                      nsIFrame**               aWrapperFrame,
                                      nsIFrame**               aResult);
@@ -267,7 +267,7 @@ protected:
                                nsFrameConstructorState& aState,
                                nsIContent*              aContent,
                                nsIFrame*                aParent,
-                               nsIStyleContext*         aStyleContext,
+                               nsStyleContext*          aStyleContext,
                                nsTableCreator&          aTableCreator,
                                PRBool                   aIsPseudo,
                                nsFrameItems&            aChildItems,
@@ -280,7 +280,7 @@ protected:
                                       nsFrameConstructorState& aState,
                                       nsIContent*              aContent,
                                       nsIFrame*                aParent,
-                                      nsIStyleContext*         aStyleContext,
+                                      nsStyleContext*          aStyleContext,
                                       nsTableCreator&          aTableCreator,
                                       nsFrameItems&            aChildItems,
                                       nsIFrame*&               aNewFrame,
@@ -291,7 +291,7 @@ protected:
                                        nsFrameConstructorState& aState,
                                        nsIContent*              aContent,
                                        nsIFrame*                aParent,
-                                       nsIStyleContext*         aStyleContext,
+                                       nsStyleContext*          aStyleContext,
                                        nsTableCreator&          aTableCreator,
                                        PRBool                   aIsPseudo,
                                        nsFrameItems&            aChildItems,
@@ -303,7 +303,7 @@ protected:
                                        nsFrameConstructorState& aState,
                                        nsIContent*              aContent,
                                        nsIFrame*                aParent,
-                                       nsIStyleContext*         aStyleContext,
+                                       nsStyleContext*          aStyleContext,
                                        nsTableCreator&          aTableCreator,
                                        PRBool                   aIsPseudo,
                                        nsFrameItems&            aChildItems,
@@ -315,7 +315,7 @@ protected:
                                   nsFrameConstructorState& aState,
                                   nsIContent*              aContent,
                                   nsIFrame*                aParent,
-                                  nsIStyleContext*         aStyleContext,
+                                  nsStyleContext*          aStyleContext,
                                   nsTableCreator&          aTableCreator,
                                   PRBool                   aIsPseudo,
                                   nsFrameItems&            aChildItems,
@@ -327,7 +327,7 @@ protected:
                                   nsFrameConstructorState& aState,
                                   nsIContent*              aContent,
                                   nsIFrame*                aParent,
-                                  nsIStyleContext*         aStyleContext,
+                                  nsStyleContext*          aStyleContext,
                                   nsTableCreator&          aTableCreator,
                                   PRBool                   aIsPseudo,
                                   nsFrameItems&            aChildItems,
@@ -339,7 +339,7 @@ protected:
                                    nsFrameConstructorState& aState,
                                    nsIContent*              aContent,
                                    nsIFrame*                aParentFrame,
-                                   nsIStyleContext*         aStyleContext,
+                                   nsStyleContext*          aStyleContext,
                                    nsTableCreator&          aTableCreator,
                                    PRBool                   aIsPseudo,
                                    nsFrameItems&            aChildItems,
@@ -351,14 +351,14 @@ protected:
                                   nsIFrame*        aParentFrame,
                                   nsIAtom*         aTag,
                                   nsIContent*      aContent,
-                                  nsIStyleContext* aContext);
+                                  nsStyleContext*  aContext);
 
   nsresult ConstructTableForeignFrame(nsIPresShell*            aPresShell, 
                                       nsIPresContext*          aPresContext,
                                       nsFrameConstructorState& aState,
                                       nsIContent*              aContent,
                                       nsIFrame*                aParentFrameIn,
-                                      nsIStyleContext*         aStyleContext,
+                                      nsStyleContext*          aStyleContext,
                                       nsTableCreator&          aTableCreator,
                                       nsFrameItems&            aChildItems,
                                       nsIFrame*&               aNewFrame,
@@ -449,7 +449,7 @@ protected:
                              nsIContent*              aParentContent,
                              nsIFrame*                aParentFrame,
                              nsIAtom*                 aParentFrameType,
-                             nsIStyleContext*         aParentStyleContext,
+                             nsStyleContext*          aParentStyleContext,
                              nsTableCreator&          aTableCreator,
                              nsFrameItems&            aChildItems,
                              nsIFrame*&               aCaption);
@@ -463,14 +463,14 @@ protected:
                                      nsIFrameManager* aFrameManager,
                                      nsIContent*      aContent,
                                      nsIFrame*        aFrame,
-                                     nsIStyleContext* aStyleContext,
+                                     nsStyleContext*  aStyleContext,
                                      nsIFrame*        aParentFrame,
                                      nsIFrame**       aPlaceholderFrame);
 
   nsresult ConstructAlternateFrame(nsIPresShell*    aPresShell, 
                                    nsIPresContext*  aPresContext,
                                    nsIContent*      aContent,
-                                   nsIStyleContext* aStyleContext,
+                                   nsStyleContext*  aStyleContext,
                                    nsIFrame*        aParentFrame,
                                    nsIFrame*&       aFrame);
 
@@ -481,13 +481,13 @@ protected:
                                       nsIPresContext*    aPresContext,
                                       nsIFrame*&         aNewFrame,
                                       nsIContent*        aContent,
-                                      nsIStyleContext*   aStyleContext);
+                                      nsStyleContext*    aStyleContext);
 
   nsresult ConstructCheckboxControlFrame(nsIPresShell*    aPresShell, 
                                          nsIPresContext*  aPresContext,
                                          nsIFrame*&       aNewFrame,
                                          nsIContent*      aContent,
-                                         nsIStyleContext* aStyleContext);
+                                         nsStyleContext*  aStyleContext);
 
   nsresult ConstructButtonControlFrame(nsIPresShell*    aPresShell,
                                        nsIPresContext*  aPresContext,
@@ -505,7 +505,7 @@ protected:
                                 nsIContent*              aContent,
                                 nsIFrame*                aParentFrame,
                                 nsIAtom*                 aTag,
-                                nsIStyleContext*         aStyleContext,
+                                nsStyleContext*          aStyleContext,
                                 nsIFrame*&               aNewFrame,
                                 PRBool&                  aProcessChildren,
                                 PRBool                   aIsAbsolutelyPositioned,
@@ -519,7 +519,7 @@ protected:
                                   nsIContent*              aContent,
                                   nsIFrame*                aParentFrame,
                                   nsIAtom*                 aTag,
-                                  nsIStyleContext*         aStyleContext,
+                                  nsStyleContext*          aStyleContext,
                                   nsIFrame*&               aNewFrame,
                                   PRBool&                  aProcessChildren,
                                   PRBool                   aIsAbsolutelyPositioned,
@@ -531,7 +531,7 @@ protected:
                               nsFrameConstructorState& aState,
                               nsIContent*              aContent,
                               nsIFrame*                aParentFrame,
-                              nsIStyleContext*         aStyleContext,
+                              nsStyleContext*          aStyleContext,
                               nsFrameItems&            aFrameItems);
 
   nsresult ConstructPageBreakFrame(nsIPresShell*            aPresShell, 
@@ -539,7 +539,7 @@ protected:
                                    nsFrameConstructorState& aState,
                                    nsIContent*              aContent,
                                    nsIFrame*                aParentFrame,
-                                   nsIStyleContext*         aStyleContext,
+                                   nsStyleContext*          aStyleContext,
                                    nsFrameItems&            aFrameItems);
 
   // Construct a page break frame if page-break-before:always is set in aStyleContext
@@ -550,7 +550,7 @@ protected:
                          nsFrameConstructorState& aState,
                          nsIContent*              aContent,
                          nsIFrame*                aParentFrame,
-                         nsIStyleContext*         aStyleContext,
+                         nsStyleContext*          aStyleContext,
                          nsFrameItems&            aFrameItems);
 
   nsresult ConstructHTMLFrame(nsIPresShell*            aPresShell, 
@@ -560,7 +560,7 @@ protected:
                               nsIFrame*                aParentFrame,
                               nsIAtom*                 aTag,
                               PRInt32                  aNameSpaceID,
-                              nsIStyleContext*         aStyleContext,
+                              nsStyleContext*          aStyleContext,
                               nsFrameItems&            aFrameItems);
 
   nsresult ConstructFrameInternal( nsIPresShell*            aPresShell, 
@@ -570,7 +570,7 @@ protected:
                                    nsIFrame*                aParentFrame,
                                    nsIAtom*                 aTag,
                                    PRInt32                  aNameSpaceID,
-                                   nsIStyleContext*         aStyleContext,
+                                   nsStyleContext*          aStyleContext,
                                    nsFrameItems&            aFrameItems,
                                    PRBool                   aXBLBaseTag);
 
@@ -600,7 +600,7 @@ protected:
                                 nsIFrame*                aParentFrame,
                                 nsIAtom*                 aTag,
                                 PRInt32                  aNameSpaceID,
-                                nsIStyleContext*         aStyleContext,
+                                nsStyleContext*          aStyleContext,
                                 nsFrameItems&            aFrameItems);
 #endif
 
@@ -612,7 +612,7 @@ protected:
                              nsIFrame*                aParentFrame,
                              nsIAtom*                 aTag,
                              PRInt32                  aNameSpaceID,
-                             nsIStyleContext*         aStyleContext,
+                             nsStyleContext*          aStyleContext,
                              nsFrameItems&            aFrameItems,
                              PRBool                   aXBLBaseTag,
                              PRBool&                  aHaltProcessing);
@@ -628,7 +628,7 @@ protected:
                                 nsIFrame*                aParentFrame,
                                 nsIAtom*                 aTag,
                                 PRInt32                  aNameSpaceID,
-                                nsIStyleContext*         aStyleContext,
+                                nsStyleContext*          aStyleContext,
                                 nsFrameItems&            aFrameItems);
 #endif
 
@@ -640,7 +640,7 @@ protected:
                                        PRInt32                  aNameSpaceID,
                                        nsIAtom*                 aTag,
                                        nsIFrame*                aParentFrame,
-                                       nsIStyleContext*         aStyleContext,
+                                       nsStyleContext*          aStyleContext,
                                        nsFrameItems&            aFrameItems);
 
   nsresult ProcessChildren(nsIPresShell*            aPresShell, 
@@ -657,7 +657,7 @@ protected:
                             nsIPresContext*  aPresContext,
                             nsIContent*      aContent,
                             nsIFrame*&       aFrame,
-                            nsIStyleContext* aStyleContext);
+                            nsStyleContext*  aStyleContext);
 
   nsresult AddDummyFrameToSelect(nsIPresContext*          aPresContext,
                                  nsIPresShell*            aPresShell,
@@ -697,28 +697,27 @@ protected:
                    nsIPresContext*          aPresContext,
                    nsFrameConstructorState& aState,
                    nsIContent*              aContent,
-                   nsIStyleContext*         aContentStyle,
+                   nsStyleContext*          aContentStyle,
                    nsIFrame*                aScrolledFrame,
                    nsIFrame*                aParentFrame,
                    nsIFrame*&               aNewFrame,
-                   nsIStyleContext*&        aScrolledChildStyle,
+                   nsStyleContext*&         aScrolledChildStyle,
                    nsIFrame*                aScrollPort = nsnull);
 
   // Builds the initial ScrollFrame: 
   //  if Gfx scrollbasrs in ares, it creates a GfxScrollFrame, otherwise it creates a ScrollFrame
   //
-  nsresult
+  already_AddRefed<nsStyleContext>
   BeginBuildingScrollFrame(nsIPresShell*            aPresShell, 
                            nsIPresContext*          aPresContext,
                            nsFrameConstructorState& aState,
                            nsIContent*              aContent,
-                           nsIStyleContext*         aContentStyle,
+                           nsStyleContext*          aContentStyle,
                            nsIFrame*                aParentFrame,
                            nsIAtom*                 aScrolledPseudo,
                            nsIDocument*             aDocument,
                            PRBool                   aIsRoot,
                            nsIFrame*&               aNewFrame, 
-                           nsCOMPtr<nsIStyleContext>& aScrolledChildStyle,
                            nsIFrame*&               aScrollableFrame,
                            nsIFrame*                aScrollPort = nsnull);
 
@@ -731,7 +730,7 @@ protected:
                             nsIContent*              aContent,
                             nsIFrame*                aScrollFrame,
                             nsIFrame*                aScrolledFrame,
-                            nsIStyleContext*         scrolledPseudoStyle);
+                            nsStyleContext*          scrolledPseudoStyle);
 
   // Creates a new GfxScrollFrame, Initializes it, and creates a scroll port for it
   //
@@ -742,7 +741,7 @@ protected:
                       nsIContent*              aContent,
                       nsIDocument*             aDocument,
                       nsIFrame*                aParentFrame,
-                      nsIStyleContext*         aStyleContext,
+                      nsStyleContext*          aStyleContext,
                       PRBool                   aIsRoot,
                       nsIFrame*&               aNewFrame,
                       nsFrameItems&            aAnonymousFrames,
@@ -757,7 +756,7 @@ protected:
                         nsIFrame*                scrolledFrame,
                         nsIContent*              aContent,
                         nsIFrame*                aParentFrame,
-                        nsIStyleContext*         aStyleContext,
+                        nsStyleContext*          aStyleContext,
                         PRBool                   aIsAbsolutelyPositioned,
                         PRBool                   aIsFixedPositioned,
                         PRBool                   aCreateBlock);
@@ -771,7 +770,7 @@ protected:
                                     nsIContent*      aContent, 
                                     PRBool           aInlineStyle = PR_FALSE,
                                     nsIStyleRule*    aRule = nsnull,
-                                    nsIStyleContext* aContext = nsnull);
+                                    nsStyleContext*  aContext = nsnull);
 
   nsresult RecreateFramesOnAttributeChange(nsIPresContext* aPresContext,
                                            nsIContent*     aContent,
@@ -782,7 +781,7 @@ protected:
                                            nsIFrame*        aFrame,
                                            nsIFrame*        aParentFrame,
                                            nsIContent*      aContent,
-                                           nsIStyleContext* aStyleContext,
+                                           nsStyleContext*  aStyleContext,
                                            nsIFrame**       aContinuingFrame);
 
   nsresult CreateContinuingTableFrame(nsIPresShell*    aPresShell, 
@@ -790,32 +789,34 @@ protected:
                                       nsIFrame*        aFrame,
                                       nsIFrame*        aParentFrame,
                                       nsIContent*      aContent,
-                                      nsIStyleContext* aStyleContext,
+                                      nsStyleContext*  aStyleContext,
                                       nsIFrame**       aContinuingFrame);
 
   //----------------------------------------
 
   // Methods support creating block frames and their children
 
-  static nsIStyleContext* GetFirstLetterStyle(nsIPresContext*  aPresContext,
-                                              nsIContent*      aContent,
-                                              nsIStyleContext* aStyleContext);
+  static already_AddRefed<nsStyleContext>
+  GetFirstLetterStyle(nsIPresContext*  aPresContext,
+                      nsIContent*      aContent,
+                      nsStyleContext*  aStyleContext);
 
-  static nsIStyleContext* GetFirstLineStyle(nsIPresContext*  aPresContext,
-                                            nsIContent*      aContent,
-                                            nsIStyleContext* aStyleContext);
+  static already_AddRefed<nsStyleContext>
+  GetFirstLineStyle(nsIPresContext*  aPresContext,
+                    nsIContent*      aContent,
+                    nsStyleContext*  aStyleContext);
 
   static PRBool HaveFirstLetterStyle(nsIPresContext*  aPresContext,
                                      nsIContent*      aContent,
-                                     nsIStyleContext* aStyleContext);
+                                     nsStyleContext*  aStyleContext);
 
   static PRBool HaveFirstLineStyle(nsIPresContext*  aPresContext,
                                    nsIContent*      aContent,
-                                   nsIStyleContext* aStyleContext);
+                                   nsStyleContext*  aStyleContext);
 
   static void HaveSpecialBlockStyle(nsIPresContext*  aPresContext,
                                     nsIContent*      aContent,
-                                    nsIStyleContext* aStyleContext,
+                                    nsStyleContext*  aStyleContext,
                                     PRBool*          aHaveFirstLetterStyle,
                                     PRBool*          aHaveFirstLineStyle);
 
@@ -829,7 +830,7 @@ protected:
                           const nsStyleDisplay*    aDisplay,
                           nsIContent*              aContent,
                           nsIFrame*                aParentFrame,
-                          nsIStyleContext*         aStyleContext,
+                          nsStyleContext*          aStyleContext,
                           nsIFrame*                aNewFrame,
                           PRBool                   aRelPos);
 
@@ -848,7 +849,7 @@ protected:
                            const nsStyleDisplay*    aDisplay,
                            nsIContent*              aContent,
                            nsIFrame*                aParentFrame,
-                           nsIStyleContext*         aStyleContext,
+                           nsStyleContext*          aStyleContext,
                            PRBool                   aIsPositioned,
                            nsIFrame*                aNewFrame,
                            nsIFrame**               aNewBlockFrame,
@@ -925,7 +926,7 @@ protected:
                                  nsIFrame*                aTextFrame,
                                  nsIContent*              aBlockContent,
                                  nsIFrame*                aParentFrame,
-                                 nsIStyleContext*         aStyleContext,
+                                 nsStyleContext*          aStyleContext,
                                  nsFrameItems&            aResult);
 
   nsresult CreateLetterFrame(nsIPresShell*            aPresShell, 
diff --git a/mozilla/layout/html/style/src/nsCSSRendering.cpp b/mozilla/layout/html/style/src/nsCSSRendering.cpp
index 60d446d824e..cfb8d8bc5fd 100644
--- a/mozilla/layout/html/style/src/nsCSSRendering.cpp
+++ b/mozilla/layout/html/style/src/nsCSSRendering.cpp
@@ -43,7 +43,7 @@
 #include "nsRect.h"
 #include "nsIViewManager.h"
 #include "nsIPresShell.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIScrollableView.h"
 #include "nsLayoutAtoms.h"
 #include "nsIDrawingSurface.h"
@@ -1562,8 +1562,7 @@ PRBool GetBGColorForHTMLElement( nsIPresContext *aPresContext,
             // use this guy's color
             nsIFrame *pFrame = nsnull;
             if (NS_SUCCEEDED(shell->GetPrimaryFrameFor(pContent, &pFrame)) && pFrame) {
-              nsIStyleContext *pContext = nsnull;
-              pFrame->GetStyleContext(&pContext);
+              nsStyleContext *pContext = pFrame->GetStyleContext();
               if (pContext) {
                 const nsStyleBackground* color = (const nsStyleBackground*)pContext->GetStyleData(eStyleStruct_Background);
                 NS_ASSERTION(color,"ColorStyleData should not be null");
@@ -1572,7 +1571,6 @@ PRBool GetBGColorForHTMLElement( nsIPresContext *aPresContext,
                   // set the reslt to TRUE to indicate we mapped the color
                   result = PR_TRUE;
                 }
-                NS_RELEASE(pContext);
               }// if context
             }// if frame
           }// if tag == html or body
@@ -1672,7 +1670,7 @@ void nsCSSRendering::PaintBorder(nsIPresContext* aPresContext,
                                  const nsRect& aDirtyRect,
                                  const nsRect& aBorderArea,
                                  const nsStyleBorder& aBorderStyle,
-                                 nsIStyleContext* aStyleContext,
+                                 nsStyleContext* aStyleContext,
                                  PRIntn aSkipSides,
                                  nsRect* aGap,
                                  nscoord aHardBorderSize,
@@ -2070,7 +2068,7 @@ void nsCSSRendering::PaintOutline(nsIPresContext* aPresContext,
                                  const nsRect& aBorderArea,
                                  const nsStyleBorder& aBorderStyle,
                                  const nsStyleOutline& aOutlineStyle,
-                                 nsIStyleContext* aStyleContext,
+                                 nsStyleContext* aStyleContext,
                                  PRIntn aSkipSides,
                                  nsRect* aGap)
 {
@@ -2233,7 +2231,7 @@ void nsCSSRendering::PaintBorderEdges(nsIPresContext* aPresContext,
                                       const nsRect& aDirtyRect,
                                       const nsRect& aBorderArea,
                                       nsBorderEdges * aBorderEdges,
-                                      nsIStyleContext* aStyleContext,
+                                      nsStyleContext* aStyleContext,
                                       PRIntn aSkipSides,
                                       nsRect* aGap)
 {
@@ -2527,11 +2525,11 @@ GetRootScrollableFrame(nsIPresContext* aPresContext, nsIFrame* aRootFrame)
 }
 
 const nsStyleBackground*
-nsCSSRendering::FindNonTransparentBackground(nsIStyleContext* aContext,
+nsCSSRendering::FindNonTransparentBackground(nsStyleContext* aContext,
                                              PRBool aStartAtParent /*= PR_FALSE*/)
 {
   const nsStyleBackground* result = nsnull;
-  nsCOMPtr<nsIStyleContext> context;
+  nsStyleContext* context;
   if (aStartAtParent) {
     context = aContext->GetParent();
   } else {
@@ -2543,7 +2541,7 @@ nsCSSRendering::FindNonTransparentBackground(nsIStyleContext* aContext,
     // Have to .get() because some compilers won't match the template
     // otherwise (they don't look for implicit type conversions while doing
     // template matching?).
-    ::GetStyleData(context.get(), &result);
+    ::GetStyleData(context, &result);
     if (0 == (result->mBackgroundFlags & NS_STYLE_BG_COLOR_TRANSPARENT))
       break;
 
@@ -2609,7 +2607,7 @@ FindCanvasBackground(nsIPresContext* aPresContext,
   
     // for printing and print preview.. this should be a pageContentFrame
     nsCOMPtr<nsIAtom> frameType;
-    nsCOMPtr<nsIStyleContext> parentContext;
+    nsStyleContext* parentContext;
 
     firstChild->GetFrameType(getter_AddRefs(frameType));
     if ( (frameType == nsLayoutAtoms::pageContentFrame) ){
@@ -2617,11 +2615,11 @@ FindCanvasBackground(nsIPresContext* aPresContext,
       // pageContentframe does not have content
       while(firstChild){
         for (nsIFrame* kidFrame = firstChild; nsnull != kidFrame; ) {
-          kidFrame->GetStyleContext(getter_AddRefs(parentContext));
+          parentContext = kidFrame->GetStyleContext();
           // Need to .get() because some compilers will not do the
           // implicit .get() to match the template.
           // See also rev 3.188 of this file.
-          ::GetStyleData(parentContext.get(), &result);
+          ::GetStyleData(parentContext, &result);
           if (!result->IsTransparent()) {
             GetStyleData(kidFrame, aBackground);
             return PR_TRUE;
@@ -3504,7 +3502,7 @@ nsCSSRendering::PaintRoundedBorder(nsIPresContext* aPresContext,
                                  const nsRect& aBorderArea,
                                  const nsStyleBorder* aBorderStyle,
                                  const nsStyleOutline* aOutlineStyle,
-                                 nsIStyleContext* aStyleContext,
+                                 nsStyleContext* aStyleContext,
                                  PRIntn aSkipSides,
                                  PRInt16 aBorderRadius[4],
                                  nsRect* aGap,
@@ -3643,7 +3641,7 @@ nsCSSRendering::PaintRoundedBorder(nsIPresContext* aPresContext,
  */
 void 
 nsCSSRendering::RenderSide(nsFloatPoint aPoints[],nsIRenderingContext& aRenderingContext,
-                        const nsStyleBorder* aBorderStyle,const nsStyleOutline* aOutlineStyle,nsIStyleContext* aStyleContext,
+                        const nsStyleBorder* aBorderStyle,const nsStyleOutline* aOutlineStyle,nsStyleContext* aStyleContext,
                         PRUint8 aSide,nsMargin  &aBorThick,nscoord aTwipsPerPixel,
                         PRBool aIsOutline)
 {
diff --git a/mozilla/layout/html/style/src/nsCSSRendering.h b/mozilla/layout/html/style/src/nsCSSRendering.h
index a12f889f35e..ce3e138e10c 100644
--- a/mozilla/layout/html/style/src/nsCSSRendering.h
+++ b/mozilla/layout/html/style/src/nsCSSRendering.h
@@ -39,7 +39,7 @@
 
 #include "nsIRenderingContext.h"
 struct nsPoint;
-class nsIStyleContext;
+class nsStyleContext;
 class nsIPresContext;
 
 class nsCSSRendering {
@@ -58,7 +58,7 @@ public:
                           const nsRect& aDirtyRect,
                           const nsRect& aBorderArea,
                           const nsStyleBorder& aBorderStyle,
-                          nsIStyleContext* aStyleContext,
+                          nsStyleContext* aStyleContext,
                           PRIntn aSkipSides,
                           nsRect* aGap = 0,
                           nscoord aHardBorderSize = 0,
@@ -79,7 +79,7 @@ public:
                           const nsRect& aBorderArea,
                           const nsStyleBorder& aBorderStyle,
                           const nsStyleOutline& aOutlineStyle,
-                          nsIStyleContext* aStyleContext,
+                          nsStyleContext* aStyleContext,
                           PRIntn aSkipSides,
                           nsRect* aGap = 0);
 
@@ -100,7 +100,7 @@ public:
                                const nsRect& aDirtyRect,
                                const nsRect& aBorderArea,
                                nsBorderEdges * aBorderEdges,
-                               nsIStyleContext* aStyleContext,
+                               nsStyleContext* aStyleContext,
                                PRIntn aSkipSides,
                                nsRect* aGap = 0);
 
@@ -123,7 +123,7 @@ public:
    * you want.
    */
   static const nsStyleBackground*
-  FindNonTransparentBackground(nsIStyleContext* aContext,
+  FindNonTransparentBackground(nsStyleContext* aContext,
                                PRBool aStartAtParent = PR_FALSE);
 
   /**
@@ -232,13 +232,13 @@ protected:
                           const nsRect& aBorderArea,
                           const nsStyleBorder* aBorderStyle,
                           const nsStyleOutline* aOutlineStyle,
-                          nsIStyleContext* aStyleContext,
+                          nsStyleContext* aStyleContext,
                           PRIntn aSkipSides,
                           PRInt16 aBorderRadius[4],nsRect* aGap = 0,
                           PRBool aIsOutline=PR_FALSE);
 
   static void RenderSide(nsFloatPoint aPoints[],nsIRenderingContext& aRenderingContext,
-                        const nsStyleBorder* aBorderStyle,const nsStyleOutline* aOutlineStyle,nsIStyleContext* aStyleContext,
+                        const nsStyleBorder* aBorderStyle,const nsStyleOutline* aOutlineStyle,nsStyleContext* aStyleContext,
                         PRUint8 aSide,nsMargin  &aBorThick,nscoord aTwipsPerPixel,
                         PRBool aIsOutline=PR_FALSE);
 
diff --git a/mozilla/layout/html/table/src/nsTableCellFrame.cpp b/mozilla/layout/html/table/src/nsTableCellFrame.cpp
index 3d7d4b7f04e..7b3c7e1d7b9 100644
--- a/mozilla/layout/html/table/src/nsTableCellFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableCellFrame.cpp
@@ -41,7 +41,7 @@
 #include "nsTableFrame.h"
 #include "nsTableRowGroupFrame.h"
 #include "nsReflowPath.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIPresContext.h"
 #include "nsIRenderingContext.h"
@@ -116,7 +116,7 @@ NS_IMETHODIMP
 nsTableCellFrame::Init(nsIPresContext*  aPresContext,
                        nsIContent*      aContent,
                        nsIFrame*        aParent,
-                       nsIStyleContext* aContext,
+                       nsStyleContext*  aContext,
                        nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
diff --git a/mozilla/layout/html/table/src/nsTableCellFrame.h b/mozilla/layout/html/table/src/nsTableCellFrame.h
index 79c6abdb838..4db09980812 100644
--- a/mozilla/layout/html/table/src/nsTableCellFrame.h
+++ b/mozilla/layout/html/table/src/nsTableCellFrame.h
@@ -41,7 +41,7 @@
 #include "nscore.h"
 #include "nsHTMLContainerFrame.h"
 #include "nsTableRowFrame.h"  // need to actually include this here to inline GetRowIndex
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIPercentHeightObserver.h"
 #include "nsLayoutAtoms.h"
 
@@ -85,7 +85,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
 #ifdef ACCESSIBILITY
diff --git a/mozilla/layout/html/table/src/nsTableColFrame.cpp b/mozilla/layout/html/table/src/nsTableColFrame.cpp
index 3bf577d733b..4a12e9da353 100644
--- a/mozilla/layout/html/table/src/nsTableColFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableColFrame.cpp
@@ -37,7 +37,7 @@
 #include "nsCOMPtr.h"
 #include "nsTableColFrame.h"
 #include "nsContainerFrame.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIPresContext.h"
 #include "nsHTMLAtoms.h"
@@ -116,8 +116,7 @@ nsStyleCoord nsTableColFrame::GetStyleWidth() const
       eStyleUnit_Inherit == styleWidth.GetUnit()) {
     nsIFrame* parent;
     GetParent(&parent);
-    nsCOMPtr<nsIStyleContext> styleContext;
-    parent->GetStyleContext(getter_AddRefs(styleContext)); 
+    nsStyleContext* styleContext = parent->GetStyleContext();
     if (styleContext) {
       position = (nsStylePosition*)styleContext->GetStyleData(eStyleStruct_Position);
       styleWidth = position->mWidth;
@@ -269,7 +268,7 @@ NS_IMETHODIMP
 nsTableColFrame::Init(nsIPresContext*  aPresContext,
                       nsIContent*      aContent,
                       nsIFrame*        aParent,
-                      nsIStyleContext* aContext,
+                      nsStyleContext*  aContext,
                       nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
diff --git a/mozilla/layout/html/table/src/nsTableColFrame.h b/mozilla/layout/html/table/src/nsTableColFrame.h
index 505a84b3726..280efa9933b 100644
--- a/mozilla/layout/html/table/src/nsTableColFrame.h
+++ b/mozilla/layout/html/table/src/nsTableColFrame.h
@@ -107,7 +107,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Paint(nsIPresContext*      aPresContext,
diff --git a/mozilla/layout/html/table/src/nsTableColGroupFrame.cpp b/mozilla/layout/html/table/src/nsTableColGroupFrame.cpp
index ce3d2d53bb2..9221c4540ca 100644
--- a/mozilla/layout/html/table/src/nsTableColGroupFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableColGroupFrame.cpp
@@ -40,7 +40,7 @@
 #include "nsIHTMLTableColElement.h"
 #include "nsIDOMHTMLTableColElement.h"
 #include "nsReflowPath.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIPresContext.h"
 #include "nsIHTMLContent.h"
@@ -722,7 +722,7 @@ NS_IMETHODIMP
 nsTableColGroupFrame::Init(nsIPresContext*  aPresContext,
                            nsIContent*      aContent,
                            nsIFrame*        aParent,
-                           nsIStyleContext* aContext,
+                           nsStyleContext*  aContext,
                            nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
diff --git a/mozilla/layout/html/table/src/nsTableColGroupFrame.h b/mozilla/layout/html/table/src/nsTableColGroupFrame.h
index ffcb9cf2dff..d0f0f556882 100644
--- a/mozilla/layout/html/table/src/nsTableColGroupFrame.h
+++ b/mozilla/layout/html/table/src/nsTableColGroupFrame.h
@@ -73,7 +73,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD SetInitialChildList(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/html/table/src/nsTableFrame.cpp b/mozilla/layout/html/table/src/nsTableFrame.cpp
index eb09677fa04..13d4ee48758 100644
--- a/mozilla/layout/html/table/src/nsTableFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableFrame.cpp
@@ -39,7 +39,7 @@
 #include "nsVoidArray.h"
 #include "nsTableFrame.h"
 #include "nsIRenderingContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIContent.h"
 #include "nsCellMap.h"
@@ -76,7 +76,7 @@
 #include "nsIFrameManager.h"
 #include "nsCSSRendering.h"
 #include "nsLayoutErrors.h"
-
+#include "nsAutoPtr.h"
 
 
 /********************************************************************************
@@ -247,7 +247,7 @@ NS_IMETHODIMP
 nsTableFrame::Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
@@ -377,8 +377,8 @@ PRBool
 nsTableFrame::PageBreakAfter(nsIFrame& aSourceFrame,
                              nsIFrame* aNextFrame)
 {
-  nsCOMPtr<nsIStyleContext> sourceContext;
-  aSourceFrame.GetStyleContext(getter_AddRefs(sourceContext)); NS_ENSURE_TRUE(sourceContext, PR_FALSE);
+  nsStyleContext* sourceContext = aSourceFrame.GetStyleContext();
+  NS_ENSURE_TRUE(sourceContext, PR_FALSE);
   const nsStyleDisplay* display = (const nsStyleDisplay*)
     sourceContext->GetStyleData(eStyleStruct_Display);         NS_ENSURE_TRUE(display, PR_FALSE); 
   // don't allow a page break after a repeated header
@@ -387,8 +387,8 @@ nsTableFrame::PageBreakAfter(nsIFrame& aSourceFrame,
   }
 
   if (aNextFrame) {
-    nsCOMPtr<nsIStyleContext> nextContext;
-    aNextFrame->GetStyleContext(getter_AddRefs(nextContext));  NS_ENSURE_TRUE(nextContext, PR_FALSE);
+    nsStyleContext* nextContext = aNextFrame->GetStyleContext();
+    NS_ENSURE_TRUE(nextContext, PR_FALSE);
     display = (const nsStyleDisplay*)
       nextContext->GetStyleData(eStyleStruct_Display);         NS_ENSURE_TRUE(display, PR_FALSE); 
     // don't allow a page break before a repeated footer
@@ -860,11 +860,10 @@ nsTableFrame::CreateAnonymousColGroupFrame(nsIPresContext&     aPresContext,
   nsCOMPtr<nsIContent> colGroupContent;
   GetContent(getter_AddRefs(colGroupContent));
 
-  nsCOMPtr<nsIStyleContext> colGroupStyle;
-  aPresContext.ResolvePseudoStyleContextFor(colGroupContent,
-                                            nsCSSAnonBoxes::tableColGroup,
-                                            mStyleContext,
-                                            getter_AddRefs(colGroupStyle));        
+  nsRefPtr<nsStyleContext> colGroupStyle;
+  colGroupStyle = aPresContext.ResolvePseudoStyleContextFor(colGroupContent,
+                                                            nsCSSAnonBoxes::tableColGroup,
+                                                            mStyleContext);
   // Create a col group frame
   nsIFrame* newFrame;
   nsCOMPtr<nsIPresShell> presShell;
@@ -967,21 +966,22 @@ nsTableFrame::CreateAnonymousColFrames(nsIPresContext&       aPresContext,
 
   for (PRInt32 childX = startIndex; childX <= lastIndex; childX++) {
     nsCOMPtr<nsIContent> iContent;
-    nsCOMPtr<nsIStyleContext> styleContext;
-    nsCOMPtr<nsIStyleContext> parentStyleContext;
+    nsRefPtr<nsStyleContext> styleContext;
+    nsStyleContext* parentStyleContext;
 
     if ((aColType == eColAnonymousCol) && aPrevFrameIn) {
       // a col due to a span in a previous col uses the style context of the col
-      aPrevFrameIn->GetStyleContext(getter_AddRefs(styleContext)); 
+      styleContext = aPrevFrameIn->GetStyleContext();
       // fix for bugzilla bug 54454: get the content from the prevFrame 
       aPrevFrameIn->GetContent(getter_AddRefs(iContent));
     }
     else {
       // all other anonymous cols use a pseudo style context of the col group
       aColGroupFrame.GetContent(getter_AddRefs(iContent));
-      aColGroupFrame.GetStyleContext(getter_AddRefs(parentStyleContext));
-      aPresContext.ResolvePseudoStyleContextFor(iContent, nsCSSAnonBoxes::tableCol,
-                                                parentStyleContext, getter_AddRefs(styleContext));
+      parentStyleContext = aColGroupFrame.GetStyleContext();
+      styleContext = aPresContext.ResolvePseudoStyleContextFor(iContent,
+                                                               nsCSSAnonBoxes::tableCol,
+                                                               parentStyleContext);
     }
     // ASSERTION to check for bug 54454 sneaking back in...
     NS_ASSERTION(iContent, "null content in CreateAnonymousColFrames");
@@ -2867,7 +2867,7 @@ nsTableFrame::GetBCBorder(nsIPresContext& aPresContext,
 static
 void GetSeparateModelBorderPadding(nsIPresContext&          aPresContext,
                                    const nsHTMLReflowState* aReflowState,
-                                   nsIStyleContext&         aStyleContext,
+                                   nsStyleContext&          aStyleContext,
                                    nsMargin&                aBorderPadding)
 {
   const nsStyleBorder* border =
@@ -3775,7 +3775,7 @@ UpdateCol(nsTableFrame&           aTableFrame,
 }
 
 PRBool 
-nsTableFrame::IsPctHeight(nsIStyleContext* aStyleContext) 
+nsTableFrame::IsPctHeight(nsStyleContext* aStyleContext) 
 {
   PRBool result = PR_FALSE;
   if (aStyleContext) {
@@ -4164,10 +4164,8 @@ PRBool
 nsTableFrame::IsAutoHeight()
 {
   PRBool isAuto = PR_TRUE;  // the default
-  nsCOMPtr<nsIStyleContext> styleContext;
-  GetStyleContext(getter_AddRefs(styleContext)); 
 
-  nsStylePosition* position = (nsStylePosition*)styleContext->GetStyleData(eStyleStruct_Position);
+  nsStylePosition* position = (nsStylePosition*)mStyleContext->GetStyleData(eStyleStruct_Position);
 
   switch (position->mHeight.GetUnit()) {
     case eStyleUnit_Auto:         // specified auto width
@@ -5171,8 +5169,8 @@ GetStyleInfo(const nsIFrame&  aFrame,
   PRBool transparent, foreground;
   styleData->GetBorderColor(aSide, aColor, transparent, foreground);
   if (foreground) {
-    nsCOMPtr<nsIStyleContext> styleContext;
-    aFrame.GetStyleContext(getter_AddRefs(styleContext)); if(!styleContext) ABORT0();
+    nsStyleContext* styleContext = aFrame.GetStyleContext();
+    if(!styleContext) ABORT0();
     const nsStyleColor* colorStyle = (const nsStyleColor*)styleContext->GetStyleData(eStyleStruct_Color);
     aColor = colorStyle->mColor;
   }
diff --git a/mozilla/layout/html/table/src/nsTableFrame.h b/mozilla/layout/html/table/src/nsTableFrame.h
index c355542df8c..fef8f6c3f41 100644
--- a/mozilla/layout/html/table/src/nsTableFrame.h
+++ b/mozilla/layout/html/table/src/nsTableFrame.h
@@ -42,7 +42,6 @@
 #include "nsHTMLContainerFrame.h"
 #include "nsStyleCoord.h"
 #include "nsStyleConsts.h"
-#include "nsIStyleContext.h"
 #include "nsITableLayout.h"
 #include "nsTableColFrame.h"
 #include "nsTableColGroupFrame.h"
@@ -56,6 +55,7 @@ class nsTableRowFrame;
 class nsTableColGroupFrame;
 class nsITableLayoutStrategy;
 class nsHTMLValue;
+class nsStyleContext;
 
 struct nsTableReflowState;
 struct nsStylePosition;
@@ -203,7 +203,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
 
@@ -293,7 +293,7 @@ public:
                                       nsIAtom*        aChildType);
   PRBool IsAutoWidth(PRBool* aIsPctWidth = nsnull);
   PRBool IsAutoHeight();
-  static PRBool IsPctHeight(nsIStyleContext* aStyleContext);
+  static PRBool IsPctHeight(nsStyleContext* aStyleContext);
   
   /** @return PR_TRUE if aDisplayType represents a rowgroup of any sort
     * (header, footer, or body)
diff --git a/mozilla/layout/html/table/src/nsTableOuterFrame.cpp b/mozilla/layout/html/table/src/nsTableOuterFrame.cpp
index ec74829dc95..355b0e716fb 100644
--- a/mozilla/layout/html/table/src/nsTableOuterFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableOuterFrame.cpp
@@ -38,7 +38,7 @@
 #include "nsTableOuterFrame.h"
 #include "nsTableFrame.h"
 #include "nsHTMLReflowCommand.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIPresContext.h"
 #include "nsIRenderingContext.h"
@@ -166,7 +166,7 @@ NS_IMETHODIMP
 nsTableOuterFrame::Init(nsIPresContext*  aPresContext,
                    nsIContent*           aContent,
                    nsIFrame*             aParent,
-                   nsIStyleContext*      aContext,
+                   nsStyleContext*       aContext,
                    nsIFrame*             aPrevInFlow)
 {
   nsresult rv = nsHTMLContainerFrame::Init(aPresContext, aContent, aParent, 
@@ -1231,8 +1231,7 @@ nsTableOuterFrame::IsAutoWidth(nsIFrame& aTableOrCaption,
     *aIsPctWidth = PR_FALSE;
   }
 
-  nsCOMPtr<nsIStyleContext> styleContext;
-  aTableOrCaption.GetStyleContext(getter_AddRefs(styleContext)); 
+  nsStyleContext* styleContext = aTableOrCaption.GetStyleContext();
 
   nsStylePosition* position = (nsStylePosition*)styleContext->GetStyleData(eStyleStruct_Position);
 
@@ -1877,8 +1876,7 @@ static PRBool
 IsPctHeight(nsIFrame* aFrame)
 {
   if (aFrame) {
-    nsCOMPtr<nsIStyleContext> styleContext;
-    aFrame->GetStyleContext(getter_AddRefs(styleContext)); 
+    nsStyleContext* styleContext = aFrame->GetStyleContext();
     nsStylePosition* position = (nsStylePosition*)styleContext->GetStyleData(eStyleStruct_Position);
     if (eStyleUnit_Percent == position->mHeight.GetUnit()) {
       float percent = position->mHeight.GetPercentValue();
diff --git a/mozilla/layout/html/table/src/nsTableOuterFrame.h b/mozilla/layout/html/table/src/nsTableOuterFrame.h
index ed72a539aa3..351bfe535ba 100644
--- a/mozilla/layout/html/table/src/nsTableOuterFrame.h
+++ b/mozilla/layout/html/table/src/nsTableOuterFrame.h
@@ -91,7 +91,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
diff --git a/mozilla/layout/html/table/src/nsTableRowFrame.cpp b/mozilla/layout/html/table/src/nsTableRowFrame.cpp
index 70d6baf0246..138bc5ca288 100644
--- a/mozilla/layout/html/table/src/nsTableRowFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableRowFrame.cpp
@@ -39,7 +39,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresShell.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIHTMLContent.h"
 #include "nsHTMLAtoms.h"
@@ -190,7 +190,7 @@ NS_IMETHODIMP
 nsTableRowFrame::Init(nsIPresContext*  aPresContext,
                       nsIContent*      aContent,
                       nsIFrame*        aParent,
-                      nsIStyleContext* aContext,
+                      nsStyleContext*  aContext,
                       nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
diff --git a/mozilla/layout/html/table/src/nsTableRowFrame.h b/mozilla/layout/html/table/src/nsTableRowFrame.h
index bf08c32e7a4..aa46d78af04 100644
--- a/mozilla/layout/html/table/src/nsTableRowFrame.h
+++ b/mozilla/layout/html/table/src/nsTableRowFrame.h
@@ -69,7 +69,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD SetInitialChildList(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/html/table/src/nsTableRowGroupFrame.cpp b/mozilla/layout/html/table/src/nsTableRowGroupFrame.cpp
index 5a1b208c9bb..e03dc0f4371 100644
--- a/mozilla/layout/html/table/src/nsTableRowGroupFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableRowGroupFrame.cpp
@@ -41,7 +41,7 @@
 #include "nsTableCellFrame.h"
 #include "nsIRenderingContext.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIContent.h"
 #include "nsIView.h"
@@ -1874,7 +1874,7 @@ NS_IMETHODIMP
 nsTableRowGroupFrame::Init(nsIPresContext*  aPresContext,
                            nsIContent*      aContent,
                            nsIFrame*        aParent,
-                           nsIStyleContext* aContext,
+                           nsStyleContext*  aContext,
                            nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
diff --git a/mozilla/layout/html/table/src/nsTableRowGroupFrame.h b/mozilla/layout/html/table/src/nsTableRowGroupFrame.h
index 6fc4bc81e64..1b82f15fdec 100644
--- a/mozilla/layout/html/table/src/nsTableRowGroupFrame.h
+++ b/mozilla/layout/html/table/src/nsTableRowGroupFrame.h
@@ -117,7 +117,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD AppendFrames(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/html/tests/TestInlineFrame.cpp b/mozilla/layout/html/tests/TestInlineFrame.cpp
index 8c81818fb17..affd69a2266 100644
--- a/mozilla/layout/html/tests/TestInlineFrame.cpp
+++ b/mozilla/layout/html/tests/TestInlineFrame.cpp
@@ -49,7 +49,7 @@
 #include "nsIPresContext.h"
 #include "nsInlineFrame.h"
 #include "nsIAtom.h"
-
+#include "nsAutoPtr.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 //
@@ -291,7 +291,7 @@ TestReflowUnmapped(nsIPresContext* presContext)
   // Create an inline frame for the HTML container and set its
   // style context
   InlineFrame*      f = new InlineFrame(b, 0, nsnull);
-  nsIStyleContext*  styleContext = presContext->ResolveStyleContextFor(b, nsnull);
+  nsRefPtr<nsStyleContext> styleContext = presContext->ResolveStyleContextFor(b, nsnull);
 
   f->SetStyleContext(presContext,styleContext);
 
@@ -384,7 +384,7 @@ TestChildrenThatDontFit(nsIPresContext* presContext)
   // Create an inline frame for the HTML container and set its
   // style context
   InlineFrame*      f = new InlineFrame(b, 0, nsnull);
-  nsIStyleContext*  styleContext = presContext->ResolveStyleContextFor(b, nsnull);
+  nsRefPtr<nsStyleContext> styleContext = presContext->ResolveStyleContextFor(b, nsnull);
 
   f->SetStyleContext(presContext,styleContext);
 
@@ -556,7 +556,7 @@ TestOverflow(nsIPresContext* presContext)
   // Create an inline frame for the HTML container and set its
   // style context
   InlineFrame*      f = new InlineFrame(b, 0, nsnull);
-  nsIStyleContext*  styleContext = presContext->ResolveStyleContextFor(b, nsnull);
+  nsRefPtr<nsStyleContext> styleContext = presContext->ResolveStyleContextFor(b, nsnull);
 
   f->SetStyleContext(presContext,styleContext);
 
@@ -668,7 +668,7 @@ TestPushingPulling(nsIPresContext* presContext)
   // Create an inline frame for the HTML container and set its
   // style context
   InlineFrame*      f = new InlineFrame(b, 0, nsnull);
-  nsIStyleContext*  styleContext = presContext->ResolveStyleContextFor(b, nsnull);
+  nsRefPtr<nsStyleContext> styleContext = presContext->ResolveStyleContextFor(b, nsnull);
 
   f->SetStyleContext(presContext,styleContext);
 
@@ -1089,7 +1089,7 @@ TestSplittableChildren(nsIPresContext* presContext)
   // Create an inline frame for the HTML container and set its
   // style context
   InlineFrame*      f = new InlineFrame(b, 0, nsnull);
-  nsIStyleContext*  styleContext = presContext->ResolveStyleContextFor(b, nsnull);
+  nsRefPtr<nsStyleContext> styleContext = presContext->ResolveStyleContextFor(b, nsnull);
 
   f->SetStyleContext(presContext,styleContext);
 
@@ -1448,7 +1448,7 @@ TestMaxElementSize(nsIPresContext* presContext)
   // Create an inline frame for the HTML container and set its
   // style context
   InlineFrame*      f = new InlineFrame(b, 0, nsnull);
-  nsIStyleContext*  styleContext = presContext->ResolveStyleContextFor(b, nsnull);
+  nsRefPtr<nsStyleContext> styleContext = presContext->ResolveStyleContextFor(b, nsnull);
 
   f->SetStyleContext(presContext,styleContext);
 
diff --git a/mozilla/layout/mathml/base/src/nsMathMLChar.cpp b/mozilla/layout/mathml/base/src/nsMathMLChar.cpp
index d59e94a41c9..1a153ca04eb 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLChar.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLChar.cpp
@@ -24,7 +24,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsString.h"
 #include "nsUnicharUtils.h"
@@ -1205,30 +1205,28 @@ InitGlobals(nsIPresContext* aPresContext)
 // -----------------------------------------------------------------------------------
 // And now the implementation of nsMathMLChar
 
-nsresult
-nsMathMLChar::GetStyleContext(nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsMathMLChar::GetStyleContext() const
 {
   NS_ASSERTION(!mParent, "invalid call - not allowed for child chars");
-  NS_PRECONDITION(aStyleContext, "null OUT ptr");
   NS_ASSERTION(mStyleContext, "chars shoud always have style context");
-  *aStyleContext = mStyleContext;
-  NS_IF_ADDREF(*aStyleContext);
+  return mStyleContext;
   return NS_OK;
 }
 
-nsresult
-nsMathMLChar::SetStyleContext(nsIStyleContext* aStyleContext)
+void
+nsMathMLChar::SetStyleContext(nsStyleContext* aStyleContext)
 {
   NS_ASSERTION(!mParent, "invalid call - not allowed for child chars");
   NS_PRECONDITION(aStyleContext, "null ptr");
   if (aStyleContext != mStyleContext) {
-    NS_IF_RELEASE(mStyleContext);
+    if (mStyleContext)
+      mStyleContext->Release();
     if (aStyleContext) {
       mStyleContext = aStyleContext;
-      NS_ADDREF(aStyleContext);
+      aStyleContext->AddRef();
     }
   }
-  return NS_OK;
 }
 
 void
@@ -1468,7 +1466,7 @@ nsMathMLChar::Stretch(nsIPresContext*      aPresContext,
   // mStyleContext is a leaf context used only when stretching happens.
   // For the base size, the default font should come from the parent context
   nsAutoString fontName;
-  nsCOMPtr<nsIStyleContext> parentContext(mStyleContext->GetParent());
+  nsStyleContext* parentContext = mStyleContext->GetParent();
   const nsStyleFont *font = NS_STATIC_CAST(const nsStyleFont*,
     parentContext->GetStyleData(eStyleStruct_Font));
   nsFont theFont(font->mFont);
@@ -1868,8 +1866,8 @@ nsMathMLChar::Paint(nsIPresContext*      aPresContext,
                     const nsRect*        aSelectedRect)
 {
   nsresult rv = NS_OK;
-  nsCOMPtr<nsIStyleContext> parentContext(mStyleContext->GetParent());
-  nsIStyleContext* styleContext = mStyleContext;
+  nsStyleContext* parentContext = mStyleContext->GetParent();
+  nsStyleContext* styleContext = mStyleContext;
 
   if (NS_STRETCH_DIRECTION_UNSUPPORTED == mDirection) {
     // normal drawing if there is nothing special about this char
@@ -1906,7 +1904,7 @@ nsMathMLChar::Paint(nsIPresContext*      aPresContext,
       const nsStyleBackground *backg = NS_STATIC_CAST(const nsStyleBackground*,
         styleContext->GetStyleData(eStyleStruct_Background));
       nsRect rect(mRect); //0, 0, mRect.width, mRect.height);
-      if (styleContext != parentContext.get() &&
+      if (styleContext != parentContext &&
           0 == (backg->mBackgroundFlags & NS_STYLE_BG_COLOR_TRANSPARENT))
         nsCSSRendering::PaintBackgroundWithSC(aPresContext, aRenderingContext, aForFrame,
                                               aDirtyRect, rect, *backg, *border, *padding,
@@ -2007,7 +2005,7 @@ nsresult
 nsMathMLChar::PaintVertically(nsIPresContext*      aPresContext,
                               nsIRenderingContext& aRenderingContext,
                               nsFont&              aFont,
-                              nsIStyleContext*     aStyleContext,
+                              nsStyleContext*      aStyleContext,
                               nsGlyphTable*        aGlyphTable,
                               nsMathMLChar*        aChar,
                               nsRect&              aRect)
@@ -2185,7 +2183,7 @@ nsresult
 nsMathMLChar::PaintHorizontally(nsIPresContext*      aPresContext,
                                 nsIRenderingContext& aRenderingContext,
                                 nsFont&              aFont,
-                                nsIStyleContext*     aStyleContext,
+                                nsStyleContext*      aStyleContext,
                                 nsGlyphTable*        aGlyphTable,
                                 nsMathMLChar*        aChar,
                                 nsRect&              aRect)
diff --git a/mozilla/layout/mathml/base/src/nsMathMLChar.h b/mozilla/layout/mathml/base/src/nsMathMLChar.h
index ad611ba3700..c3115b668a7 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLChar.h
+++ b/mozilla/layout/mathml/base/src/nsMathMLChar.h
@@ -65,8 +65,8 @@ public:
     MOZ_COUNT_DTOR(nsMathMLChar);
     // there is only one style context owned by the "root" char
     // and it may be used by child chars as well
-    if (!mParent) { // only the "root" need to release it
-      NS_IF_RELEASE(mStyleContext);
+    if (!mParent && mStyleContext) { // only the "root" need to release it
+      mStyleContext->Release();
     }
     if (mSibling) {
       delete mSibling;
@@ -156,11 +156,9 @@ public:
   // They provide an interface to make them acessible to the Style System via
   // the Get/Set AdditionalStyleContext() APIs. Owners of MathMLChars
   // should honor these APIs.
-  nsresult
-  GetStyleContext(nsIStyleContext** aStyleContext) const;
+  nsStyleContext* GetStyleContext() const;
 
-  nsresult
-  SetStyleContext(nsIStyleContext* aStyleContext);
+  void SetStyleContext(nsStyleContext* aStyleContext);
 
 protected:
   friend class nsGlyphTable;
@@ -175,7 +173,7 @@ private:
   PRInt32            mOperator;
   nsStretchDirection mDirection;
   nsBoundingMetrics  mBoundingMetrics;
-  nsIStyleContext*   mStyleContext;
+  nsStyleContext*    mStyleContext;
   nsGlyphTable*      mGlyphTable;
   nsGlyphCode        mGlyph;
 
@@ -192,7 +190,7 @@ private:
   PaintVertically(nsIPresContext*      aPresContext,
                   nsIRenderingContext& aRenderingContext,
                   nsFont&              aFont,
-                  nsIStyleContext*     aStyleContext,
+                  nsStyleContext*      aStyleContext,
                   nsGlyphTable*        aGlyphTable,
                   nsMathMLChar*        aChar,
                   nsRect&              aRect);
@@ -201,7 +199,7 @@ private:
   PaintHorizontally(nsIPresContext*      aPresContext,
                     nsIRenderingContext& aRenderingContext,
                     nsFont&              aFont,
-                    nsIStyleContext*     aStyleContext,
+                    nsStyleContext*      aStyleContext,
                     nsGlyphTable*        aGlyphTable,
                     nsMathMLChar*        aChar,
                     nsRect&              aRect);
diff --git a/mozilla/layout/mathml/base/src/nsMathMLContainerFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLContainerFrame.cpp
index 11e4d95cee3..2497b68a9c7 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLContainerFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLContainerFrame.cpp
@@ -29,7 +29,7 @@
 #include "nsIPresShell.h"
 #include "nsCSSAnonBoxes.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsINameSpaceManager.h"
 #include "nsIRenderingContext.h"
@@ -45,6 +45,7 @@
 #include "nsMathMLParts.h"
 #include "nsMathMLChar.h"
 #include "nsMathMLContainerFrame.h"
+#include "nsAutoPtr.h"
 
 //
 // nsMathMLContainerFrame implementation
@@ -592,9 +593,8 @@ nsMathMLContainerFrame::PropagateScriptStyleFor(nsIPresContext* aPresContext,
     // the one to use when we will propagate the recursion
     aParentScriptLevel = presentationData.scriptLevel;
 
-    nsCOMPtr<nsIStyleContext> oldStyleContext;
-    aFrame->GetStyleContext(getter_AddRefs(oldStyleContext));
-    nsCOMPtr<nsIStyleContext> parentContext(oldStyleContext->GetParent());
+    nsStyleContext* oldStyleContext = aFrame->GetStyleContext();
+    nsStyleContext* parentContext = oldStyleContext->GetParent();
 
     nsCOMPtr<nsIContent> content;
     aFrame->GetContent(getter_AddRefs(content));
@@ -730,11 +730,10 @@ nsMathMLContainerFrame::WrapForeignFrames(nsIPresContext* aPresContext)
       nsIFrame* wrapper;
       nsresult rv = NS_NewMathMLForeignFrameWrapper(shell, &wrapper);
       if (NS_FAILED(rv)) return rv;
-      nsCOMPtr<nsIStyleContext> newStyleContext;
-      aPresContext->ResolvePseudoStyleContextFor(mContent,
-                                                 nsCSSAnonBoxes::mozAnonymousBlock,
-                                                 mStyleContext,
-                                                 getter_AddRefs(newStyleContext));
+      nsRefPtr<nsStyleContext> newStyleContext;
+      newStyleContext = aPresContext->ResolvePseudoStyleContextFor(mContent,
+								   nsCSSAnonBoxes::mozAnonymousBlock,
+								   mStyleContext);
       rv = wrapper->Init(aPresContext, mContent, this, newStyleContext, nsnull);
       if (NS_FAILED(rv)) {
         wrapper->Destroy(aPresContext);
@@ -798,7 +797,7 @@ NS_IMETHODIMP
 nsMathMLContainerFrame::Init(nsIPresContext*  aPresContext,
                              nsIContent*      aContent,
                              nsIFrame*        aParent,
-                             nsIStyleContext* aContext,
+                             nsStyleContext*  aContext,
                              nsIFrame*        aPrevInFlow)
 {
   MapAttributesIntoCSS(aPresContext, aContent);
@@ -1446,8 +1445,7 @@ GetInterFrameSpacingFor(nsIPresContext* aPresContext,
       prevFrameType, childFrameType, &fromFrameType, &carrySpace);
     if (aChildFrame == childFrame) {
       // get thinspace
-      nsCOMPtr<nsIStyleContext> parentContext;
-      aParentFrame->GetStyleContext(getter_AddRefs(parentContext));
+      nsStyleContext* parentContext = aParentFrame->GetStyleContext();
       const nsStyleFont *font = NS_STATIC_CAST(const nsStyleFont*,
         parentContext->GetStyleData(eStyleStruct_Font));
       nscoord thinSpace = NSToCoordRound(float(font->mFont.size)*float(3) / float(18));
diff --git a/mozilla/layout/mathml/base/src/nsMathMLContainerFrame.h b/mozilla/layout/mathml/base/src/nsMathMLContainerFrame.h
index 30754fb25a2..d9f7e69b2b2 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLContainerFrame.h
+++ b/mozilla/layout/mathml/base/src/nsMathMLContainerFrame.h
@@ -110,7 +110,7 @@ public:
   Init(nsIPresContext*  aPresContext,
        nsIContent*      aContent,
        nsIFrame*        aParent,
-       nsIStyleContext* aContext,
+       nsStyleContext*  aContext,
        nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD
diff --git a/mozilla/layout/mathml/base/src/nsMathMLForeignFrameWrapper.cpp b/mozilla/layout/mathml/base/src/nsMathMLForeignFrameWrapper.cpp
index 8c3c6685393..808179161dd 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLForeignFrameWrapper.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLForeignFrameWrapper.cpp
@@ -33,7 +33,7 @@
 #include "nsIPresContext.h"
 #include "nsHTMLAtoms.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
@@ -63,7 +63,7 @@ NS_IMETHODIMP
 nsMathMLForeignFrameWrapper::Init(nsIPresContext*  aPresContext,
                                   nsIContent*      aContent,
                                   nsIFrame*        aParent,
-                                  nsIStyleContext* aContext,
+                                  nsStyleContext*  aContext,
                                   nsIFrame*        aPrevInFlow)
 {
   return nsBlockFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/mathml/base/src/nsMathMLForeignFrameWrapper.h b/mozilla/layout/mathml/base/src/nsMathMLForeignFrameWrapper.h
index 29fb4b8dda8..59dfc3d1572 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLForeignFrameWrapper.h
+++ b/mozilla/layout/mathml/base/src/nsMathMLForeignFrameWrapper.h
@@ -66,7 +66,7 @@ public:
   Init(nsIPresContext*  aPresContext,
        nsIContent*      aContent,
        nsIFrame*        aParent,
-       nsIStyleContext* aContext,
+       nsStyleContext*  aContext,
        nsIFrame*        aPrevInFlow);
 
 #ifdef NS_DEBUG
diff --git a/mozilla/layout/mathml/base/src/nsMathMLFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLFrame.cpp
index b6e492089d7..a7a10e91b2c 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLFrame.cpp
@@ -36,6 +36,7 @@
 #include "nsNetUtil.h"
 #include "nsIURI.h"
 #include "nsContentCID.h"
+#include "nsAutoPtr.h"
 static NS_DEFINE_CID(kCSSStyleSheetCID, NS_CSS_STYLESHEET_CID);
 
 
@@ -107,18 +108,17 @@ nsMathMLFrame::UpdatePresentationData(nsIPresContext* aPresContext,
 /* static */ void
 nsMathMLFrame::ResolveMathMLCharStyle(nsIPresContext*  aPresContext,
                                       nsIContent*      aContent,
-                                      nsIStyleContext* aParentStyleContext,
+                                      nsStyleContext*  aParentStyleContext,
                                       nsMathMLChar*    aMathMLChar,
                                       PRBool           aIsMutableChar)
 {
   nsIAtom* fontAtom = (aIsMutableChar) ?
     nsMathMLAtoms::fontstyle_stretchy :
     nsMathMLAtoms::fontstyle_anonymous; // savings
-  nsCOMPtr<nsIStyleContext> newStyleContext;
-  nsresult rv = aPresContext->ResolvePseudoStyleContextFor(aContent, fontAtom, 
-                                             aParentStyleContext,
-                                             getter_AddRefs(newStyleContext));
-  if (NS_SUCCEEDED(rv) && newStyleContext)
+  nsRefPtr<nsStyleContext> newStyleContext;
+  newStyleContext = aPresContext->ResolvePseudoStyleContextFor(aContent, fontAtom, 
+							       aParentStyleContext);
+  if (newStyleContext)
     aMathMLChar->SetStyleContext(newStyleContext);
 }
 
@@ -403,7 +403,7 @@ nsMathMLFrame::ParseNumericValue(nsString&   aString,
 
 /* static */ nscoord
 nsMathMLFrame::CalcLength(nsIPresContext*   aPresContext,
-                          nsIStyleContext*  aStyleContext,
+                          nsStyleContext*   aStyleContext,
                           const nsCSSValue& aCSSValue)
 {
   NS_ASSERTION(aCSSValue.IsLengthUnit(), "not a length unit");
diff --git a/mozilla/layout/mathml/base/src/nsMathMLFrame.h b/mozilla/layout/mathml/base/src/nsMathMLFrame.h
index 49504ebba48..9fcb4e6efe7 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLFrame.h
+++ b/mozilla/layout/mathml/base/src/nsMathMLFrame.h
@@ -26,7 +26,7 @@
 #include "nsIPresContext.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsMathMLAtoms.h"
 #include "nsMathMLOperators.h"
 #include "nsIMathMLFrame.h"
@@ -162,7 +162,7 @@ public:
   static void
   ResolveMathMLCharStyle(nsIPresContext*  aPresContext,
                          nsIContent*      aContent,
-                         nsIStyleContext* aParenStyleContext,
+                         nsStyleContext*  aParenStyleContext,
                          nsMathMLChar*    aMathMLChar,
                          PRBool           aIsMutableChar);
 
@@ -216,7 +216,7 @@ public:
 
   static nscoord 
   CalcLength(nsIPresContext*   aPresContext,
-             nsIStyleContext*  aStyleContext,
+             nsStyleContext*   aStyleContext,
              const nsCSSValue& aCSSValue);
 
   static PRBool
diff --git a/mozilla/layout/mathml/base/src/nsMathMLTokenFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLTokenFrame.cpp
index fbea576a9b8..5e60a0befaf 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLTokenFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLTokenFrame.cpp
@@ -23,7 +23,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
@@ -95,7 +95,7 @@ NS_IMETHODIMP
 nsMathMLTokenFrame::Init(nsIPresContext*  aPresContext,
                          nsIContent*      aContent,
                          nsIFrame*        aParent,
-                         nsIStyleContext* aContext,
+                         nsStyleContext*  aContext,
                          nsIFrame*        aPrevInFlow)
 {
   // leading and trailing whitespace doesn't count -- bug 15402
diff --git a/mozilla/layout/mathml/base/src/nsMathMLTokenFrame.h b/mozilla/layout/mathml/base/src/nsMathMLTokenFrame.h
index cd90f2cfd7b..da0501f9dd3 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLTokenFrame.h
+++ b/mozilla/layout/mathml/base/src/nsMathMLTokenFrame.h
@@ -40,7 +40,7 @@ public:
   Init(nsIPresContext*  aPresContext,
        nsIContent*      aContent,
        nsIFrame*        aParent,
-       nsIStyleContext* aContext,
+       nsStyleContext*  aContext,
        nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmactionFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmactionFrame.cpp
index 55fb9cbb3bb..039c2521499 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmactionFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmactionFrame.cpp
@@ -23,7 +23,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsINameSpaceManager.h"
 #include "nsIRenderingContext.h"
@@ -44,6 +44,7 @@
 #include "nsIDOMMouseListener.h"
 
 #include "nsMathMLmactionFrame.h"
+#include "nsAutoPtr.h"
 
 //
 // <maction> -- bind actions to a subexpression - implementation
@@ -90,7 +91,7 @@ NS_IMETHODIMP
 nsMathMLmactionFrame::Init(nsIPresContext*  aPresContext,
                            nsIContent*      aContent,
                            nsIFrame*        aParent,
-                           nsIStyleContext* aContext,
+                           nsStyleContext*  aContext,
                            nsIFrame*        aPrevInFlow)
 {
   nsAutoString value, prefix;
@@ -103,6 +104,7 @@ nsMathMLmactionFrame::Init(nsIPresContext*  aPresContext,
   mChildCount = -1; // these will be updated in GetSelectedFrame()
   mSelection = 0;
   mSelectedFrame = nsnull;
+  nsRefPtr<nsStyleContext> newStyleContext;
 
   mActionType = NS_MATHML_ACTION_TYPE_NONE;
   if (NS_CONTENT_ATTR_HAS_VALUE == aContent->GetAttr(kNameSpaceID_None, 
@@ -139,20 +141,16 @@ nsMathMLmactionFrame::Init(nsIPresContext*  aPresContext,
         aContent->UnsetAttr(kNameSpaceID_None, nsMathMLAtoms::actiontype_, notify);
 
         // then, re-resolve our style
-        nsCOMPtr<nsIStyleContext> parentStyleContext;
-        aParent->GetStyleContext(getter_AddRefs(parentStyleContext));
-        nsIStyleContext* newStyleContext;
-        aPresContext->ResolveStyleContextFor(aContent, parentStyleContext,
-                                             &newStyleContext);
+        nsStyleContext* parentStyleContext = aParent->GetStyleContext();
+        newStyleContext = aPresContext->ResolveStyleContextFor(aContent,
+							       parentStyleContext);
         if (!newStyleContext) 
           mRestyle.Truncate();
         else {
           if (newStyleContext != aContext)
             aContext = newStyleContext;
-          else {
-            NS_RELEASE(newStyleContext);
+          else
             mRestyle.Truncate();
-          }
         }
       }
     }
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmactionFrame.h b/mozilla/layout/mathml/base/src/nsMathMLmactionFrame.h
index 81cc167cca5..70fade01e76 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmactionFrame.h
+++ b/mozilla/layout/mathml/base/src/nsMathMLmactionFrame.h
@@ -48,7 +48,7 @@ public:
   Init(nsIPresContext*  aPresContext,
        nsIContent*      aContent,
        nsIFrame*        aParent,
-       nsIStyleContext* aContext,
+       nsStyleContext*  aContext,
        nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmfencedFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmfencedFrame.cpp
index 543b5de754d..64b7090e4f1 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmfencedFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmfencedFrame.cpp
@@ -26,7 +26,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
@@ -584,11 +584,9 @@ nsMathMLmfencedFrame::PlaceChar(nsMathMLChar*      aMathMLChar,
 
 // ----------------------
 // the Style System will use these to pass the proper style context to our MathMLChar
-NS_IMETHODIMP
-nsMathMLmfencedFrame::GetAdditionalStyleContext(PRInt32           aIndex, 
-                                                nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsMathMLmfencedFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
 {
-  NS_PRECONDITION(aStyleContext, "null OUT ptr");
   PRInt32 openIndex = -1;
   PRInt32 closeIndex = -1;
   PRInt32 lastIndex = mSeparatorsCount-1;
@@ -602,25 +600,24 @@ nsMathMLmfencedFrame::GetAdditionalStyleContext(PRInt32           aIndex,
     closeIndex = lastIndex;
   }
   if (aIndex < 0 || aIndex > lastIndex) {
-    return NS_ERROR_INVALID_ARG;
+    return nsnull;
   }
 
-  *aStyleContext = nsnull;
   if (aIndex < mSeparatorsCount) {
-    mSeparatorsChar[aIndex].GetStyleContext(aStyleContext);
+    return mSeparatorsChar[aIndex].GetStyleContext();
   }
   else if (aIndex == openIndex) {
-    mOpenChar->GetStyleContext(aStyleContext);
+    return mOpenChar->GetStyleContext();
   }
   else if (aIndex == closeIndex) {
-    mCloseChar->GetStyleContext(aStyleContext);
+    return mCloseChar->GetStyleContext();
   }
-  return NS_OK;
+  return nsnull;
 }
 
-NS_IMETHODIMP
+void
 nsMathMLmfencedFrame::SetAdditionalStyleContext(PRInt32          aIndex, 
-                                                nsIStyleContext* aStyleContext)
+                                                nsStyleContext*  aStyleContext)
 {
   PRInt32 openIndex = -1;
   PRInt32 closeIndex = -1;
@@ -635,7 +632,7 @@ nsMathMLmfencedFrame::SetAdditionalStyleContext(PRInt32          aIndex,
     closeIndex = lastIndex;
   }
   if (aIndex < 0 || aIndex > lastIndex) {
-    return NS_ERROR_INVALID_ARG;
+    return;
   }
 
   if (aIndex < mSeparatorsCount) {
@@ -647,5 +644,4 @@ nsMathMLmfencedFrame::SetAdditionalStyleContext(PRInt32          aIndex,
   else if (aIndex == closeIndex) {
     mCloseChar->SetStyleContext(aStyleContext);
   }
-  return NS_OK;
 }
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmfencedFrame.h b/mozilla/layout/mathml/base/src/nsMathMLmfencedFrame.h
index 71b221ad5b3..27383263031 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmfencedFrame.h
+++ b/mozilla/layout/mathml/base/src/nsMathMLmfencedFrame.h
@@ -34,12 +34,11 @@ class nsMathMLmfencedFrame : public nsMathMLContainerFrame {
 public:
   friend nsresult NS_NewMathMLmfencedFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame);
 
-  NS_IMETHOD
+  virtual void
   SetAdditionalStyleContext(PRInt32          aIndex, 
-                            nsIStyleContext* aStyleContext);
-  NS_IMETHOD
-  GetAdditionalStyleContext(PRInt32           aIndex, 
-                            nsIStyleContext** aStyleContext) const;
+                            nsStyleContext*  aStyleContext);
+  virtual nsStyleContext*
+  GetAdditionalStyleContext(PRInt32 aIndex) const;
 
   NS_IMETHOD
   InheritAutomaticData(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmfracFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmfracFrame.cpp
index de132a3eb97..5e17881a191 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmfracFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmfracFrame.cpp
@@ -26,7 +26,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
@@ -99,7 +99,7 @@ NS_IMETHODIMP
 nsMathMLmfracFrame::Init(nsIPresContext*  aPresContext,
                          nsIContent*      aContent,
                          nsIFrame*        aParent,
-                         nsIStyleContext* aContext,
+                         nsStyleContext*  aContext,
                          nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsMathMLContainerFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
@@ -152,7 +152,7 @@ nsMathMLmfracFrame::TransmitAutomaticData(nsIPresContext* aPresContext)
 
 nscoord 
 nsMathMLmfracFrame::CalcLineThickness(nsIPresContext*  aPresContext,
-                                      nsIStyleContext* aStyleContext,
+                                      nsStyleContext*  aStyleContext,
                                       nsString&        aThicknessAttribute,
                                       nscoord          onePixel,
                                       nscoord          aDefaultRuleThickness)
@@ -548,36 +548,31 @@ nsMathMLmfracFrame::UpdatePresentationDataFromChildAt(nsIPresContext* aPresConte
 
 // ----------------------
 // the Style System will use these to pass the proper style context to our MathMLChar
-NS_IMETHODIMP
-nsMathMLmfracFrame::GetAdditionalStyleContext(PRInt32           aIndex, 
-                                              nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsMathMLmfracFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
 {
-  NS_PRECONDITION(aStyleContext, "null OUT ptr");
-  if (!mSlashChar || aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
+  if (!mSlashChar) {
+    return nsnull;
   }
-  *aStyleContext = nsnull;
   switch (aIndex) {
   case NS_SLASH_CHAR_STYLE_CONTEXT_INDEX:
-    mSlashChar->GetStyleContext(aStyleContext);
+    return mSlashChar->GetStyleContext();
     break;
   default:
-    return NS_ERROR_INVALID_ARG;
+    return nsnull;
   }
-  return NS_OK;
 }
 
-NS_IMETHODIMP
+void
 nsMathMLmfracFrame::SetAdditionalStyleContext(PRInt32          aIndex, 
-                                              nsIStyleContext* aStyleContext)
+                                              nsStyleContext*  aStyleContext)
 {
-  if (!mSlashChar || aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
+  if (!mSlashChar) {
+    return;
   }
   switch (aIndex) {
   case NS_SLASH_CHAR_STYLE_CONTEXT_INDEX:
     mSlashChar->SetStyleContext(aStyleContext);
     break;
   }
-  return NS_OK;
 }
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmfracFrame.h b/mozilla/layout/mathml/base/src/nsMathMLmfracFrame.h
index 0eecfcfdc3e..ebfe0653bae 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmfracFrame.h
+++ b/mozilla/layout/mathml/base/src/nsMathMLmfracFrame.h
@@ -71,12 +71,11 @@ class nsMathMLmfracFrame : public nsMathMLContainerFrame {
 public:
   friend nsresult NS_NewMathMLmfracFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame);
 
-  NS_IMETHOD
+  virtual void
   SetAdditionalStyleContext(PRInt32          aIndex, 
-                            nsIStyleContext* aStyleContext);
-  NS_IMETHOD
-  GetAdditionalStyleContext(PRInt32           aIndex, 
-                            nsIStyleContext** aStyleContext) const;
+                            nsStyleContext*  aStyleContext);
+  virtual nsStyleContext*
+  GetAdditionalStyleContext(PRInt32 aIndex) const;
 
   NS_IMETHOD
   AttributeChanged(nsIPresContext* aPresContext,
@@ -90,7 +89,7 @@ public:
   Init(nsIPresContext*  aPresContext,
        nsIContent*      aContent,
        nsIFrame*        aParent,
-       nsIStyleContext* aContext,
+       nsStyleContext*  aContext,
        nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD
@@ -132,7 +131,7 @@ public:
   // helper to translate the thickness attribute into a usable form
   static nscoord 
   CalcLineThickness(nsIPresContext*  aPresContext,
-                    nsIStyleContext* aStyleContext,
+                    nsStyleContext*  aStyleContext,
                     nsString&        aThicknessAttribute,
                     nscoord          onePixel,
                     nscoord          aDefaultRuleThickness);
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmmultiscriptsFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmmultiscriptsFrame.cpp
index 5927339b12f..75ea057abdb 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmmultiscriptsFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmmultiscriptsFrame.cpp
@@ -26,7 +26,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmoFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmoFrame.cpp
index 1812f9bafe8..c9bd3275792 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmoFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmoFrame.cpp
@@ -26,7 +26,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
@@ -1028,36 +1028,24 @@ nsMathMLmoFrame::AttributeChanged(nsIPresContext* aPresContext,
 // ----------------------
 // No need to tract the style context given to our MathML char. 
 // the Style System will use these to pass the proper style context to our MathMLChar
-NS_IMETHODIMP
-nsMathMLmoFrame::GetAdditionalStyleContext(PRInt32           aIndex,
-                                           nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsMathMLmoFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
 {
-  NS_PRECONDITION(aStyleContext, "null OUT ptr");
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
-  *aStyleContext = nsnull;
   switch (aIndex) {
   case NS_MATHML_CHAR_STYLE_CONTEXT_INDEX:
-    mMathMLChar.GetStyleContext(aStyleContext);
-    break;
+    return mMathMLChar.GetStyleContext();
   default:
-    return NS_ERROR_INVALID_ARG;
+    return nsnull;
   }
-  return NS_OK;
 }
 
-NS_IMETHODIMP
+void
 nsMathMLmoFrame::SetAdditionalStyleContext(PRInt32          aIndex,
-                                           nsIStyleContext* aStyleContext)
+                                           nsStyleContext*  aStyleContext)
 {
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
   switch (aIndex) {
   case NS_MATHML_CHAR_STYLE_CONTEXT_INDEX:
     mMathMLChar.SetStyleContext(aStyleContext);
     break;
   }
-  return NS_OK;
 }
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmoFrame.h b/mozilla/layout/mathml/base/src/nsMathMLmoFrame.h
index c1d7e4dd246..1ddbf1d70f8 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmoFrame.h
+++ b/mozilla/layout/mathml/base/src/nsMathMLmoFrame.h
@@ -38,12 +38,11 @@ public:
   NS_IMETHOD
   GetFrameType(nsIAtom** aType) const;
 
-  NS_IMETHOD
+  virtual void
   SetAdditionalStyleContext(PRInt32          aIndex, 
-                            nsIStyleContext* aStyleContext);
-  NS_IMETHOD
-  GetAdditionalStyleContext(PRInt32           aIndex, 
-                            nsIStyleContext** aStyleContext) const;
+                            nsStyleContext*  aStyleContext);
+  virtual nsStyleContext*
+  GetAdditionalStyleContext(PRInt32 aIndex) const;
 
   NS_IMETHOD
   Paint(nsIPresContext*      aPresContext,
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmoverFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmoverFrame.cpp
index 2b86d719b36..eb8d20a1503 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmoverFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmoverFrame.cpp
@@ -27,7 +27,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsINameSpaceManager.h"
 #include "nsIRenderingContext.h"
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmpaddedFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmpaddedFrame.cpp
index b9e8cc739ed..8e6ff575a1b 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmpaddedFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmpaddedFrame.cpp
@@ -25,7 +25,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
@@ -293,7 +293,7 @@ nsMathMLmpaddedFrame::ParseAttribute(nsString&   aString,
 
 void
 nsMathMLmpaddedFrame::UpdateValue(nsIPresContext*      aPresContext,
-                                  nsIStyleContext*     aStyleContext,
+                                  nsStyleContext*      aStyleContext,
                                   PRInt32              aSign,
                                   PRInt32              aPseudoUnit,
                                   nsCSSValue&          aCSSValue,
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmpaddedFrame.h b/mozilla/layout/mathml/base/src/nsMathMLmpaddedFrame.h
index f61c554b633..8416202c7ae 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmpaddedFrame.h
+++ b/mozilla/layout/mathml/base/src/nsMathMLmpaddedFrame.h
@@ -78,7 +78,7 @@ private:
 
   static void
   UpdateValue(nsIPresContext*      aPresContext,
-              nsIStyleContext*     aStyleContext,
+              nsStyleContext*      aStyleContext,
               PRInt32              aSign,
               PRInt32              aPseudoUnit,
               nsCSSValue&          aCSSValue,
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmrootFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmrootFrame.cpp
index 51469f4cacc..bbef79a6a59 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmrootFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmrootFrame.cpp
@@ -27,7 +27,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
@@ -81,7 +81,7 @@ NS_IMETHODIMP
 nsMathMLmrootFrame::Init(nsIPresContext*  aPresContext,
                          nsIContent*      aContent,
                          nsIFrame*        aParent,
-                         nsIStyleContext* aContext,
+                         nsStyleContext*  aContext,
                          nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsMathMLContainerFrame::Init(aPresContext, aContent, aParent,
@@ -378,36 +378,25 @@ nsMathMLmrootFrame::Reflow(nsIPresContext*          aPresContext,
 
 // ----------------------
 // the Style System will use these to pass the proper style context to our MathMLChar
-NS_IMETHODIMP
-nsMathMLmrootFrame::GetAdditionalStyleContext(PRInt32           aIndex, 
-                                              nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsMathMLmrootFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
 {
-  NS_PRECONDITION(aStyleContext, "null OUT ptr");
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
-  *aStyleContext = nsnull;
   switch (aIndex) {
   case NS_SQR_CHAR_STYLE_CONTEXT_INDEX:
-    mSqrChar.GetStyleContext(aStyleContext);
+    return mSqrChar.GetStyleContext();
     break;
   default:
-    return NS_ERROR_INVALID_ARG;
+    return nsnull;
   }
-  return NS_OK;
 }
 
-NS_IMETHODIMP
+void
 nsMathMLmrootFrame::SetAdditionalStyleContext(PRInt32          aIndex, 
-                                              nsIStyleContext* aStyleContext)
+                                              nsStyleContext*  aStyleContext)
 {
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
   switch (aIndex) {
   case NS_SQR_CHAR_STYLE_CONTEXT_INDEX:
     mSqrChar.SetStyleContext(aStyleContext);
     break;
   }
-  return NS_OK;
 }
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmrootFrame.h b/mozilla/layout/mathml/base/src/nsMathMLmrootFrame.h
index abd1241f790..45a6e3bd522 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmrootFrame.h
+++ b/mozilla/layout/mathml/base/src/nsMathMLmrootFrame.h
@@ -35,18 +35,17 @@ class nsMathMLmrootFrame : public nsMathMLContainerFrame {
 public:
   friend nsresult NS_NewMathMLmrootFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame);
 
-  NS_IMETHOD
+  virtual void
   SetAdditionalStyleContext(PRInt32          aIndex, 
-                            nsIStyleContext* aStyleContext);
-  NS_IMETHOD
-  GetAdditionalStyleContext(PRInt32           aIndex, 
-                            nsIStyleContext** aStyleContext) const;
+                            nsStyleContext*  aStyleContext);
+  virtual nsStyleContext*
+  GetAdditionalStyleContext(PRInt32 aIndex) const;
 
   NS_IMETHOD
   Init(nsIPresContext*  aPresContext,
        nsIContent*      aContent,
        nsIFrame*        aParent,
-       nsIStyleContext* aContext,
+       nsStyleContext*  aContext,
        nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmrowFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmrowFrame.cpp
index 58d44bae216..f8fc1801ad6 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmrowFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmrowFrame.cpp
@@ -25,7 +25,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmspaceFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmspaceFrame.cpp
index 8d1338a7d37..d99bafe18a1 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmspaceFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmspaceFrame.cpp
@@ -24,7 +24,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmsqrtFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmsqrtFrame.cpp
index c08307abe56..bddfa4ea8fe 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmsqrtFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmsqrtFrame.cpp
@@ -27,7 +27,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
@@ -81,7 +81,7 @@ NS_IMETHODIMP
 nsMathMLmsqrtFrame::Init(nsIPresContext*  aPresContext,
                          nsIContent*      aContent,
                          nsIFrame*        aParent,
-                         nsIStyleContext* aContext,
+                         nsStyleContext*  aContext,
                          nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsMathMLContainerFrame::Init(aPresContext, aContent, aParent,
@@ -297,36 +297,25 @@ nsMathMLmsqrtFrame::Reflow(nsIPresContext*          aPresContext,
 
 // ----------------------
 // the Style System will use these to pass the proper style context to our MathMLChar
-NS_IMETHODIMP
-nsMathMLmsqrtFrame::GetAdditionalStyleContext(PRInt32           aIndex, 
-                                              nsIStyleContext** aStyleContext) const
+nsStyleContext*
+nsMathMLmsqrtFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
 {
-  NS_PRECONDITION(aStyleContext, "null OUT ptr");
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
-  *aStyleContext = nsnull;
   switch (aIndex) {
   case NS_SQR_CHAR_STYLE_CONTEXT_INDEX:
-    mSqrChar.GetStyleContext(aStyleContext);
+    return mSqrChar.GetStyleContext();
     break;
   default:
-    return NS_ERROR_INVALID_ARG;
+    return nsnull;
   }
-  return NS_OK;
 }
 
-NS_IMETHODIMP
+void
 nsMathMLmsqrtFrame::SetAdditionalStyleContext(PRInt32          aIndex, 
-                                              nsIStyleContext* aStyleContext)
+                                              nsStyleContext*  aStyleContext)
 {
-  if (aIndex < 0) {
-    return NS_ERROR_INVALID_ARG;
-  }
   switch (aIndex) {
   case NS_SQR_CHAR_STYLE_CONTEXT_INDEX:
     mSqrChar.SetStyleContext(aStyleContext);
     break;
   }
-  return NS_OK;
 }
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmsqrtFrame.h b/mozilla/layout/mathml/base/src/nsMathMLmsqrtFrame.h
index 1592d0ce1ba..29f384f3979 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmsqrtFrame.h
+++ b/mozilla/layout/mathml/base/src/nsMathMLmsqrtFrame.h
@@ -59,18 +59,17 @@ class nsMathMLmsqrtFrame : public nsMathMLContainerFrame {
 public:
   friend nsresult NS_NewMathMLmsqrtFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame);
 
-  NS_IMETHOD
+  virtual void
   SetAdditionalStyleContext(PRInt32          aIndex, 
-                            nsIStyleContext* aStyleContext);
-  NS_IMETHOD
-  GetAdditionalStyleContext(PRInt32           aIndex, 
-                            nsIStyleContext** aStyleContext) const;
+                            nsStyleContext*  aStyleContext);
+  virtual nsStyleContext*
+  GetAdditionalStyleContext(PRInt32 aIndex) const;
 
   NS_IMETHOD
   Init(nsIPresContext*  aPresContext,
        nsIContent*      aContent,
        nsIFrame*        aParent,
-       nsIStyleContext* aContext,
+       nsStyleContext*  aContext,
        nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmstyleFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmstyleFrame.cpp
index 3f7d1321cf0..4054e2bd94d 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmstyleFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmstyleFrame.cpp
@@ -25,7 +25,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsINameSpaceManager.h"
 #include "nsIRenderingContext.h"
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmsubFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmsubFrame.cpp
index ff80bc2e860..9fd242756d7 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmsubFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmsubFrame.cpp
@@ -26,7 +26,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmsubsupFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmsubsupFrame.cpp
index 6acfeb5ecc4..6bd0bf4b102 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmsubsupFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmsubsupFrame.cpp
@@ -26,7 +26,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmsupFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmsupFrame.cpp
index c2dcf62faa6..6d65a95eaa8 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmsupFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmsupFrame.cpp
@@ -25,7 +25,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIRenderingContext.h"
 #include "nsIFontMetrics.h"
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmtableFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmtableFrame.cpp
index 8d5265fc723..9418c611d10 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmtableFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmtableFrame.cpp
@@ -24,7 +24,7 @@
 #include "nsAreaFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsINameSpaceManager.h"
 #include "nsIRenderingContext.h"
@@ -420,7 +420,7 @@ NS_IMETHODIMP
 nsMathMLmtableOuterFrame::Init(nsIPresContext*  aPresContext,
                                nsIContent*      aContent,
                                nsIFrame*        aParent,
-                               nsIStyleContext* aContext,
+                               nsStyleContext*  aContext,
                                nsIFrame*        aPrevInFlow)
 {
   MapAttributesIntoCSS(aPresContext, aContent);
@@ -691,7 +691,7 @@ NS_IMETHODIMP
 nsMathMLmtdInnerFrame::Init(nsIPresContext*  aPresContext,
                             nsIContent*      aContent,
                             nsIFrame*        aParent,
-                            nsIStyleContext* aContext,
+                            nsStyleContext*  aContext,
                             nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsBlockFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmtableFrame.h b/mozilla/layout/mathml/base/src/nsMathMLmtableFrame.h
index d40cd31fd0f..7c7dea4f5b6 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmtableFrame.h
+++ b/mozilla/layout/mathml/base/src/nsMathMLmtableFrame.h
@@ -70,7 +70,7 @@ public:
   Init(nsIPresContext*  aPresContext,
        nsIContent*      aContent,
        nsIFrame*        aParent,
-       nsIStyleContext* aContext,
+       nsStyleContext*  aContext,
        nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD
@@ -147,7 +147,7 @@ public:
   Init(nsIPresContext*  aPresContext,
        nsIContent*      aContent,
        nsIFrame*        aParent,
-       nsIStyleContext* aContext,
+       nsStyleContext*  aContext,
        nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmunderFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmunderFrame.cpp
index 687a2cca9f7..03ee58625dd 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmunderFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmunderFrame.cpp
@@ -27,7 +27,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsINameSpaceManager.h"
 #include "nsIRenderingContext.h"
diff --git a/mozilla/layout/mathml/base/src/nsMathMLmunderoverFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLmunderoverFrame.cpp
index 1d8638a40ac..0ed60ed23f3 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLmunderoverFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLmunderoverFrame.cpp
@@ -27,7 +27,7 @@
 #include "nsFrame.h"
 #include "nsIPresContext.h"
 #include "nsUnitConversion.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsINameSpaceManager.h"
 #include "nsIRenderingContext.h"
diff --git a/mozilla/layout/printing/nsPrintEngine.cpp b/mozilla/layout/printing/nsPrintEngine.cpp
index 39d8afbec3b..5655bfd8e0e 100644
--- a/mozilla/layout/printing/nsPrintEngine.cpp
+++ b/mozilla/layout/printing/nsPrintEngine.cpp
@@ -2585,13 +2585,10 @@ nsPrintEngine::ReflowDocList(nsPrintObject* aPO, PRBool aSetPixelScale, PRBool a
     nsIFrame * frame;
     aPO->mParent->mPresShell->GetPrimaryFrameFor(aPO->mContent, &frame);
     if (frame) {
-      nsCOMPtr<nsIStyleContext> sc;
-      frame->GetStyleContext(getter_AddRefs(sc));
-      if (sc) {
-        const nsStyleVisibility* vis = (const nsStyleVisibility*)sc->GetStyleData(eStyleStruct_Visibility);
-        if (!vis->IsVisible()) {
-          aPO->mDontPrint = PR_TRUE;
-        }
+      const nsStyleVisibility* vis;
+      ::GetStyleData(frame, &vis);
+      if (!vis->IsVisible()) {
+        aPO->mDontPrint = PR_TRUE;
       }
     }
   }
diff --git a/mozilla/layout/style/nsCSSStyleRule.cpp b/mozilla/layout/style/nsCSSStyleRule.cpp
index 88d21e667f1..3795eb52a37 100644
--- a/mozilla/layout/style/nsCSSStyleRule.cpp
+++ b/mozilla/layout/style/nsCSSStyleRule.cpp
@@ -73,6 +73,7 @@
 #include "nsISizeOfHandler.h"
 
 #include "nsContentUtils.h"
+#include "nsContentErrors.h"
 
 // #define DEBUG_REFS
  
diff --git a/mozilla/layout/style/nsComputedDOMStyle.cpp b/mozilla/layout/style/nsComputedDOMStyle.cpp
index 9c5cf771a27..685367036d5 100644
--- a/mozilla/layout/style/nsComputedDOMStyle.cpp
+++ b/mozilla/layout/style/nsComputedDOMStyle.cpp
@@ -44,7 +44,7 @@
 #include "nsDOMError.h"
 #include "nsIDOMCSS2Properties.h"
 #include "nsIDOMElement.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIScrollableFrame.h"
 #include "nsContentUtils.h"
 #include "prprf.h"
@@ -3034,18 +3034,16 @@ nsComputedDOMStyle::GetStyleData(nsStyleStructID aID,
     nsCOMPtr<nsIPresContext> pctx;
     presShell->GetPresContext(getter_AddRefs(pctx));
     if (pctx) {
-      nsCOMPtr<nsIStyleContext> sctx;
+      nsStyleContext* sctx;
       if (!mPseudo) {
-        pctx->ResolveStyleContextFor(mContent, nsnull,
-                                     getter_AddRefs(sctx));
+        sctx = pctx->ResolveStyleContextFor(mContent, nsnull).get();
       } else {
-        pctx->ResolvePseudoStyleContextFor(mContent, mPseudo, nsnull,
-                                           getter_AddRefs(sctx));
+        sctx = pctx->ResolvePseudoStyleContextFor(mContent, mPseudo, nsnull).get();
       }
       if (sctx) {
         aStyleStruct = sctx->GetStyleData(aID);
       }
-      mStyleContextHolder = sctx;
+      mStyleContextHolder = dont_AddRef(sctx);  // transfer ref from sctx
     }
   }
   NS_ASSERTION(aStyleStruct, "Failed to get a style struct");
diff --git a/mozilla/layout/style/nsComputedDOMStyle.h b/mozilla/layout/style/nsComputedDOMStyle.h
index cdcd52b9dd3..e51d29ee2f4 100644
--- a/mozilla/layout/style/nsComputedDOMStyle.h
+++ b/mozilla/layout/style/nsComputedDOMStyle.h
@@ -53,6 +53,7 @@
 #include "nsIFrame.h"
 #include "nsCOMPtr.h"
 #include "nsWeakReference.h"
+#include "nsAutoPtr.h"
 
 class nsComputedDOMStyle : public nsIComputedDOMStyle
 {
@@ -302,7 +303,7 @@ private:
    * When a frame is unavailable, strong reference to the
    * style context while we're accessing the data from in.
    */
-  nsCOMPtr<nsIStyleContext> mStyleContextHolder;
+  nsRefPtr<nsStyleContext> mStyleContextHolder;
   nsCOMPtr<nsIAtom> mPseudo;
 
   float mT2P; /* For unit conversions */
diff --git a/mozilla/layout/style/nsHTMLStyleSheet.cpp b/mozilla/layout/style/nsHTMLStyleSheet.cpp
index 9400f2caa72..bd1ff22e153 100644
--- a/mozilla/layout/style/nsHTMLStyleSheet.cpp
+++ b/mozilla/layout/style/nsHTMLStyleSheet.cpp
@@ -42,7 +42,7 @@
 #include "nsIStyleRuleProcessor.h"
 #include "nsIStyleRule.h"
 #include "nsIFrame.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsHTMLAtoms.h"
 #include "nsIPresContext.h"
 #include "nsIEventStateManager.h"
@@ -393,7 +393,7 @@ static void PostResolveCallback(nsStyleStruct* aStyleStruct, nsRuleData* aRuleDa
 {
   nsStyleText* text = (nsStyleText*)aStyleStruct;
   if (text->mTextAlign == NS_STYLE_TEXT_ALIGN_DEFAULT) {
-    nsCOMPtr<nsIStyleContext> parentContext = aRuleData->mStyleContext->GetParent();
+    nsStyleContext* parentContext = aRuleData->mStyleContext->GetParent();
 
     if (parentContext) {
       const nsStyleText* parentStyleText = 
@@ -426,7 +426,7 @@ ProcessTableRulesAttribute(nsStyleStruct* aStyleStruct,
 {
   if (!aStyleStruct || !aRuleData || !aRuleData->mPresContext) return;
 
-  nsCOMPtr<nsIStyleContext> tableContext = aRuleData->mStyleContext->GetParent();
+  nsStyleContext* tableContext = aRuleData->mStyleContext->GetParent();
   if (!tableContext)
     return;
   if (!aGroup) {
diff --git a/mozilla/layout/style/nsIStyleRuleProcessor.h b/mozilla/layout/style/nsIStyleRuleProcessor.h
index 78f2f2ab24d..ac4a7517775 100644
--- a/mozilla/layout/style/nsIStyleRuleProcessor.h
+++ b/mozilla/layout/style/nsIStyleRuleProcessor.h
@@ -48,7 +48,6 @@
 class nsISizeOfHandler;
 
 class nsIStyleSheet;
-class nsIStyleContext;
 class nsIPresContext;
 class nsIContent;
 class nsIStyledContent;
diff --git a/mozilla/layout/style/nsIStyleSheet.h b/mozilla/layout/style/nsIStyleSheet.h
index a31423ebc5c..9e830d71dd3 100644
--- a/mozilla/layout/style/nsIStyleSheet.h
+++ b/mozilla/layout/style/nsIStyleSheet.h
@@ -51,7 +51,6 @@ class nsISupportsArray;
 class nsIPresContext;
 class nsIContent;
 class nsIDocument;
-class nsIStyleContext;
 class nsIStyleRuleProcessor;
 
 // IID for the nsIStyleSheet interface {8c4a80a0-ad6a-11d1-8031-006008159b5a}
diff --git a/mozilla/layout/style/nsInspectorCSSUtils.cpp b/mozilla/layout/style/nsInspectorCSSUtils.cpp
index 9d073a32cd3..b327a0ab4b5 100644
--- a/mozilla/layout/style/nsInspectorCSSUtils.cpp
+++ b/mozilla/layout/style/nsInspectorCSSUtils.cpp
@@ -43,6 +43,8 @@
 #include "nsLayoutAtoms.h"
 #include "nsIDocument.h"
 #include "nsIPresShell.h"
+#include "nsAutoPtr.h"
+#include "nsIFrame.h"
 
 nsInspectorCSSUtils::nsInspectorCSSUtils()
 {
@@ -113,18 +115,12 @@ nsInspectorCSSUtils::AdjustRectForMargins(nsIFrame* aFrame, nsRect& aRect)
   return NS_OK;
 }
 
-nsresult
-nsInspectorCSSUtils::GetStyleContextForFrame(nsIFrame* aFrame,
-                                             nsIStyleContext** aStyleContext)
+nsStyleContext*
+nsInspectorCSSUtils::GetStyleContextForFrame(nsIFrame* aFrame)
 {
-    nsCOMPtr<nsIStyleContext> styleContext;
-    aFrame->GetStyleContext(getter_AddRefs(styleContext));
-    if (!styleContext) {
-        // Caller returns rv on through, and this does not seem
-        // exception-worthy.
-        *aStyleContext = nsnull;
-        return NS_OK;
-    }
+    nsStyleContext* styleContext = aFrame->GetStyleContext();
+    if (!styleContext)
+        return nsnull;
 
     /* For tables the primary frame is the "outer frame" but the style
      * rules are applied to the "inner frame".  Luckily, the "outer
@@ -133,45 +129,42 @@ nsInspectorCSSUtils::GetStyleContextForFrame(nsIFrame* aFrame,
      */
     nsCOMPtr<nsIAtom> frameType;
     aFrame->GetFrameType(getter_AddRefs(frameType));
-    if (frameType == nsLayoutAtoms::tableOuterFrame) {
-        *aStyleContext = styleContext->GetParent().get();
-    } else {
-        *aStyleContext = styleContext;
-        NS_ADDREF(*aStyleContext);
-    }
-    return NS_OK;
+    if (frameType == nsLayoutAtoms::tableOuterFrame)
+        return styleContext->GetParent();
+
+    return styleContext;
 }    
 
-nsresult
+already_AddRefed<nsStyleContext>
 nsInspectorCSSUtils::GetStyleContextForContent(nsIContent* aContent,
-                                               nsIPresShell* aPresShell,
-                                               nsIStyleContext** aStyleContext)
+                                               nsIPresShell* aPresShell)
 {
     nsIFrame* frame = nsnull;
     aPresShell->GetPrimaryFrameFor(aContent, &frame);
-    if (frame)
-        return GetStyleContextForFrame(frame, aStyleContext);
+    if (frame) {
+        nsStyleContext* result = GetStyleContextForFrame(frame);
+        // this function returns an addrefed style context
+        if (result)
+            result->AddRef();
+        return result;
+    }
 
     // No frame has been created, so resolve the style ourselves
-    nsCOMPtr<nsIStyleContext> parentContext;
+    nsRefPtr<nsStyleContext> parentContext;
     nsCOMPtr<nsIContent> parent;
     aContent->GetParent(*getter_AddRefs(parent));
-    if (parent) {
-        nsresult rv = GetStyleContextForContent(parent, aPresShell,
-                                                getter_AddRefs(parentContext));
-        NS_ENSURE_SUCCESS(rv, rv);
-    }
+    if (parent)
+        parentContext = GetStyleContextForContent(parent, aPresShell);
 
     nsCOMPtr<nsIPresContext> presContext;
     aPresShell->GetPresContext(getter_AddRefs(presContext));
-    NS_ENSURE_TRUE(presContext, NS_ERROR_UNEXPECTED);
+    if (!presContext)
+        return nsnull;
 
     if (aContent->IsContentOfType(nsIContent::eELEMENT))
-        return presContext->ResolveStyleContextFor(aContent, parentContext,
-                                                   aStyleContext);
+        return presContext->ResolveStyleContextFor(aContent, parentContext);
 
-    return presContext->ResolveStyleContextForNonElement(parentContext,
-                                                         aStyleContext);
+    return presContext->ResolveStyleContextForNonElement(parentContext);
 }
 
 NS_IMETHODIMP
@@ -188,10 +181,7 @@ nsInspectorCSSUtils::GetRuleNodeForContent(nsIContent* aContent,
     doc->GetShellAt(0, getter_AddRefs(presShell));
     NS_ENSURE_TRUE(presShell, NS_ERROR_UNEXPECTED);
 
-    nsCOMPtr<nsIStyleContext> sContext;
-    nsresult rv = GetStyleContextForContent(aContent, presShell,
-                                            getter_AddRefs(sContext));
-    NS_ENSURE_SUCCESS(rv, rv);
-
-    return sContext->GetRuleNode(aRuleNode);
+    nsRefPtr<nsStyleContext> sContext = GetStyleContextForContent(aContent, presShell);
+    sContext->GetRuleNode(aRuleNode);
+    return NS_OK;
 }
diff --git a/mozilla/layout/style/nsInspectorCSSUtils.h b/mozilla/layout/style/nsInspectorCSSUtils.h
index eef6a8176a3..65158b2b7a3 100644
--- a/mozilla/layout/style/nsInspectorCSSUtils.h
+++ b/mozilla/layout/style/nsInspectorCSSUtils.h
@@ -41,9 +41,10 @@
 #define nsInspectorCSSUtils_h___
 
 #include "nsIInspectorCSSUtils.h"
+#include "nsStyleContext.h"
+#include "nsAutoPtr.h"
 
 class nsIPresShell;
-class nsIStyleContext;
 
 class nsInspectorCSSUtils : public nsIInspectorCSSUtils {
 
@@ -64,11 +65,10 @@ public:
                                      nsRuleNode** aRuleNode);
 
 private:
-    nsresult GetStyleContextForContent(nsIContent* aContent,
-                                       nsIPresShell* aPresShell,
-                                       nsIStyleContext** aStyleContext);
-    nsresult GetStyleContextForFrame(nsIFrame* aFrame,
-                                     nsIStyleContext** aStyleContext);
+    already_AddRefed<nsStyleContext>
+    GetStyleContextForContent(nsIContent* aContent, nsIPresShell* aPresShell);
+
+    nsStyleContext* GetStyleContextForFrame(nsIFrame* aFrame);
 };
 
 #endif /* nsInspectorCSSUtils_h___ */
diff --git a/mozilla/layout/style/nsRuleNode.cpp b/mozilla/layout/style/nsRuleNode.cpp
index 9d688900ec4..270f7bc6cef 100644
--- a/mozilla/layout/style/nsRuleNode.cpp
+++ b/mozilla/layout/style/nsRuleNode.cpp
@@ -52,6 +52,7 @@
 #include "nsThemeConstants.h"
 #include "nsITheme.h"
 #include "pldhash.h"
+#include "nsStyleContext.h"
 
 /*
  * For storage of an |nsRuleNode|'s children in a linked list.
@@ -198,7 +199,7 @@ nsString& Unquote(nsString& aString)
 
 nscoord CalcLength(const nsCSSValue& aValue,
                    const nsFont* aFont, 
-                   nsIStyleContext* aStyleContext,
+                   nsStyleContext* aStyleContext,
                    nsIPresContext* aPresContext,
                    PRBool& aInherited)
 {
@@ -269,7 +270,7 @@ nscoord CalcLength(const nsCSSValue& aValue,
 
 static PRBool SetCoord(const nsCSSValue& aValue, nsStyleCoord& aCoord, 
                        const nsStyleCoord& aParentCoord,
-                       PRInt32 aMask, nsIStyleContext* aStyleContext,
+                       PRInt32 aMask, nsStyleContext* aStyleContext,
                        nsIPresContext* aPresContext, PRBool& aInherited)
 {
   PRBool  result = PR_TRUE;
@@ -1207,7 +1208,7 @@ nsRuleNode::CheckSpecifiedProperties(const nsStyleStructID aSID,
 }
 
 const nsStyleStruct*
-nsRuleNode::GetDisplayData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetDisplayData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataDisplay displayData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Display, mPresContext, aContext);
@@ -1221,7 +1222,7 @@ nsRuleNode::GetDisplayData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetVisibilityData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetVisibilityData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataDisplay displayData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Visibility, mPresContext, aContext);
@@ -1231,7 +1232,7 @@ nsRuleNode::GetVisibilityData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetTextData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetTextData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataText textData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Text, mPresContext, aContext);
@@ -1241,7 +1242,7 @@ nsRuleNode::GetTextData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetTextResetData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetTextResetData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataText textData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_TextReset, mPresContext, aContext);
@@ -1251,7 +1252,7 @@ nsRuleNode::GetTextResetData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetUserInterfaceData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetUserInterfaceData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataUserInterface uiData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_UserInterface, mPresContext, aContext);
@@ -1263,7 +1264,7 @@ nsRuleNode::GetUserInterfaceData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetUIResetData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetUIResetData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataUserInterface uiData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_UIReset, mPresContext, aContext);
@@ -1275,7 +1276,7 @@ nsRuleNode::GetUIResetData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetFontData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetFontData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataFont fontData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Font, mPresContext, aContext);
@@ -1285,7 +1286,7 @@ nsRuleNode::GetFontData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetColorData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetColorData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataColor colorData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Color, mPresContext, aContext);
@@ -1295,7 +1296,7 @@ nsRuleNode::GetColorData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetBackgroundData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetBackgroundData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataColor colorData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Background, mPresContext, aContext);
@@ -1305,7 +1306,7 @@ nsRuleNode::GetBackgroundData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetMarginData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetMarginData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataMargin marginData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Margin, mPresContext, aContext);
@@ -1321,7 +1322,7 @@ nsRuleNode::GetMarginData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetBorderData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetBorderData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataMargin marginData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Border, mPresContext, aContext);
@@ -1351,7 +1352,7 @@ nsRuleNode::GetBorderData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetPaddingData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetPaddingData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataMargin marginData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Padding, mPresContext, aContext);
@@ -1367,7 +1368,7 @@ nsRuleNode::GetPaddingData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetOutlineData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetOutlineData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataMargin marginData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Outline, mPresContext, aContext);
@@ -1383,7 +1384,7 @@ nsRuleNode::GetOutlineData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetListData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetListData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataList listData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_List, mPresContext, aContext);
@@ -1398,7 +1399,7 @@ nsRuleNode::GetListData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetPositionData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetPositionData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataPosition posData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Position, mPresContext, aContext);
@@ -1413,7 +1414,7 @@ nsRuleNode::GetPositionData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetTableData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetTableData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataTable tableData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Table, mPresContext, aContext);
@@ -1423,7 +1424,7 @@ nsRuleNode::GetTableData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetTableBorderData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetTableBorderData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataTable tableData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_TableBorder, mPresContext, aContext);
@@ -1433,7 +1434,7 @@ nsRuleNode::GetTableBorderData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetContentData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetContentData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataContent contentData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Content, mPresContext, aContext);
@@ -1446,7 +1447,7 @@ nsRuleNode::GetContentData(nsIStyleContext* aContext, PRBool aComputeData)
 }
 
 const nsStyleStruct*
-nsRuleNode::GetQuotesData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetQuotesData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataContent contentData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_Quotes, mPresContext, aContext);
@@ -1459,7 +1460,7 @@ nsRuleNode::GetQuotesData(nsIStyleContext* aContext, PRBool aComputeData)
 
 #ifdef INCLUDE_XUL
 const nsStyleStruct*
-nsRuleNode::GetXULData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetXULData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataXUL xulData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_XUL, mPresContext, aContext);
@@ -1471,7 +1472,7 @@ nsRuleNode::GetXULData(nsIStyleContext* aContext, PRBool aComputeData)
 
 #ifdef MOZ_SVG
 const nsStyleStruct*
-nsRuleNode::GetSVGData(nsIStyleContext* aContext, PRBool aComputeData)
+nsRuleNode::GetSVGData(nsStyleContext* aContext, PRBool aComputeData)
 {
   nsRuleDataSVG svgData; // Declare a struct with null CSS values.
   nsRuleData ruleData(eStyleStruct_SVG, mPresContext, aContext);
@@ -1483,7 +1484,7 @@ nsRuleNode::GetSVGData(nsIStyleContext* aContext, PRBool aComputeData)
 
 const nsStyleStruct*
 nsRuleNode::WalkRuleTree(const nsStyleStructID aSID,
-                         nsIStyleContext* aContext, 
+                         nsStyleContext* aContext, 
                          nsRuleData* aRuleData,
                          nsRuleDataStruct* aSpecificData,
                          PRBool aComputeData)
@@ -1591,7 +1592,7 @@ nsRuleNode::WalkRuleTree(const nsStyleStructID aSID,
     // All information must necessarily be inherited from our parent style context.
     // In the absence of any computed data in the rule tree and with
     // no rules specified that didn't have values of 'inherit', we should check our parent.
-    nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+    nsStyleContext* parentContext = aContext->GetParent();
     if (parentContext) {
       // We have a parent, and so we should just inherit from the parent.
       // Set the inherit bits on our context.  These bits tell the style context that
@@ -1654,7 +1655,7 @@ IsChrome(nsIPresContext* aPresContext)
 }
 
 const nsStyleStruct*
-nsRuleNode::SetDefaultOnRoot(const nsStyleStructID aSID, nsIStyleContext* aContext)
+nsRuleNode::SetDefaultOnRoot(const nsStyleStructID aSID, nsStyleContext* aContext)
 {
   switch (aSID) {
     case eStyleStruct_Font: 
@@ -1817,7 +1818,7 @@ nsRuleNode::gComputeStyleDataFn[] = {
 };
 
 static void
-SetFont(nsIPresContext* aPresContext, nsIStyleContext* aContext,
+SetFont(nsIPresContext* aPresContext, nsStyleContext* aContext,
         nscoord aMinFontSize, PRBool aUseDocumentFonts, PRBool aChromeOverride,
         PRBool aIsGeneric, const nsRuleDataFont& aFontData,
         const nsFont& aDefaultFont, const nsStyleFont* aParentFont,
@@ -2106,14 +2107,14 @@ SetFont(nsIPresContext* aPresContext, nsIStyleContext* aContext,
 //    up to the root where default values come from the presentation context)
 //  - re-apply cascading rules from there without caching intermediate values
 static void
-SetGenericFont(nsIPresContext* aPresContext, nsIStyleContext* aContext,
+SetGenericFont(nsIPresContext* aPresContext, nsStyleContext* aContext,
                const nsRuleDataFont& aFontData, PRUint8 aGenericFontID,
                nscoord aMinFontSize, PRBool aUseDocumentFonts,
                PRBool aChromeOverride, nsStyleFont* aFont)
 {
   // walk up the contexts until a context with the desired generic font
   nsAutoVoidArray contextPath;
-  nsCOMPtr<nsIStyleContext> higherContext = aContext->GetParent();
+  nsStyleContext* higherContext = aContext->GetParent();
   while (higherContext) {
     contextPath.AppendElement(higherContext);
     const nsStyleFont* higherFont = (const nsStyleFont*)higherContext->GetStyleData(eStyleStruct_Font);
@@ -2135,7 +2136,7 @@ SetGenericFont(nsIPresContext* aPresContext, nsIStyleContext* aContext,
   PRInt32 i = contextPath.Count() - 1;
   PRBool zoom = PR_TRUE;
   if (higherContext) {
-    nsIStyleContext* context = (nsIStyleContext*)contextPath[i];
+    nsStyleContext* context = (nsStyleContext*)contextPath[i];
     nsStyleFont* tmpFont = (nsStyleFont*)context->GetStyleData(eStyleStruct_Font);
     parentFont.mFlags = tmpFont->mFlags;
     parentFont.mFont = tmpFont->mFont;
@@ -2155,7 +2156,7 @@ SetGenericFont(nsIPresContext* aPresContext, nsIStyleContext* aContext,
   nsCOMPtr<nsIStyleRule> rule;
 
   for (; i >= 0; --i) {
-    nsIStyleContext* context = (nsIStyleContext*)contextPath[i];
+    nsStyleContext* context = (nsStyleContext*)contextPath[i];
     nsRuleDataFont fontData; // Declare a struct with null CSS values.
     nsRuleData ruleData(eStyleStruct_Font, aPresContext, context);
     ruleData.mFontData = &fontData;
@@ -2203,11 +2204,11 @@ SetGenericFont(nsIPresContext* aPresContext, nsIStyleContext* aContext,
 const nsStyleStruct* 
 nsRuleNode::ComputeFontData(nsStyleStruct* aStartStruct,
                             const nsRuleDataStruct& aData, 
-                            nsIStyleContext* aContext, 
+                            nsStyleContext* aContext, 
                             nsRuleNode* aHighestNode,
                             const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
 
   const nsRuleDataFont& fontData = NS_STATIC_CAST(const nsRuleDataFont&, aData);
   nsStyleFont* font = nsnull;
@@ -2333,11 +2334,11 @@ nsRuleNode::ComputeFontData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputeTextData(nsStyleStruct* aStartStruct,
                             const nsRuleDataStruct& aData, 
-                            nsIStyleContext* aContext, 
+                            nsStyleContext* aContext, 
                             nsRuleNode* aHighestNode,
                             const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
 
   const nsRuleDataText& textData = NS_STATIC_CAST(const nsRuleDataText&, aData);
   nsStyleText* text = nsnull;
@@ -2454,11 +2455,11 @@ nsRuleNode::ComputeTextData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputeTextResetData(nsStyleStruct* aStartData,
                                  const nsRuleDataStruct& aData, 
-                                 nsIStyleContext* aContext, 
+                                 nsStyleContext* aContext, 
                                  nsRuleNode* aHighestNode,
                                  const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
 
   const nsRuleDataText& textData = NS_STATIC_CAST(const nsRuleDataText&, aData);
   nsStyleTextReset* text;
@@ -2537,12 +2538,12 @@ nsRuleNode::ComputeTextResetData(nsStyleStruct* aStartData,
 const nsStyleStruct*
 nsRuleNode::ComputeUserInterfaceData(nsStyleStruct* aStartData,
                                      const nsRuleDataStruct& aData, 
-                                     nsIStyleContext* aContext, 
+                                     nsStyleContext* aContext, 
                                      nsRuleNode* aHighestNode,
                                      const RuleDetail& aRuleDetail,
                                      PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataUserInterface& uiData = NS_STATIC_CAST(const nsRuleDataUserInterface&, aData);
   nsStyleUserInterface* ui = nsnull;
@@ -2649,11 +2650,11 @@ nsRuleNode::ComputeUserInterfaceData(nsStyleStruct* aStartData,
 const nsStyleStruct*
 nsRuleNode::ComputeUIResetData(nsStyleStruct* aStartData,
                                const nsRuleDataStruct& aData, 
-                               nsIStyleContext* aContext, 
+                               nsStyleContext* aContext, 
                                nsRuleNode* aHighestNode,
                                const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataUserInterface& uiData = NS_STATIC_CAST(const nsRuleDataUserInterface&, aData);
   nsStyleUIReset* ui;
@@ -2739,11 +2740,11 @@ nsRuleNode::ComputeUIResetData(nsStyleStruct* aStartData,
 const nsStyleStruct*
 nsRuleNode::ComputeDisplayData(nsStyleStruct* aStartStruct,
                                const nsRuleDataStruct& aData, 
-                               nsIStyleContext* aContext, 
+                               nsStyleContext* aContext, 
                                nsRuleNode* aHighestNode,
                                const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataDisplay& displayData = NS_STATIC_CAST(const nsRuleDataDisplay&, aData);
   nsStyleDisplay* display;
@@ -2755,8 +2756,7 @@ nsRuleNode::ComputeDisplayData(nsStyleStruct* aStartStruct,
     display = new (mPresContext) nsStyleDisplay();
   const nsStyleDisplay* parentDisplay = display;
 
-  nsCOMPtr<nsIAtom> pseudoTag;
-  aContext->GetPseudoType(*getter_AddRefs(pseudoTag));
+  nsCOMPtr<nsIAtom> pseudoTag = aContext->GetPseudoType();
   PRBool generatedContent = (pseudoTag == nsCSSPseudoElements::before || 
                              pseudoTag == nsCSSPseudoElements::after);
 
@@ -2998,11 +2998,11 @@ nsRuleNode::ComputeDisplayData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputeVisibilityData(nsStyleStruct* aStartStruct,
                                   const nsRuleDataStruct& aData, 
-                                  nsIStyleContext* aContext, 
+                                  nsStyleContext* aContext, 
                                   nsRuleNode* aHighestNode,
                                   const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataDisplay& displayData = NS_STATIC_CAST(const nsRuleDataDisplay&, aData);
   nsStyleVisibility* visibility = nsnull;
@@ -3107,11 +3107,11 @@ nsRuleNode::ComputeVisibilityData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputeColorData(nsStyleStruct* aStartStruct,
                              const nsRuleDataStruct& aData, 
-                             nsIStyleContext* aContext, 
+                             nsStyleContext* aContext, 
                              nsRuleNode* aHighestNode,
                              const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataColor& colorData = NS_STATIC_CAST(const nsRuleDataColor&, aData);
   nsStyleColor* color = nsnull;
@@ -3164,11 +3164,11 @@ nsRuleNode::ComputeColorData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputeBackgroundData(nsStyleStruct* aStartStruct,
                                   const nsRuleDataStruct& aData, 
-                                  nsIStyleContext* aContext, 
+                                  nsStyleContext* aContext, 
                                   nsRuleNode* aHighestNode,
                                   const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataColor& colorData = NS_STATIC_CAST(const nsRuleDataColor&, aData);
   nsStyleBackground* bg;
@@ -3354,11 +3354,11 @@ static const CSSRectSide gCSSSides[] = {
 const nsStyleStruct*
 nsRuleNode::ComputeMarginData(nsStyleStruct* aStartStruct,
                               const nsRuleDataStruct& aData, 
-                              nsIStyleContext* aContext, 
+                              nsStyleContext* aContext, 
                               nsRuleNode* aHighestNode,
                               const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataMargin& marginData = NS_STATIC_CAST(const nsRuleDataMargin&, aData);
   nsStyleMargin* margin;
@@ -3411,11 +3411,11 @@ nsRuleNode::ComputeMarginData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeBorderData(nsStyleStruct* aStartStruct,
                               const nsRuleDataStruct& aData, 
-                              nsIStyleContext* aContext, 
+                              nsStyleContext* aContext, 
                               nsRuleNode* aHighestNode,
                               const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataMargin& marginData = NS_STATIC_CAST(const nsRuleDataMargin&, aData);
   nsStyleBorder* border;
@@ -3517,7 +3517,7 @@ nsRuleNode::ComputeBorderData(nsStyleStruct* aStartStruct,
           // computed (unlike for the element where this will be used, for
           // which the color could be specified on a more specific rule).
           const nsStyleColor *parentColor;
-          ::GetStyleData(parentContext.get(), &parentColor);
+          ::GetStyleData(parentContext, &parentColor);
           border->SetBorderColor(side, parentColor->mColor);
         } else
           border->SetBorderColor(side, borderColor);
@@ -3579,11 +3579,11 @@ nsRuleNode::ComputeBorderData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputePaddingData(nsStyleStruct* aStartStruct,
                                const nsRuleDataStruct& aData, 
-                               nsIStyleContext* aContext, 
+                               nsStyleContext* aContext, 
                                nsRuleNode* aHighestNode,
                                const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataMargin& marginData = NS_STATIC_CAST(const nsRuleDataMargin&, aData);
   nsStylePadding* padding;
@@ -3636,11 +3636,11 @@ nsRuleNode::ComputePaddingData(nsStyleStruct* aStartStruct,
 const nsStyleStruct*
 nsRuleNode::ComputeOutlineData(nsStyleStruct* aStartStruct,
                                const nsRuleDataStruct& aData, 
-                               nsIStyleContext* aContext, 
+                               nsStyleContext* aContext, 
                                nsRuleNode* aHighestNode,
                                const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataMargin& marginData = NS_STATIC_CAST(const nsRuleDataMargin&, aData);
   nsStyleOutline* outline;
@@ -3709,11 +3709,11 @@ nsRuleNode::ComputeOutlineData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeListData(nsStyleStruct* aStartStruct,
                             const nsRuleDataStruct& aData, 
-                            nsIStyleContext* aContext, 
+                            nsStyleContext* aContext, 
                             nsRuleNode* aHighestNode,
                             const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataList& listData = NS_STATIC_CAST(const nsRuleDataList&, aData);
   nsStyleList* list = nsnull;
@@ -3826,11 +3826,11 @@ nsRuleNode::ComputeListData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputePositionData(nsStyleStruct* aStartStruct,
                                 const nsRuleDataStruct& aData, 
-                                nsIStyleContext* aContext, 
+                                nsStyleContext* aContext, 
                                 nsRuleNode* aHighestNode,
                                 const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataPosition& posData = NS_STATIC_CAST(const nsRuleDataPosition&, aData);
   nsStylePosition* pos;
@@ -3935,11 +3935,11 @@ nsRuleNode::ComputePositionData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeTableData(nsStyleStruct* aStartStruct,
                              const nsRuleDataStruct& aData, 
-                             nsIStyleContext* aContext, 
+                             nsStyleContext* aContext, 
                              nsRuleNode* aHighestNode,
                              const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataTable& tableData = NS_STATIC_CAST(const nsRuleDataTable&, aData);
   nsStyleTable* table;
@@ -4006,11 +4006,11 @@ nsRuleNode::ComputeTableData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeTableBorderData(nsStyleStruct* aStartStruct,
                                    const nsRuleDataStruct& aData, 
-                                   nsIStyleContext* aContext, 
+                                   nsStyleContext* aContext, 
                                    nsRuleNode* aHighestNode,
                                    const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataTable& tableData = NS_STATIC_CAST(const nsRuleDataTable&, aData);
   nsStyleTableBorder* table = nsnull;
@@ -4105,11 +4105,11 @@ nsRuleNode::ComputeTableBorderData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeContentData(nsStyleStruct* aStartStruct,
                                const nsRuleDataStruct& aData, 
-                               nsIStyleContext* aContext, 
+                               nsStyleContext* aContext, 
                                nsRuleNode* aHighestNode,
                                const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataContent& contentData = NS_STATIC_CAST(const nsRuleDataContent&, aData);
   nsStyleContent* content;
@@ -4301,11 +4301,11 @@ nsRuleNode::ComputeContentData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeQuotesData(nsStyleStruct* aStartStruct,
                               const nsRuleDataStruct& aData, 
-                              nsIStyleContext* aContext, 
+                              nsStyleContext* aContext, 
                               nsRuleNode* aHighestNode,
                               const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataContent& contentData = NS_STATIC_CAST(const nsRuleDataContent&, aData);
   nsStyleQuotes* quotes = nsnull;
@@ -4395,11 +4395,11 @@ nsRuleNode::ComputeQuotesData(nsStyleStruct* aStartStruct,
 const nsStyleStruct* 
 nsRuleNode::ComputeXULData(nsStyleStruct* aStartStruct,
                            const nsRuleDataStruct& aData, 
-                           nsIStyleContext* aContext, 
+                           nsStyleContext* aContext, 
                            nsRuleNode* aHighestNode,
                            const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
   
   const nsRuleDataXUL& xulData = NS_STATIC_CAST(const nsRuleDataXUL&, aData);
   nsStyleXUL* xul = nsnull;
@@ -4517,7 +4517,7 @@ SetSVGOpacity(const nsCSSValue& aValue, float parentOpacity, float& opacity, PRB
 
 static void
 SetSVGLength(const nsCSSValue& aValue, float parentLength, float& length,
-             nsIStyleContext* aContext, nsIPresContext* aPresContext, PRBool& aInherited)
+             nsStyleContext* aContext, nsIPresContext* aPresContext, PRBool& aInherited)
 {
   nsStyleCoord coord;
   PRBool dummy;
@@ -4545,11 +4545,11 @@ SetSVGLength(const nsCSSValue& aValue, float parentLength, float& length,
 const nsStyleStruct* 
 nsRuleNode::ComputeSVGData(nsStyleStruct* aStartStruct,
                            const nsRuleDataStruct& aData, 
-                           nsIStyleContext* aContext, 
+                           nsStyleContext* aContext, 
                            nsRuleNode* aHighestNode,
                            const RuleDetail& aRuleDetail, PRBool aInherited)
 {
-  nsCOMPtr<nsIStyleContext> parentContext = aContext->GetParent();
+  nsStyleContext* parentContext = aContext->GetParent();
 
   nsStyleSVG* svg = nsnull;
   nsStyleSVG* parentSVG = svg;
@@ -4692,7 +4692,7 @@ nsRuleNode::gGetStyleDataFn[] = {
 
 const nsStyleStruct* 
 nsRuleNode::GetStyleData(nsStyleStructID aSID, 
-                         nsIStyleContext* aContext,
+                         nsStyleContext* aContext,
                          PRBool aComputeData)
 {
   const nsStyleStruct* cachedData = mStyleData.GetStyleData(aSID);
diff --git a/mozilla/layout/style/nsRuleNode.h b/mozilla/layout/style/nsRuleNode.h
index 746e6dd01df..fe978d1ab8c 100644
--- a/mozilla/layout/style/nsRuleNode.h
+++ b/mozilla/layout/style/nsRuleNode.h
@@ -42,13 +42,13 @@
 
 #include "nsCOMPtr.h"
 #include "nsIStyleRule.h"
-#include "nsIFrame.h"
 #include "nsFixedSizeAllocator.h"
 #include "nsIPresContext.h"
 #include "nsCSSDeclaration.h"
 #include "nsILanguageAtomService.h"
+#include "nsStyleStruct.h"
 
-class nsIStyleContext;
+class nsStyleContext;
 struct nsRuleList;
 struct PLDHashTable;
 
@@ -245,7 +245,7 @@ struct nsRuleData
   nsStyleStructID mSID;
   PRPackedBool mCanStoreInRuleTree;
   nsIPresContext* mPresContext;
-  nsIStyleContext* mStyleContext;
+  nsStyleContext* mStyleContext;
   nsPostResolveFunc mPostResolveCallback;
   nsRuleDataFont* mFontData; // Should always be stack-allocated! We don't own these structures!
   nsRuleDataDisplay* mDisplayData;
@@ -266,7 +266,7 @@ struct nsRuleData
   nsRuleDataSVG* mSVGData;
 #endif
 
-  nsRuleData(const nsStyleStructID& aSID, nsIPresContext* aContext, nsIStyleContext* aStyleContext) 
+  nsRuleData(const nsStyleStructID& aSID, nsIPresContext* aContext, nsStyleContext* aStyleContext) 
     :mSID(aSID), mPresContext(aContext), mStyleContext(aStyleContext), mPostResolveCallback(nsnull),
      mFontData(nsnull), mDisplayData(nsnull), mMarginData(nsnull), mListData(nsnull), 
      mPositionData(nsnull), mTableData(nsnull), mColorData(nsnull), mContentData(nsnull), mTextData(nsnull),
@@ -409,89 +409,89 @@ protected:
   void PropagateDependentBit(PRUint32 aBit, nsRuleNode* aHighestNode);
   void PropagateNoneBit(PRUint32 aBit, nsRuleNode* aHighestNode);
   
-  const nsStyleStruct* SetDefaultOnRoot(const nsStyleStructID aSID, nsIStyleContext* aContext);
+  const nsStyleStruct* SetDefaultOnRoot(const nsStyleStructID aSID, nsStyleContext* aContext);
 
-  const nsStyleStruct* WalkRuleTree(const nsStyleStructID aSID, nsIStyleContext* aContext, 
+  const nsStyleStruct* WalkRuleTree(const nsStyleStructID aSID, nsStyleContext* aContext, 
                                     nsRuleData* aRuleData,
                                     nsRuleDataStruct* aSpecificData,
                                     PRBool aComputeData);
 
   const nsStyleStruct* ComputeDisplayData(nsStyleStruct* aStartDisplay, const nsRuleDataStruct& aDisplayData, 
-                                          nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                          nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                           const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeVisibilityData(nsStyleStruct* aStartVisibility, const nsRuleDataStruct& aDisplayData, 
-                                             nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                             nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                              const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeFontData(nsStyleStruct* aStartFont, const nsRuleDataStruct& aFontData, 
-                                       nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                       nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                        const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeColorData(nsStyleStruct* aStartColor, const nsRuleDataStruct& aColorData, 
-                                        nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                        nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                         const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeBackgroundData(nsStyleStruct* aStartBackground, const nsRuleDataStruct& aColorData, 
-                                             nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                             nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                              const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeMarginData(nsStyleStruct* aStartMargin, const nsRuleDataStruct& aMarginData, 
-                                         nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                         nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                          const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeBorderData(nsStyleStruct* aStartBorder, const nsRuleDataStruct& aMarginData, 
-                                         nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                         nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                          const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputePaddingData(nsStyleStruct* aStartPadding, const nsRuleDataStruct& aMarginData, 
-                                          nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                          nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                           const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeOutlineData(nsStyleStruct* aStartOutline, const nsRuleDataStruct& aMarginData, 
-                                          nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                          nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                           const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeListData(nsStyleStruct* aStartList, const nsRuleDataStruct& aListData, 
-                                       nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                       nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                        const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputePositionData(nsStyleStruct* aStartPosition, const nsRuleDataStruct& aPositionData, 
-                                           nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                           nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                            const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeTableData(nsStyleStruct* aStartTable, const nsRuleDataStruct& aTableData, 
-                                        nsIStyleContext* aContext, nsRuleNode* aHighestNode,
+                                        nsStyleContext* aContext, nsRuleNode* aHighestNode,
                                         const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeTableBorderData(nsStyleStruct* aStartTable, const nsRuleDataStruct& aTableData, 
-                                              nsIStyleContext* aContext,  
+                                              nsStyleContext* aContext,  
                                               nsRuleNode* aHighestNode,
                                               const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeContentData(nsStyleStruct* aStartContent, const nsRuleDataStruct& aData, 
-                                          nsIStyleContext* aContext,  
+                                          nsStyleContext* aContext,  
                                           nsRuleNode* aHighestNode,
                                           const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeQuotesData(nsStyleStruct* aStartQuotes, const nsRuleDataStruct& aData, 
-                                         nsIStyleContext* aContext,  
+                                         nsStyleContext* aContext,  
                                          nsRuleNode* aHighestNode,
                                          const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeTextData(nsStyleStruct* aStartData, const nsRuleDataStruct& aData, 
-                                       nsIStyleContext* aContext,  
+                                       nsStyleContext* aContext,  
                                        nsRuleNode* aHighestNode,
                                        const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeTextResetData(nsStyleStruct* aStartData, const nsRuleDataStruct& aData, 
-                                            nsIStyleContext* aContext,  
+                                            nsStyleContext* aContext,  
                                             nsRuleNode* aHighestNode,
                                             const RuleDetail& aRuleDetail, PRBool aInherited);
   const nsStyleStruct* ComputeUserInterfaceData(nsStyleStruct* aStartData,
                                                 const nsRuleDataStruct& aData, 
-                                                nsIStyleContext* aContext,  
+                                                nsStyleContext* aContext,  
                                                 nsRuleNode* aHighestNode,
                                                 const RuleDetail& aRuleDetail,
                                                 PRBool aInherited);
   const nsStyleStruct* ComputeUIResetData(nsStyleStruct* aStartData, const nsRuleDataStruct& aData, 
-                                          nsIStyleContext* aContext,  
+                                          nsStyleContext* aContext,  
                                           nsRuleNode* aHighestNode,
                                           const RuleDetail& aRuleDetail, PRBool aInherited);
 #ifdef INCLUDE_XUL
   const nsStyleStruct* ComputeXULData(nsStyleStruct* aStartXUL, const nsRuleDataStruct& aXULData, 
-                                      nsIStyleContext* aContext,  
+                                      nsStyleContext* aContext,  
                                       nsRuleNode* aHighestNode,
                                       const RuleDetail& aRuleDetail, PRBool aInherited);
 #endif
 
 #ifdef MOZ_SVG
   const nsStyleStruct* ComputeSVGData(nsStyleStruct* aStartSVG, const nsRuleDataStruct& aSVGData, 
-                                      nsIStyleContext* aContext,  
+                                      nsStyleContext* aContext,  
                                       nsRuleNode* aHighestNode,
                                       const RuleDetail& aRuleDetail, PRBool aInherited);
 #endif
@@ -499,7 +499,7 @@ protected:
   typedef const nsStyleStruct*
   (nsRuleNode::*ComputeStyleDataFn)(nsStyleStruct* aStartStruct,
                                     const nsRuleDataStruct& aStartData,
-                                    nsIStyleContext* aContext,
+                                    nsStyleContext* aContext,
                                     nsRuleNode* aHighestNode,
                                     const RuleDetail& aRuleDetail,
                                     PRBool aInherited);
@@ -509,33 +509,33 @@ protected:
   inline RuleDetail CheckSpecifiedProperties(const nsStyleStructID aSID, const nsRuleDataStruct& aRuleDataStruct);
 
   const nsStyleStruct* GetParentData(const nsStyleStructID aSID);
-  const nsStyleStruct* GetDisplayData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetVisibilityData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetFontData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetColorData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetBackgroundData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetMarginData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetBorderData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetPaddingData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetOutlineData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetListData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetPositionData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetTableData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetTableBorderData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetContentData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetQuotesData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetTextData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetTextResetData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetUserInterfaceData(nsIStyleContext* aContext, PRBool aComputeData);
-  const nsStyleStruct* GetUIResetData(nsIStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetDisplayData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetVisibilityData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetFontData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetColorData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetBackgroundData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetMarginData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetBorderData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetPaddingData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetOutlineData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetListData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetPositionData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetTableData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetTableBorderData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetContentData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetQuotesData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetTextData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetTextResetData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetUserInterfaceData(nsStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetUIResetData(nsStyleContext* aContext, PRBool aComputeData);
 #ifdef INCLUDE_XUL
-  const nsStyleStruct* GetXULData(nsIStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetXULData(nsStyleContext* aContext, PRBool aComputeData);
 #endif
 #ifdef MOZ_SVG
-  const nsStyleStruct* GetSVGData(nsIStyleContext* aContext, PRBool aComputeData);
+  const nsStyleStruct* GetSVGData(nsStyleContext* aContext, PRBool aComputeData);
 #endif
 
-  typedef const nsStyleStruct* (nsRuleNode::*GetStyleDataFn)(nsIStyleContext*, PRBool);
+  typedef const nsStyleStruct* (nsRuleNode::*GetStyleDataFn)(nsStyleContext*, PRBool);
   static GetStyleDataFn gGetStyleDataFn[];
 
 public:
@@ -568,7 +568,7 @@ public:
   nsresult GetPresContext(nsIPresContext** aResult);
   nsresult PathContainsRule(nsIStyleRule* aRule, PRBool* aMatched);
   const nsStyleStruct* GetStyleData(nsStyleStructID aSID, 
-                                    nsIStyleContext* aContext,
+                                    nsStyleContext* aContext,
                                     PRBool aComputeData);
 };
 
diff --git a/mozilla/layout/style/nsStyleContext.cpp b/mozilla/layout/style/nsStyleContext.cpp
index 13428a4cd56..ed785cfac24 100644
--- a/mozilla/layout/style/nsStyleContext.cpp
+++ b/mozilla/layout/style/nsStyleContext.cpp
@@ -54,6 +54,7 @@
 
 #include "nsRuleNode.h"
 #include "nsUnitConversion.h"
+#include "nsStyleContext.h"
 
 #ifdef DEBUG
 // #define NOISY_DEBUG
@@ -61,87 +62,8 @@
 
 //----------------------------------------------------------------------
 
-class nsStyleContext : public nsIStyleContext 
-{
-public:
-  nsStyleContext(nsIStyleContext* aParent, nsIAtom* aPseudoTag, 
-                 nsRuleNode* aRuleNode, nsIPresContext* aPresContext);
-  virtual ~nsStyleContext();
 
-  void* operator new(size_t sz, nsIPresContext* aPresContext) CPP_THROW_NEW;
-  void Destroy();
-
-  NS_DECL_ISUPPORTS
-
-  virtual already_AddRefed<nsIStyleContext> GetParent(void) const;
-  NS_IMETHOD GetFirstChild(nsIStyleContext** aContext);
-
-  NS_IMETHOD GetPseudoType(nsIAtom*& aPseudoTag) const;
-
-  NS_IMETHOD FindChildWithRules(const nsIAtom* aPseudoTag, nsRuleNode* aRules,
-                                nsIStyleContext*& aResult);
-
-  virtual PRBool    Equals(const nsIStyleContext* aOther) const;
-  virtual PRBool    HasTextDecorations() { return mBits & NS_STYLE_HAS_TEXT_DECORATIONS; };
-
-  NS_IMETHOD GetBorderPaddingFor(nsStyleBorderPadding& aBorderPadding);
-
-  NS_IMETHOD GetStyle(nsStyleStructID aSID, const nsStyleStruct** aStruct);
-  NS_IMETHOD SetStyle(nsStyleStructID aSID, nsStyleStruct* aStruct);
-
-  NS_IMETHOD GetRuleNode(nsRuleNode** aResult) { *aResult = mRuleNode; return NS_OK; };
-  NS_IMETHOD AddStyleBit(const PRUint32& aBit) { mBits |= aBit; return NS_OK; };
-  NS_IMETHOD GetStyleBits(PRUint32* aBits) { *aBits = mBits; return NS_OK; };
-
-  virtual const nsStyleStruct* GetStyleData(nsStyleStructID aSID);
-  const nsStyleStruct* PeekStyleData(nsStyleStructID aSID);
-
-  virtual nsStyleStruct* GetUniqueStyleData(nsIPresContext* aPresContext, const nsStyleStructID& aSID);
-
-  virtual nsresult ClearCachedDataForRule(nsIStyleRule* aRule);
-
-  virtual nsresult ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule);
-
-  NS_IMETHOD  CalcStyleDifference(nsIStyleContext* aOther, nsChangeHint& aHint);
-
-#ifdef DEBUG
-  virtual void DumpRegressionData(nsIPresContext* aPresContext, FILE* out, PRInt32 aIndent);
-
-  virtual void List(FILE* out, PRInt32 aIndent);
-
-  virtual void SizeOf(nsISizeOfHandler *aSizeOfHandler, PRUint32 &aSize);
-#endif
-
-protected:
-  void AppendChild(nsStyleContext* aChild);
-  void RemoveChild(nsStyleContext* aChild);
-
-  void ApplyStyleFixups(nsIPresContext* aPresContext);
-
-  nsStyleContext* mParent;
-  nsStyleContext* mChild;
-  nsStyleContext* mEmptyChild;
-  nsStyleContext* mPrevSibling;
-  nsStyleContext* mNextSibling;
-
-  // If this style context is for a pseudo-element, the pseudo-element
-  // atom.  Otherwise, null.
-  nsCOMPtr<nsIAtom> mPseudoTag;
-
-  nsRuleNode*             mRuleNode;
-
-  // |mCachedStyleData| points to both structs that are owned by this
-  // style context and structs that are owned by one of this style
-  // context's ancestors (which are indirectly owned since this style
-  // context owns a reference to its parent).  If the bit in |mBits| is
-  // set for a struct, that means that the pointer for that struct is
-  // owned by an ancestor rather than by this style context.
-  nsCachedStyleData       mCachedStyleData; // Our cached style data.
-  PRUint32                mBits; // Which structs are inherited from the
-                                 // parent context.
-};
-
-nsStyleContext::nsStyleContext(nsIStyleContext* aParent,
+nsStyleContext::nsStyleContext(nsStyleContext* aParent,
                                nsIAtom* aPseudoTag,
                                nsRuleNode* aRuleNode,
                                nsIPresContext* aPresContext)
@@ -150,13 +72,13 @@ nsStyleContext::nsStyleContext(nsIStyleContext* aParent,
     mEmptyChild(nsnull),
     mPseudoTag(aPseudoTag),
     mRuleNode(aRuleNode),
-    mBits(0)
+    mBits(0),
+    mRefCnt(0)
 {
-  
   mNextSibling = this;
   mPrevSibling = this;
   if (mParent) {
-    NS_ADDREF(mParent);
+    mParent->AddRef();
     mParent->AppendChild(this);
   }
 
@@ -173,7 +95,7 @@ nsStyleContext::~nsStyleContext()
 
   if (mParent) {
     mParent->RemoveChild(this);
-    NS_RELEASE(mParent);
+    mParent->Release();
   }
 
   // Free up our data structs.
@@ -184,24 +106,6 @@ nsStyleContext::~nsStyleContext()
   }
 }
 
-NS_IMPL_ADDREF(nsStyleContext)
-NS_IMPL_RELEASE_WITH_DESTROY(nsStyleContext, Destroy())
-NS_IMPL_QUERY_INTERFACE1(nsStyleContext, nsIStyleContext)
-
-already_AddRefed<nsIStyleContext> nsStyleContext::GetParent(void) const
-{
-  NS_IF_ADDREF(mParent);
-  return mParent;
-}
-
-NS_IMETHODIMP
-nsStyleContext::GetFirstChild(nsIStyleContext** aContext)
-{
-  *aContext = mChild;
-  NS_IF_ADDREF(*aContext);
-  return NS_OK;
-}
-
 void nsStyleContext::AppendChild(nsStyleContext* aChild)
 {
   if (aChild->mRuleNode->IsRoot()) {
@@ -263,23 +167,22 @@ void nsStyleContext::RemoveChild(nsStyleContext* aChild)
   aChild->mPrevSibling = aChild;
 }
 
-NS_IMETHODIMP
-nsStyleContext::GetPseudoType(nsIAtom*& aPseudoTag) const
+already_AddRefed<nsIAtom>
+nsStyleContext::GetPseudoType() const
 {
-  aPseudoTag = mPseudoTag;
-  NS_IF_ADDREF(aPseudoTag);
-  return NS_OK;
+  nsIAtom* pseudoTag = mPseudoTag;
+  NS_IF_ADDREF(pseudoTag);
+  return pseudoTag;
 }
 
-NS_IMETHODIMP
+already_AddRefed<nsStyleContext>
 nsStyleContext::FindChildWithRules(const nsIAtom* aPseudoTag, 
-                                     nsRuleNode* aRuleNode,
-                                     nsIStyleContext*& aResult)
+                                   nsRuleNode* aRuleNode)
 {
   PRUint32 threshold = 10; // The # of siblings we're willing to examine
                            // before just giving this whole thing up.
 
-  aResult = nsnull;
+  nsStyleContext* aResult = nsnull;
 
   if ((nsnull != mChild) || (nsnull != mEmptyChild)) {
     nsStyleContext* child;
@@ -313,12 +216,15 @@ nsStyleContext::FindChildWithRules(const nsIAtom* aPseudoTag,
       } while (child != mChild);
     }
   }
-  NS_IF_ADDREF(aResult);
-  return NS_OK;
+
+  if (aResult)
+    aResult->AddRef();
+
+  return aResult;
 }
 
 
-PRBool nsStyleContext::Equals(const nsIStyleContext* aOther) const
+PRBool nsStyleContext::Equals(const nsStyleContext* aOther) const
 {
   PRBool  result = PR_TRUE;
   const nsStyleContext* other = (nsStyleContext*)aOther;
@@ -358,7 +264,7 @@ inline const nsStyleStruct* nsStyleContext::PeekStyleData(nsStyleStructID aSID)
   return mRuleNode->GetStyleData(aSID, this, PR_FALSE); // Our rule node will take care of it for us.
 }
 
-NS_IMETHODIMP
+void
 nsStyleContext::GetBorderPaddingFor(nsStyleBorderPadding& aBorderPadding)
 {
   nsMargin border, padding;
@@ -370,8 +276,6 @@ nsStyleContext::GetBorderPaddingFor(nsStyleBorderPadding& aBorderPadding)
       aBorderPadding.SetBorderPadding(border);
     }
   }
-
-  return NS_OK;
 }
 
 // This is an evil evil function, since it forces you to alloc your own separate copy of
@@ -421,14 +325,7 @@ nsStyleContext::GetUniqueStyleData(nsIPresContext* aPresContext, const nsStyleSt
   return result;
 }
 
-NS_IMETHODIMP
-nsStyleContext::GetStyle(nsStyleStructID aSID, const nsStyleStruct** aStruct)
-{
-  *aStruct = GetStyleData(aSID);
-  return NS_OK;
-}
-
-NS_IMETHODIMP
+void
 nsStyleContext::SetStyle(nsStyleStructID aSID, nsStyleStruct* aStruct)
 {
   // This method should only be called from nsRuleNode!  It is not a public
@@ -461,8 +358,6 @@ nsStyleContext::SetStyle(nsStyleStructID aSID, nsStyleStruct* aStruct)
   }
   char* dataSlot = resetOrInherit + info.mInheritResetOffset;
   *NS_REINTERPRET_CAST(nsStyleStruct**, dataSlot) = aStruct;
-
-  return NS_OK;
 }
 
 void
@@ -497,7 +392,7 @@ nsStyleContext::ApplyStyleFixups(nsIPresContext* aPresContext)
   }
 }
 
-nsresult
+void
 nsStyleContext::ClearCachedDataForRule(nsIStyleRule* aInlineStyleRule)
 {
   mRuleNode->ClearCachedData(aInlineStyleRule); // XXXdwh.  If we're willing to *really* special case
@@ -505,10 +400,9 @@ nsStyleContext::ClearCachedDataForRule(nsIStyleRule* aInlineStyleRule)
                                            // that actually changed.  For example, if someone changes
                                            // style.left, we really only need to blow away cached
                                            // data in the position struct.
-  return NS_OK;
 }
 
-nsresult
+void
 nsStyleContext::ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule)
 {
   PRBool matched = PR_TRUE;
@@ -541,13 +435,12 @@ nsStyleContext::ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule
       child = child->mNextSibling;
     } while (mEmptyChild != child);
   }
-
-  return NS_OK;
 }
 
-NS_IMETHODIMP
-nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, nsChangeHint& aHint)
+nsChangeHint
+nsStyleContext::CalcStyleDifference(nsStyleContext* aOther)
 {
+  nsChangeHint hint = NS_STYLE_HINT_NONE;
   if (aOther) {
     // If our rule nodes are the same, then we are looking at the same style
     // data.  We know this because CalcStyleDifference is always called on two
@@ -557,72 +450,70 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, nsChangeHint& aHint
     nsRuleNode* ruleNode;
     aOther->GetRuleNode(&ruleNode);
     if (ruleNode == mRuleNode)
-      return NS_OK;
+      return hint;
 
     nsChangeHint maxHint = NS_STYLE_HINT_FRAMECHANGE;
     
     // We begin by examining those style structs that are capable of causing the maximal
     // difference, a FRAMECHANGE.
     // FRAMECHANGE Structs: Display, XUL, Content, UserInterface, Visibility, Quotes
-    if (!NS_IsHintSubset(maxHint, aHint)) {
-      const nsStyleDisplay* display = (const nsStyleDisplay*)PeekStyleData(eStyleStruct_Display);
-      if (display) {
-        const nsStyleDisplay* otherDisplay = (const nsStyleDisplay*)aOther->GetStyleData(eStyleStruct_Display);
-        if (display != otherDisplay) {
-          NS_UpdateHint(aHint, display->CalcDifference(*otherDisplay));
-        }
+    const nsStyleDisplay* display = (const nsStyleDisplay*)PeekStyleData(eStyleStruct_Display);
+    if (display) {
+      const nsStyleDisplay* otherDisplay = (const nsStyleDisplay*)aOther->GetStyleData(eStyleStruct_Display);
+      if (display != otherDisplay) {
+        NS_UpdateHint(hint, display->CalcDifference(*otherDisplay));
       }
     }
 
 #ifdef INCLUDE_XUL
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleXUL* xul = (const nsStyleXUL*)PeekStyleData(eStyleStruct_XUL);
       if (xul) {
         const nsStyleXUL* otherXUL = (const nsStyleXUL*)aOther->GetStyleData(eStyleStruct_XUL);
         if (xul != otherXUL) {
-          NS_UpdateHint(aHint, xul->CalcDifference(*otherXUL));
+          NS_UpdateHint(hint, xul->CalcDifference(*otherXUL));
         }
       }
     }
 #endif
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleContent* content = (const nsStyleContent*)PeekStyleData(eStyleStruct_Content);
       if (content) {
         const nsStyleContent* otherContent = (const nsStyleContent*)aOther->GetStyleData(eStyleStruct_Content);
         if (content != otherContent) {
-          NS_UpdateHint(aHint, content->CalcDifference(*otherContent));
+          NS_UpdateHint(hint, content->CalcDifference(*otherContent));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleUserInterface* ui = (const nsStyleUserInterface*)PeekStyleData(eStyleStruct_UserInterface);
       if (ui) {
         const nsStyleUserInterface* otherUI = (const nsStyleUserInterface*)aOther->GetStyleData(eStyleStruct_UserInterface);
         if (ui != otherUI) {
-          NS_UpdateHint(aHint, ui->CalcDifference(*otherUI));
+          NS_UpdateHint(hint, ui->CalcDifference(*otherUI));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleVisibility* vis = (const nsStyleVisibility*)PeekStyleData(eStyleStruct_Visibility);
       if (vis) {
         const nsStyleVisibility* otherVis = (const nsStyleVisibility*)aOther->GetStyleData(eStyleStruct_Visibility);
         if (vis != otherVis) {
-          NS_UpdateHint(aHint, vis->CalcDifference(*otherVis));
+          NS_UpdateHint(hint, vis->CalcDifference(*otherVis));
         }
       }
     }
 
 #ifdef MOZ_SVG
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleSVG* svg = (const nsStyleSVG*)PeekStyleData(eStyleStruct_SVG);
       if (svg) {
         const nsStyleSVG* otherSVG = (const nsStyleSVG*)aOther->GetStyleData(eStyleStruct_SVG);
         if (svg != otherSVG) {
-          NS_UpdateHint(aHint, svg->CalcDifference(*otherSVG));
+          NS_UpdateHint(hint, svg->CalcDifference(*otherSVG));
         }
       }
     }
@@ -630,12 +521,12 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, nsChangeHint& aHint
 
     // If the quotes implementation is ever going to change we might not need
     // a framechange here and a reflow should be sufficient.  See bug 35768.
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleQuotes* quotes = (const nsStyleQuotes*)PeekStyleData(eStyleStruct_Quotes);
       if (quotes) {
         const nsStyleQuotes* otherQuotes = (const nsStyleQuotes*)aOther->GetStyleData(eStyleStruct_Quotes);
         if (quotes != otherQuotes) {
-          NS_UpdateHint(aHint, quotes->CalcDifference(*otherQuotes));
+          NS_UpdateHint(hint, quotes->CalcDifference(*otherQuotes));
         }
       }
     }
@@ -646,102 +537,102 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, nsChangeHint& aHint
     // The following structs cause (as their maximal difference) a reflow to occur.
     // REFLOW Structs: Font, Margin, Padding, Border, List, Position, Text, TextReset,
     // Table, TableBorder
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleFont* font = (const nsStyleFont*)PeekStyleData(eStyleStruct_Font);
       if (font) {
         const nsStyleFont* otherFont = (const nsStyleFont*)aOther->GetStyleData(eStyleStruct_Font);
         if (font != otherFont) {
-          NS_UpdateHint(aHint, font->CalcDifference(*otherFont));
+          NS_UpdateHint(hint, font->CalcDifference(*otherFont));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleMargin* margin = (const nsStyleMargin*)PeekStyleData(eStyleStruct_Margin);
       if (margin) {
         const nsStyleMargin* otherMargin = (const nsStyleMargin*)aOther->GetStyleData(eStyleStruct_Margin);
         if (margin != otherMargin) {
-          NS_UpdateHint(aHint, margin->CalcDifference(*otherMargin));
+          NS_UpdateHint(hint, margin->CalcDifference(*otherMargin));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStylePadding* padding = (const nsStylePadding*)PeekStyleData(eStyleStruct_Padding);
       if (padding) {
         const nsStylePadding* otherPadding = (const nsStylePadding*)aOther->GetStyleData(eStyleStruct_Padding);
         if (padding != otherPadding) {
-          NS_UpdateHint(aHint, padding->CalcDifference(*otherPadding));
+          NS_UpdateHint(hint, padding->CalcDifference(*otherPadding));
         }
       }
     }
     
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleBorder* border = (const nsStyleBorder*)PeekStyleData(eStyleStruct_Border);
       if (border) {
         const nsStyleBorder* otherBorder = (const nsStyleBorder*)aOther->GetStyleData(eStyleStruct_Border);
         if (border != otherBorder) {
-          NS_UpdateHint(aHint, border->CalcDifference(*otherBorder));
+          NS_UpdateHint(hint, border->CalcDifference(*otherBorder));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleList* list = (const nsStyleList*)PeekStyleData(eStyleStruct_List);
       if (list) {
         const nsStyleList* otherList = (const nsStyleList*)aOther->GetStyleData(eStyleStruct_List);
         if (list != otherList) {
-          NS_UpdateHint(aHint, list->CalcDifference(*otherList));
+          NS_UpdateHint(hint, list->CalcDifference(*otherList));
         }
       }
     }
     
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStylePosition* pos = (const nsStylePosition*)PeekStyleData(eStyleStruct_Position);
       if (pos) {
         const nsStylePosition* otherPosition = (const nsStylePosition*)aOther->GetStyleData(eStyleStruct_Position);
         if (pos != otherPosition) {
-          NS_UpdateHint(aHint, pos->CalcDifference(*otherPosition));
+          NS_UpdateHint(hint, pos->CalcDifference(*otherPosition));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleText* text = (const nsStyleText*)PeekStyleData(eStyleStruct_Text);
       if (text) {
         const nsStyleText* otherText = (const nsStyleText*)aOther->GetStyleData(eStyleStruct_Text);
         if (text != otherText) {
-          NS_UpdateHint(aHint, text->CalcDifference(*otherText));
+          NS_UpdateHint(hint, text->CalcDifference(*otherText));
         }
       }
     }
     
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleTextReset* text = (const nsStyleTextReset*)PeekStyleData(eStyleStruct_TextReset);
       if (text) {
         const nsStyleTextReset* otherText = (const nsStyleTextReset*)aOther->GetStyleData(eStyleStruct_TextReset);
         if (text != otherText) {
-          NS_UpdateHint(aHint, text->CalcDifference(*otherText));
+          NS_UpdateHint(hint, text->CalcDifference(*otherText));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleTable* table = (const nsStyleTable*)PeekStyleData(eStyleStruct_Table);
       if (table) {
         const nsStyleTable* otherTable = (const nsStyleTable*)aOther->GetStyleData(eStyleStruct_Table);
         if (table != otherTable) {
-          NS_UpdateHint(aHint, table->CalcDifference(*otherTable));
+          NS_UpdateHint(hint, table->CalcDifference(*otherTable));
         }
       }
     }
     
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleTableBorder* table = (const nsStyleTableBorder*)PeekStyleData(eStyleStruct_TableBorder);
       if (table) {
         const nsStyleTableBorder* otherTable = (const nsStyleTableBorder*)aOther->GetStyleData(eStyleStruct_TableBorder);
         if (table != otherTable) {
-          NS_UpdateHint(aHint, table->CalcDifference(*otherTable));
+          NS_UpdateHint(hint, table->CalcDifference(*otherTable));
         }
       }
     }
@@ -752,47 +643,47 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, nsChangeHint& aHint
 
     // The following structs cause (as their maximal difference) a re-render to occur.
     // VISUAL Structs: Color, Background, Outline, UIReset
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleColor* color = (const nsStyleColor*)PeekStyleData(eStyleStruct_Color);
       if (color) {
         const nsStyleColor* otherColor = (const nsStyleColor*)aOther->GetStyleData(eStyleStruct_Color);
         if (color != otherColor) {
-          NS_UpdateHint(aHint, color->CalcDifference(*otherColor));
+          NS_UpdateHint(hint, color->CalcDifference(*otherColor));
         }
       }
     }
 
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleBackground* background = (const nsStyleBackground*)PeekStyleData(eStyleStruct_Background);
       if (background) {
         const nsStyleBackground* otherBackground = (const nsStyleBackground*)aOther->GetStyleData(eStyleStruct_Background);
         if (background != otherBackground) {
-          NS_UpdateHint(aHint, background->CalcDifference(*otherBackground));
+          NS_UpdateHint(hint, background->CalcDifference(*otherBackground));
         }
       }
     }
     
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleOutline* outline = (const nsStyleOutline*)PeekStyleData(eStyleStruct_Outline);
       if (outline) {
         const nsStyleOutline* otherOutline = (const nsStyleOutline*)aOther->GetStyleData(eStyleStruct_Outline);
         if (outline != otherOutline) {
-          NS_UpdateHint(aHint, outline->CalcDifference(*otherOutline));
+          NS_UpdateHint(hint, outline->CalcDifference(*otherOutline));
         }
       }
     }
     
-    if (!NS_IsHintSubset(maxHint, aHint)) {
+    if (!NS_IsHintSubset(maxHint, hint)) {
       const nsStyleUIReset* ui = (const nsStyleUIReset*)PeekStyleData(eStyleStruct_UIReset);
       if (ui) {
         const nsStyleUIReset* otherUI = (const nsStyleUIReset*)aOther->GetStyleData(eStyleStruct_UIReset);
         if (ui != otherUI) {
-          NS_UpdateHint(aHint, ui->CalcDifference(*otherUI));
+          NS_UpdateHint(hint, ui->CalcDifference(*otherUI));
         }
       }
     }
   }
-  return NS_OK;
+  return hint;
 }
 
 #ifdef DEBUG
@@ -802,7 +693,7 @@ void nsStyleContext::List(FILE* out, PRInt32 aIndent)
   PRInt32 ix;
   for (ix = aIndent; --ix >= 0; ) fputs("  ", out);
   fprintf(out, "%p(%d) parent=%p ",
-          (void*)this, mRefCnt.get(), (void *)mParent);
+          (void*)this, mRefCnt, (void *)mParent);
   if (mPseudoTag) {
     nsAutoString  buffer;
     mPseudoTag->ToString(buffer);
@@ -1176,24 +1067,16 @@ nsStyleContext::Destroy()
   presContext->FreeToShell(sizeof(nsStyleContext), this);
 }
 
-NS_EXPORT nsresult
-NS_NewStyleContext(nsIStyleContext** aInstancePtrResult,
-                   nsIStyleContext* aParentContext,
+already_AddRefed<nsStyleContext>
+NS_NewStyleContext(nsStyleContext* aParentContext,
                    nsIAtom* aPseudoTag,
                    nsRuleNode* aRuleNode,
                    nsIPresContext* aPresContext)
 {
-  NS_PRECONDITION(nsnull != aInstancePtrResult, "null ptr");
-  if (nsnull == aInstancePtrResult) {
-    return NS_ERROR_NULL_POINTER;
-  }
-
   nsStyleContext* context = new (aPresContext) nsStyleContext(aParentContext, aPseudoTag, 
                                                               aRuleNode, aPresContext);
-  if (!context) {
-    return NS_ERROR_OUT_OF_MEMORY;
-  }
-
-  return CallQueryInterface(context, aInstancePtrResult);
+  if (context)
+    context->AddRef();
+  return context;
 }
 
diff --git a/mozilla/layout/style/nsStyleContext.h b/mozilla/layout/style/nsStyleContext.h
new file mode 100644
index 00000000000..974f6bb87eb
--- /dev/null
+++ b/mozilla/layout/style/nsStyleContext.h
@@ -0,0 +1,159 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: NPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is 
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1998
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   David Hyatt <hyatt@netscape.com>
+ *   Pierre Phaneuf <pp@ludusdesign.com>
+ *
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the NPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the NPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef _nsStyleContext_h_
+#define _nsStyleContext_h_
+
+#include "nsRuleNode.h"
+
+class nsIPresContext;
+class nsIAtom;
+
+class nsStyleContext
+{
+public:
+  nsStyleContext(nsStyleContext* aParent, nsIAtom* aPseudoTag, 
+                 nsRuleNode* aRuleNode, nsIPresContext* aPresContext);
+  ~nsStyleContext();
+
+  void* operator new(size_t sz, nsIPresContext* aPresContext) CPP_THROW_NEW;
+  void Destroy();
+
+  void AddRef() {
+    ++mRefCnt;
+    NS_LOG_ADDREF(this, mRefCnt, "nsStyleContext", sizeof(nsStyleContext));
+  }
+
+  void Release() {
+    --mRefCnt;
+    NS_LOG_RELEASE(this, mRefCnt, "nsStyleContext");
+    if (mRefCnt == 0) {
+      mRefCnt = 1;
+      Destroy();
+    }
+  }
+
+  nsStyleContext* GetParent() const { return mParent; }
+
+  nsStyleContext* GetFirstChild() const { return mChild; }
+
+  already_AddRefed<nsIAtom> GetPseudoType() const;
+
+  already_AddRefed<nsStyleContext> 
+  FindChildWithRules(const nsIAtom* aPseudoTag, nsRuleNode* aRules);
+
+  PRBool    Equals(const nsStyleContext* aOther) const;
+  PRBool    HasTextDecorations() { return mBits & NS_STYLE_HAS_TEXT_DECORATIONS; };
+
+  void GetBorderPaddingFor(nsStyleBorderPadding& aBorderPadding);
+
+  void SetStyle(nsStyleStructID aSID, nsStyleStruct* aStruct);
+
+  void GetRuleNode(nsRuleNode** aResult) { *aResult = mRuleNode; }
+  void AddStyleBit(const PRUint32& aBit) { mBits |= aBit; }
+  void GetStyleBits(PRUint32* aBits) { *aBits = mBits; }
+
+  const nsStyleStruct* GetStyleData(nsStyleStructID aSID);
+  const nsStyleStruct* PeekStyleData(nsStyleStructID aSID);
+
+  nsStyleStruct* GetUniqueStyleData(nsIPresContext* aPresContext, const nsStyleStructID& aSID);
+
+  void ClearCachedDataForRule(nsIStyleRule* aRule);
+
+  void ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule);
+
+  nsChangeHint CalcStyleDifference(nsStyleContext* aOther);
+
+#ifdef DEBUG
+  void DumpRegressionData(nsIPresContext* aPresContext, FILE* out, PRInt32 aIndent);
+
+  void List(FILE* out, PRInt32 aIndent);
+
+  void SizeOf(nsISizeOfHandler *aSizeOfHandler, PRUint32 &aSize);
+#endif
+
+protected:
+  void AppendChild(nsStyleContext* aChild);
+  void RemoveChild(nsStyleContext* aChild);
+
+  void ApplyStyleFixups(nsIPresContext* aPresContext);
+
+  nsStyleContext* mParent;
+  nsStyleContext* mChild;
+  nsStyleContext* mEmptyChild;
+  nsStyleContext* mPrevSibling;
+  nsStyleContext* mNextSibling;
+
+  // If this style context is for a pseudo-element, the pseudo-element
+  // atom.  Otherwise, null.
+  nsCOMPtr<nsIAtom> mPseudoTag;
+
+  nsRuleNode*             mRuleNode;
+
+  // |mCachedStyleData| points to both structs that are owned by this
+  // style context and structs that are owned by one of this style
+  // context's ancestors (which are indirectly owned since this style
+  // context owns a reference to its parent).  If the bit in |mBits| is
+  // set for a struct, that means that the pointer for that struct is
+  // owned by an ancestor rather than by this style context.
+  nsCachedStyleData       mCachedStyleData; // Our cached style data.
+  PRUint32                mBits; // Which structs are inherited from the
+                                 // parent context.
+  PRUint32                mRefCnt;
+};
+
+already_AddRefed<nsStyleContext>
+NS_NewStyleContext(nsStyleContext* aParentContext,
+                   nsIAtom* aPseudoTag,
+                   nsRuleNode* aRuleNode,
+                   nsIPresContext* aPresContext);
+
+
+// typesafe way to access style data.  See nsStyleStruct.h and also
+// overloaded function in nsIFrame.h.
+template <class T>
+inline void
+GetStyleData(nsStyleContext* aStyleContext, const T** aStyleStruct)
+{
+    *aStyleStruct = NS_STATIC_CAST(const T*,
+                         aStyleContext->GetStyleData(NS_GET_STYLESTRUCTID(T)));
+}
+
+#endif
diff --git a/mozilla/layout/style/nsStyleSet.cpp b/mozilla/layout/style/nsStyleSet.cpp
index cec07984b8f..9e4c35e439a 100644
--- a/mozilla/layout/style/nsStyleSet.cpp
+++ b/mozilla/layout/style/nsStyleSet.cpp
@@ -149,24 +149,27 @@ public:
 
   NS_IMETHOD NotifyStyleSheetStateChanged(PRBool aDisabled);
 
-  virtual nsIStyleContext* ResolveStyleFor(nsIPresContext* aPresContext,
-                                           nsIContent* aContent,
-                                           nsIStyleContext* aParentContext);
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleFor(nsIPresContext* aPresContext,
+                  nsIContent* aContent,
+                  nsStyleContext* aParentContext);
 
-  virtual nsIStyleContext* ResolveStyleForNonElement(
-                                           nsIPresContext* aPresContext,
-                                           nsIStyleContext* aParentContext);
+  virtual already_AddRefed<nsStyleContext>
+  ResolveStyleForNonElement(nsIPresContext* aPresContext,
+                            nsStyleContext* aParentContext);
 
-  virtual nsIStyleContext* ResolvePseudoStyleFor(nsIPresContext* aPresContext,
-                                                 nsIContent* aParentContent,
-                                                 nsIAtom* aPseudoTag,
-                                                 nsIStyleContext* aParentContext,
-                                                 nsICSSPseudoComparator* aComparator = nsnull);
+  virtual already_AddRefed<nsStyleContext>
+  ResolvePseudoStyleFor(nsIPresContext* aPresContext,
+                        nsIContent* aParentContent,
+                        nsIAtom* aPseudoTag,
+                        nsStyleContext* aParentContext,
+                        nsICSSPseudoComparator* aComparator = nsnull);
 
-  virtual nsIStyleContext* ProbePseudoStyleFor(nsIPresContext* aPresContext,
-                                               nsIContent* aParentContent,
-                                               nsIAtom* aPseudoTag,
-                                               nsIStyleContext* aParentContext);
+  virtual already_AddRefed<nsStyleContext>
+  ProbePseudoStyleFor(nsIPresContext* aPresContext,
+                      nsIContent* aParentContent,
+                      nsIAtom* aPseudoTag,
+                      nsStyleContext* aParentContext);
 
   NS_IMETHOD Shutdown();
 
@@ -189,7 +192,7 @@ public:
   
   virtual nsresult AddRuleNodeMapping(nsRuleNode* aRuleNode);
 
-  virtual nsresult ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule, nsIStyleContext* aContext);
+  virtual nsresult ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule, nsStyleContext* aContext);
 
   virtual nsresult GetStyleFrameConstruction(nsIStyleFrameConstruction** aResult) {
     *aResult = mFrameConstructor;
@@ -197,10 +200,10 @@ public:
     return NS_OK;
   }
 
-  NS_IMETHOD ReParentStyleContext(nsIPresContext* aPresContext,
-                                  nsIStyleContext* aStyleContext, 
-                                  nsIStyleContext* aNewParentContext,
-                                  nsIStyleContext** aNewStyleContext);
+  virtual already_AddRefed<nsStyleContext>
+  ReParentStyleContext(nsIPresContext* aPresContext,
+                       nsStyleContext* aStyleContext, 
+                       nsStyleContext* aNewParentContext);
 
   NS_IMETHOD HasStateDependentStyle(nsIPresContext* aPresContext,
                                     nsIContent*     aContent,
@@ -335,9 +338,9 @@ protected:
   void WalkRuleProcessors(nsISupportsArrayEnumFunc aFunc,
                           RuleProcessorData* aData);
 
-  nsIStyleContext* GetContext(nsIPresContext* aPresContext, 
-                              nsIStyleContext* aParentContext,
-                              nsIAtom* aPseudoTag);
+  already_AddRefed<nsStyleContext> GetContext(nsIPresContext* aPresContext, 
+                                              nsStyleContext* aParentContext,
+                                              nsIAtom* aPseudoTag);
 
 #ifdef DEBUG
   void  List(FILE* out, PRInt32 aIndent, nsISupportsArray* aSheets);
@@ -999,15 +1002,16 @@ EnumRulesMatching(nsISupports* aProcessor, void* aData)
  * generation.  (It works for cousins of the same generation since
  * |aParentContext| could itself be a shared context.)
  */
-nsIStyleContext* StyleSetImpl::GetContext(nsIPresContext* aPresContext, 
-                                          nsIStyleContext* aParentContext, 
-                                          nsIAtom* aPseudoTag)
+already_AddRefed<nsStyleContext>
+StyleSetImpl::GetContext(nsIPresContext* aPresContext, 
+                         nsStyleContext* aParentContext, 
+                         nsIAtom* aPseudoTag)
 {
-  nsIStyleContext* result = nsnull;
+  nsStyleContext* result = nsnull;
   nsRuleNode* ruleNode = mRuleWalker->GetCurrentNode();
       
   if (aParentContext)
-    aParentContext->FindChildWithRules(aPseudoTag, ruleNode, result);
+    result = aParentContext->FindChildWithRules(aPseudoTag, ruleNode).get();
 
 #ifdef NOISY_DEBUG
   if (result)
@@ -1017,8 +1021,8 @@ nsIStyleContext* StyleSetImpl::GetContext(nsIPresContext* aPresContext,
 #endif
 
   if (!result)
-    NS_NewStyleContext(&result, aParentContext, aPseudoTag, ruleNode,
-                       aPresContext);
+    result = NS_NewStyleContext(aParentContext, aPseudoTag, ruleNode,
+                                aPresContext).get();
 
   return result;
 }
@@ -1150,14 +1154,15 @@ void StyleSetImpl::EnsureRuleWalker(nsIPresContext* aPresContext)
   mRuleWalker = new nsRuleWalker(mRuleTree);
 }
 
-nsIStyleContext* StyleSetImpl::ResolveStyleFor(nsIPresContext* aPresContext,
-                                               nsIContent* aContent,
-                                               nsIStyleContext* aParentContext)
+already_AddRefed<nsStyleContext>
+StyleSetImpl::ResolveStyleFor(nsIPresContext* aPresContext,
+                              nsIContent* aContent,
+                              nsStyleContext* aParentContext)
 {
   MOZ_TIMER_DEBUGLOG(("Start: StyleSetImpl::ResolveStyleFor(), this=%p\n", this));
   STYLESET_START_TIMER(NS_TIMER_STYLE_RESOLUTION);
 
-  nsIStyleContext*  result = nsnull;
+  nsStyleContext*  result = nsnull;
 
   NS_ASSERTION(aContent, "must have content");
   NS_ASSERTION(aPresContext, "must have pres context");
@@ -1175,7 +1180,7 @@ nsIStyleContext* StyleSetImpl::ResolveStyleFor(nsIPresContext* aPresContext,
       aPresContext->GetMedium(getter_AddRefs(medium));
       RulesMatchingData data(aPresContext, medium, aContent, mRuleWalker);
       FileRules(EnumRulesMatching, &data);
-      result = GetContext(aPresContext, aParentContext, nsnull);
+      result = GetContext(aPresContext, aParentContext, nsnull).get();
      
       // Now reset the walker back to the root of the tree.
       mRuleWalker->Reset();
@@ -1187,14 +1192,14 @@ nsIStyleContext* StyleSetImpl::ResolveStyleFor(nsIPresContext* aPresContext,
   return result;
 }
 
-nsIStyleContext* StyleSetImpl::ResolveStyleForNonElement(
-                                               nsIPresContext* aPresContext,
-                                               nsIStyleContext* aParentContext)
+already_AddRefed<nsStyleContext>
+StyleSetImpl::ResolveStyleForNonElement(nsIPresContext* aPresContext,
+                                        nsStyleContext* aParentContext)
 {
   MOZ_TIMER_DEBUGLOG(("Start: StyleSetImpl::ResolveStyleForNonElement(), this=%p\n", this));
   STYLESET_START_TIMER(NS_TIMER_STYLE_RESOLUTION);
 
-  nsIStyleContext* result = nsnull;
+  nsStyleContext* result = nsnull;
 
   NS_ASSERTION(aPresContext, "must have pres context");
 
@@ -1206,7 +1211,7 @@ nsIStyleContext* StyleSetImpl::ResolveStyleForNonElement(
         mOverrideRuleProcessors) {
       EnsureRuleWalker(aPresContext);
       result = GetContext(aPresContext, aParentContext,
-                          nsCSSAnonBoxes::mozNonElement);
+                          nsCSSAnonBoxes::mozNonElement).get();
       NS_ASSERTION(mRuleWalker->AtRoot(), "rule walker must be at root");
     }
   }
@@ -1242,16 +1247,17 @@ EnumPseudoRulesMatching(nsISupports* aProcessor, void* aData)
   return PR_TRUE;
 }
 
-nsIStyleContext* StyleSetImpl::ResolvePseudoStyleFor(nsIPresContext* aPresContext,
-                                                     nsIContent* aParentContent,
-                                                     nsIAtom* aPseudoTag,
-                                                     nsIStyleContext* aParentContext,
-                                                     nsICSSPseudoComparator* aComparator)
+already_AddRefed<nsStyleContext>
+StyleSetImpl::ResolvePseudoStyleFor(nsIPresContext* aPresContext,
+                                    nsIContent* aParentContent,
+                                    nsIAtom* aPseudoTag,
+                                    nsStyleContext* aParentContext,
+                                    nsICSSPseudoComparator* aComparator)
 {
   MOZ_TIMER_DEBUGLOG(("Start: StyleSetImpl::ResolvePseudoStyleFor(), this=%p\n", this));
   STYLESET_START_TIMER(NS_TIMER_STYLE_RESOLUTION);
 
-  nsIStyleContext*  result = nsnull;
+  nsStyleContext*  result = nsnull;
 
   NS_ASSERTION(aPseudoTag, "must have pseudo tag");
   NS_ASSERTION(aPresContext, "must have pres context");
@@ -1272,7 +1278,7 @@ nsIStyleContext* StyleSetImpl::ResolvePseudoStyleFor(nsIPresContext* aPresContex
                                    aPseudoTag, aComparator, mRuleWalker);
       FileRules(EnumPseudoRulesMatching, &data);
 
-      result = GetContext(aPresContext, aParentContext, aPseudoTag);
+      result = GetContext(aPresContext, aParentContext, aPseudoTag).get();
      
       // Now reset the walker back to the root of the tree.
       mRuleWalker->Reset();
@@ -1284,15 +1290,16 @@ nsIStyleContext* StyleSetImpl::ResolvePseudoStyleFor(nsIPresContext* aPresContex
   return result;
 }
 
-nsIStyleContext* StyleSetImpl::ProbePseudoStyleFor(nsIPresContext* aPresContext,
-                                                   nsIContent* aParentContent,
-                                                   nsIAtom* aPseudoTag,
-                                                   nsIStyleContext* aParentContext)
+already_AddRefed<nsStyleContext>
+StyleSetImpl::ProbePseudoStyleFor(nsIPresContext* aPresContext,
+                                  nsIContent* aParentContent,
+                                  nsIAtom* aPseudoTag,
+                                  nsStyleContext* aParentContext)
 {
   MOZ_TIMER_DEBUGLOG(("Start: StyleSetImpl::ProbePseudoStyleFor(), this=%p\n", this));
   STYLESET_START_TIMER(NS_TIMER_STYLE_RESOLUTION);
 
-  nsIStyleContext*  result = nsnull;
+  nsStyleContext*  result = nsnull;
 
   NS_ASSERTION(aPseudoTag, "must have pseudo tag");
   NS_ASSERTION(aPresContext, "must have pres context");
@@ -1314,7 +1321,7 @@ nsIStyleContext* StyleSetImpl::ProbePseudoStyleFor(nsIPresContext* aPresContext,
       FileRules(EnumPseudoRulesMatching, &data);
 
       if (!mRuleWalker->AtRoot())
-        result = GetContext(aPresContext, aParentContext, aPseudoTag);
+        result = GetContext(aPresContext, aParentContext, aPseudoTag).get();
  
       // Now reset the walker back to the root of the tree.
       mRuleWalker->Reset();
@@ -1397,7 +1404,7 @@ StyleSetImpl::ClearCachedDataInRuleTree(nsIStyleRule* aInlineStyleRule)
 }
 
 nsresult
-StyleSetImpl::ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule, nsIStyleContext* aContext)
+StyleSetImpl::ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule, nsStyleContext* aContext)
 {
   // XXXdwh.  If we're willing to *really* optimize this
   // invalidation, we could only invalidate the struct data
@@ -1450,8 +1457,7 @@ StyleSetImpl::ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule,
     nsIFrame* rootFrame;
     shell->GetRootFrame(&rootFrame);
     if (rootFrame) {
-      nsCOMPtr<nsIStyleContext> rootContext;
-      rootFrame->GetStyleContext(getter_AddRefs(rootContext));
+      nsStyleContext* rootContext = rootFrame->GetStyleContext();
       if (rootContext)
         rootContext->ClearStyleData(aPresContext, aRule);
     }
@@ -1460,46 +1466,38 @@ StyleSetImpl::ClearStyleData(nsIPresContext* aPresContext, nsIStyleRule* aRule,
   return NS_OK;
 }
 
-NS_IMETHODIMP
+already_AddRefed<nsStyleContext>
 StyleSetImpl::ReParentStyleContext(nsIPresContext* aPresContext,
-                                   nsIStyleContext* aStyleContext, 
-                                   nsIStyleContext* aNewParentContext,
-                                   nsIStyleContext** aNewStyleContext)
+                                   nsStyleContext* aStyleContext, 
+                                   nsStyleContext* aNewParentContext)
 {
   NS_ASSERTION(aPresContext, "must have pres context");
   NS_ASSERTION(aStyleContext, "must have style context");
-  NS_ASSERTION(aNewStyleContext, "must have new style context");
 
-  nsresult result = NS_ERROR_NULL_POINTER;
-
-  if (aPresContext && aStyleContext && aNewStyleContext) {
-    nsCOMPtr<nsIStyleContext> oldParent = aStyleContext->GetParent();
+  if (aPresContext && aStyleContext) {
+    nsStyleContext* oldParent = aStyleContext->GetParent();
 
     if (oldParent == aNewParentContext) {
-      result = NS_OK;
-      NS_ADDREF(aStyleContext);   // for return
-      *aNewStyleContext = aStyleContext;
+      aStyleContext->AddRef();
+      return aStyleContext;
     }
     else {  // really a new parent
-      nsIStyleContext*  newChild = nsnull;
-      nsCOMPtr<nsIAtom>  pseudoTag;
-      aStyleContext->GetPseudoType(*getter_AddRefs(pseudoTag));
+      nsStyleContext*  newChild = nsnull;
+      nsCOMPtr<nsIAtom>  pseudoTag = aStyleContext->GetPseudoType();
 
       nsRuleNode* ruleNode;
       aStyleContext->GetRuleNode(&ruleNode);
-      if (aNewParentContext) {
-        result = aNewParentContext->FindChildWithRules(pseudoTag, ruleNode, newChild);
-      }
-      if (newChild) { // new parent already has one
-        *aNewStyleContext = newChild;
-      }
+      if (aNewParentContext)
+        newChild = aNewParentContext->FindChildWithRules(pseudoTag, ruleNode).get();
+      if (newChild) // new parent already has one
+        return newChild;
       else {  // need to make one in the new parent
-        result = NS_NewStyleContext(aNewStyleContext, aNewParentContext, pseudoTag,
-                                    ruleNode, aPresContext);
+        return NS_NewStyleContext(aNewParentContext, pseudoTag, ruleNode,
+                                  aPresContext);
       }
     }
   }
-  return result;
+  return nsnull;
 }
 
 struct StatefulData : public StateRuleProcessorData {
@@ -1764,8 +1762,7 @@ void StyleSetImpl::List(FILE* out, PRInt32 aIndent)
 
 void StyleSetImpl::ListContexts(nsIFrame* aRootFrame, FILE* out, PRInt32 aIndent)
 {
-  nsCOMPtr<nsIStyleContext> sc;
-  aRootFrame->GetStyleContext(getter_AddRefs(sc));
+  nsStyleContext* sc = aRootFrame->GetStyleContext();
   if (sc)
     sc->List(out, aIndent);
 }
diff --git a/mozilla/layout/style/nsStyleStruct.cpp b/mozilla/layout/style/nsStyleStruct.cpp
index 49e83428e16..2ab1fa3fc69 100644
--- a/mozilla/layout/style/nsStyleStruct.cpp
+++ b/mozilla/layout/style/nsStyleStruct.cpp
@@ -78,8 +78,7 @@ inline nscoord CalcSideFor(const nsIFrame* aFrame, const nsStyleCoord& aCoord,
       nsIFrame* parentFrame;
       aFrame->GetParent(&parentFrame);  // XXX may not be direct parent...
       if (nsnull != parentFrame) {
-        nsIStyleContext* parentContext;
-        parentFrame->GetStyleContext(&parentContext);
+        nsStyleContext* parentContext = parentFrame->GetStyleContext();
         if (nsnull != parentContext) {
           nsMargin  parentSpacing;
           switch (aSpacing) {
@@ -111,7 +110,6 @@ inline nscoord CalcSideFor(const nsIFrame* aFrame, const nsStyleCoord& aCoord,
             case NS_SIDE_RIGHT:   result = parentSpacing.right;  break;
             case NS_SIDE_BOTTOM:  result = parentSpacing.bottom; break;
           }
-          NS_RELEASE(parentContext);
         }
       }
       break;
diff --git a/mozilla/layout/style/nsStyleStruct.h b/mozilla/layout/style/nsStyleStruct.h
index dd99d7931b8..92935245f44 100644
--- a/mozilla/layout/style/nsStyleStruct.h
+++ b/mozilla/layout/style/nsStyleStruct.h
@@ -1219,7 +1219,7 @@ inline nsBorderEdges::nsBorderEdges()
 
 // typesafe mechanisms for accessing style data, global function
 // templates |GetStyleData(nsIFrame*, const T**)| and
-// |GetStyleData(nsIStyleContext*, const T**)|, where T is derived from
-// nsStyleStruct, are located in nsIStyleContext.h and nsIFrame.h
+// |GetStyleData(nsStyleContext*, const T**)|, where T is derived from
+// nsStyleStruct, are located in nsStyleContext.h and nsIFrame.h
 
 #endif /* nsStyleStruct_h___ */
diff --git a/mozilla/layout/style/nsStyleUtil.h b/mozilla/layout/style/nsStyleUtil.h
index 5a33ee77bdd..6393e157d98 100644
--- a/mozilla/layout/style/nsStyleUtil.h
+++ b/mozilla/layout/style/nsStyleUtil.h
@@ -42,7 +42,6 @@
 #include "nsIPresContext.h"
 #include "nsILinkHandler.h" // for nsLinkState
 
-class nsIStyleContext;
 struct nsStyleBackground;
 
 enum nsFontSizeType {
diff --git a/mozilla/layout/svg/base/src/nsSVGForeignObjectFrame.cpp b/mozilla/layout/svg/base/src/nsSVGForeignObjectFrame.cpp
index 017883e315a..3f74f46dc52 100644
--- a/mozilla/layout/svg/base/src/nsSVGForeignObjectFrame.cpp
+++ b/mozilla/layout/svg/base/src/nsSVGForeignObjectFrame.cpp
@@ -79,7 +79,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Reflow(nsIPresContext*          aPresContext,
@@ -281,7 +281,7 @@ NS_IMETHODIMP
 nsSVGForeignObjectFrame::Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow)
 {
   nsresult rv;
diff --git a/mozilla/layout/svg/base/src/nsSVGGFrame.cpp b/mozilla/layout/svg/base/src/nsSVGGFrame.cpp
index ee7dc71bb76..32573cae4fb 100644
--- a/mozilla/layout/svg/base/src/nsSVGGFrame.cpp
+++ b/mozilla/layout/svg/base/src/nsSVGGFrame.cpp
@@ -90,7 +90,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
 
@@ -183,7 +183,7 @@ NS_IMETHODIMP
 nsSVGGFrame::Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow)
 {
   nsresult rv;
diff --git a/mozilla/layout/svg/base/src/nsSVGGenericContainerFrame.cpp b/mozilla/layout/svg/base/src/nsSVGGenericContainerFrame.cpp
index 9e875fea734..0b6f1cda99f 100644
--- a/mozilla/layout/svg/base/src/nsSVGGenericContainerFrame.cpp
+++ b/mozilla/layout/svg/base/src/nsSVGGenericContainerFrame.cpp
@@ -89,7 +89,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD  AttributeChanged(nsIPresContext* aPresContext,
@@ -168,7 +168,7 @@ NS_IMETHODIMP
 nsSVGGenericContainerFrame::Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow)
 {
   nsresult rv;
diff --git a/mozilla/layout/svg/base/src/nsSVGGraphicFrame.cpp b/mozilla/layout/svg/base/src/nsSVGGraphicFrame.cpp
index 4d9e329d7e4..d2b05984264 100644
--- a/mozilla/layout/svg/base/src/nsSVGGraphicFrame.cpp
+++ b/mozilla/layout/svg/base/src/nsSVGGraphicFrame.cpp
@@ -92,7 +92,7 @@ NS_IMETHODIMP
 nsSVGGraphicFrame::Init(nsIPresContext*  aPresContext,
                      nsIContent*      aContent,
                      nsIFrame*        aParent,
-                     nsIStyleContext* aContext,
+                     nsStyleContext*  aContext,
                      nsIFrame*        aPrevInFlow)
 {
   nsresult rv;
diff --git a/mozilla/layout/svg/base/src/nsSVGGraphicFrame.h b/mozilla/layout/svg/base/src/nsSVGGraphicFrame.h
index 4300eb18515..a940f97d391 100644
--- a/mozilla/layout/svg/base/src/nsSVGGraphicFrame.h
+++ b/mozilla/layout/svg/base/src/nsSVGGraphicFrame.h
@@ -77,7 +77,7 @@ public:
   Init(nsIPresContext*  aPresContext,
        nsIContent*      aContent,
        nsIFrame*        aParent,
-       nsIStyleContext* aContext,
+       nsStyleContext*  aContext,
        nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD  AttributeChanged(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/svg/base/src/nsSVGOuterSVGFrame.cpp b/mozilla/layout/svg/base/src/nsSVGOuterSVGFrame.cpp
index 65d5b568296..cbf5a49647b 100644
--- a/mozilla/layout/svg/base/src/nsSVGOuterSVGFrame.cpp
+++ b/mozilla/layout/svg/base/src/nsSVGOuterSVGFrame.cpp
@@ -79,7 +79,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
   
   NS_IMETHOD Reflow(nsIPresContext*          aPresContext,
@@ -279,7 +279,7 @@ NS_IMETHODIMP
 nsSVGOuterSVGFrame::Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow)
 {
   nsresult rv;
diff --git a/mozilla/layout/tables/nsTableCellFrame.cpp b/mozilla/layout/tables/nsTableCellFrame.cpp
index 3d7d4b7f04e..7b3c7e1d7b9 100644
--- a/mozilla/layout/tables/nsTableCellFrame.cpp
+++ b/mozilla/layout/tables/nsTableCellFrame.cpp
@@ -41,7 +41,7 @@
 #include "nsTableFrame.h"
 #include "nsTableRowGroupFrame.h"
 #include "nsReflowPath.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIPresContext.h"
 #include "nsIRenderingContext.h"
@@ -116,7 +116,7 @@ NS_IMETHODIMP
 nsTableCellFrame::Init(nsIPresContext*  aPresContext,
                        nsIContent*      aContent,
                        nsIFrame*        aParent,
-                       nsIStyleContext* aContext,
+                       nsStyleContext*  aContext,
                        nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
diff --git a/mozilla/layout/tables/nsTableCellFrame.h b/mozilla/layout/tables/nsTableCellFrame.h
index 79c6abdb838..4db09980812 100644
--- a/mozilla/layout/tables/nsTableCellFrame.h
+++ b/mozilla/layout/tables/nsTableCellFrame.h
@@ -41,7 +41,7 @@
 #include "nscore.h"
 #include "nsHTMLContainerFrame.h"
 #include "nsTableRowFrame.h"  // need to actually include this here to inline GetRowIndex
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIPercentHeightObserver.h"
 #include "nsLayoutAtoms.h"
 
@@ -85,7 +85,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
 #ifdef ACCESSIBILITY
diff --git a/mozilla/layout/tables/nsTableColFrame.cpp b/mozilla/layout/tables/nsTableColFrame.cpp
index 3bf577d733b..4a12e9da353 100644
--- a/mozilla/layout/tables/nsTableColFrame.cpp
+++ b/mozilla/layout/tables/nsTableColFrame.cpp
@@ -37,7 +37,7 @@
 #include "nsCOMPtr.h"
 #include "nsTableColFrame.h"
 #include "nsContainerFrame.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIPresContext.h"
 #include "nsHTMLAtoms.h"
@@ -116,8 +116,7 @@ nsStyleCoord nsTableColFrame::GetStyleWidth() const
       eStyleUnit_Inherit == styleWidth.GetUnit()) {
     nsIFrame* parent;
     GetParent(&parent);
-    nsCOMPtr<nsIStyleContext> styleContext;
-    parent->GetStyleContext(getter_AddRefs(styleContext)); 
+    nsStyleContext* styleContext = parent->GetStyleContext();
     if (styleContext) {
       position = (nsStylePosition*)styleContext->GetStyleData(eStyleStruct_Position);
       styleWidth = position->mWidth;
@@ -269,7 +268,7 @@ NS_IMETHODIMP
 nsTableColFrame::Init(nsIPresContext*  aPresContext,
                       nsIContent*      aContent,
                       nsIFrame*        aParent,
-                      nsIStyleContext* aContext,
+                      nsStyleContext*  aContext,
                       nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
diff --git a/mozilla/layout/tables/nsTableColFrame.h b/mozilla/layout/tables/nsTableColFrame.h
index 505a84b3726..280efa9933b 100644
--- a/mozilla/layout/tables/nsTableColFrame.h
+++ b/mozilla/layout/tables/nsTableColFrame.h
@@ -107,7 +107,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Paint(nsIPresContext*      aPresContext,
diff --git a/mozilla/layout/tables/nsTableColGroupFrame.cpp b/mozilla/layout/tables/nsTableColGroupFrame.cpp
index ce3d2d53bb2..9221c4540ca 100644
--- a/mozilla/layout/tables/nsTableColGroupFrame.cpp
+++ b/mozilla/layout/tables/nsTableColGroupFrame.cpp
@@ -40,7 +40,7 @@
 #include "nsIHTMLTableColElement.h"
 #include "nsIDOMHTMLTableColElement.h"
 #include "nsReflowPath.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIPresContext.h"
 #include "nsIHTMLContent.h"
@@ -722,7 +722,7 @@ NS_IMETHODIMP
 nsTableColGroupFrame::Init(nsIPresContext*  aPresContext,
                            nsIContent*      aContent,
                            nsIFrame*        aParent,
-                           nsIStyleContext* aContext,
+                           nsStyleContext*  aContext,
                            nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
diff --git a/mozilla/layout/tables/nsTableColGroupFrame.h b/mozilla/layout/tables/nsTableColGroupFrame.h
index ffcb9cf2dff..d0f0f556882 100644
--- a/mozilla/layout/tables/nsTableColGroupFrame.h
+++ b/mozilla/layout/tables/nsTableColGroupFrame.h
@@ -73,7 +73,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD SetInitialChildList(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/tables/nsTableFrame.cpp b/mozilla/layout/tables/nsTableFrame.cpp
index eb09677fa04..13d4ee48758 100644
--- a/mozilla/layout/tables/nsTableFrame.cpp
+++ b/mozilla/layout/tables/nsTableFrame.cpp
@@ -39,7 +39,7 @@
 #include "nsVoidArray.h"
 #include "nsTableFrame.h"
 #include "nsIRenderingContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIContent.h"
 #include "nsCellMap.h"
@@ -76,7 +76,7 @@
 #include "nsIFrameManager.h"
 #include "nsCSSRendering.h"
 #include "nsLayoutErrors.h"
-
+#include "nsAutoPtr.h"
 
 
 /********************************************************************************
@@ -247,7 +247,7 @@ NS_IMETHODIMP
 nsTableFrame::Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
@@ -377,8 +377,8 @@ PRBool
 nsTableFrame::PageBreakAfter(nsIFrame& aSourceFrame,
                              nsIFrame* aNextFrame)
 {
-  nsCOMPtr<nsIStyleContext> sourceContext;
-  aSourceFrame.GetStyleContext(getter_AddRefs(sourceContext)); NS_ENSURE_TRUE(sourceContext, PR_FALSE);
+  nsStyleContext* sourceContext = aSourceFrame.GetStyleContext();
+  NS_ENSURE_TRUE(sourceContext, PR_FALSE);
   const nsStyleDisplay* display = (const nsStyleDisplay*)
     sourceContext->GetStyleData(eStyleStruct_Display);         NS_ENSURE_TRUE(display, PR_FALSE); 
   // don't allow a page break after a repeated header
@@ -387,8 +387,8 @@ nsTableFrame::PageBreakAfter(nsIFrame& aSourceFrame,
   }
 
   if (aNextFrame) {
-    nsCOMPtr<nsIStyleContext> nextContext;
-    aNextFrame->GetStyleContext(getter_AddRefs(nextContext));  NS_ENSURE_TRUE(nextContext, PR_FALSE);
+    nsStyleContext* nextContext = aNextFrame->GetStyleContext();
+    NS_ENSURE_TRUE(nextContext, PR_FALSE);
     display = (const nsStyleDisplay*)
       nextContext->GetStyleData(eStyleStruct_Display);         NS_ENSURE_TRUE(display, PR_FALSE); 
     // don't allow a page break before a repeated footer
@@ -860,11 +860,10 @@ nsTableFrame::CreateAnonymousColGroupFrame(nsIPresContext&     aPresContext,
   nsCOMPtr<nsIContent> colGroupContent;
   GetContent(getter_AddRefs(colGroupContent));
 
-  nsCOMPtr<nsIStyleContext> colGroupStyle;
-  aPresContext.ResolvePseudoStyleContextFor(colGroupContent,
-                                            nsCSSAnonBoxes::tableColGroup,
-                                            mStyleContext,
-                                            getter_AddRefs(colGroupStyle));        
+  nsRefPtr<nsStyleContext> colGroupStyle;
+  colGroupStyle = aPresContext.ResolvePseudoStyleContextFor(colGroupContent,
+                                                            nsCSSAnonBoxes::tableColGroup,
+                                                            mStyleContext);
   // Create a col group frame
   nsIFrame* newFrame;
   nsCOMPtr<nsIPresShell> presShell;
@@ -967,21 +966,22 @@ nsTableFrame::CreateAnonymousColFrames(nsIPresContext&       aPresContext,
 
   for (PRInt32 childX = startIndex; childX <= lastIndex; childX++) {
     nsCOMPtr<nsIContent> iContent;
-    nsCOMPtr<nsIStyleContext> styleContext;
-    nsCOMPtr<nsIStyleContext> parentStyleContext;
+    nsRefPtr<nsStyleContext> styleContext;
+    nsStyleContext* parentStyleContext;
 
     if ((aColType == eColAnonymousCol) && aPrevFrameIn) {
       // a col due to a span in a previous col uses the style context of the col
-      aPrevFrameIn->GetStyleContext(getter_AddRefs(styleContext)); 
+      styleContext = aPrevFrameIn->GetStyleContext();
       // fix for bugzilla bug 54454: get the content from the prevFrame 
       aPrevFrameIn->GetContent(getter_AddRefs(iContent));
     }
     else {
       // all other anonymous cols use a pseudo style context of the col group
       aColGroupFrame.GetContent(getter_AddRefs(iContent));
-      aColGroupFrame.GetStyleContext(getter_AddRefs(parentStyleContext));
-      aPresContext.ResolvePseudoStyleContextFor(iContent, nsCSSAnonBoxes::tableCol,
-                                                parentStyleContext, getter_AddRefs(styleContext));
+      parentStyleContext = aColGroupFrame.GetStyleContext();
+      styleContext = aPresContext.ResolvePseudoStyleContextFor(iContent,
+                                                               nsCSSAnonBoxes::tableCol,
+                                                               parentStyleContext);
     }
     // ASSERTION to check for bug 54454 sneaking back in...
     NS_ASSERTION(iContent, "null content in CreateAnonymousColFrames");
@@ -2867,7 +2867,7 @@ nsTableFrame::GetBCBorder(nsIPresContext& aPresContext,
 static
 void GetSeparateModelBorderPadding(nsIPresContext&          aPresContext,
                                    const nsHTMLReflowState* aReflowState,
-                                   nsIStyleContext&         aStyleContext,
+                                   nsStyleContext&          aStyleContext,
                                    nsMargin&                aBorderPadding)
 {
   const nsStyleBorder* border =
@@ -3775,7 +3775,7 @@ UpdateCol(nsTableFrame&           aTableFrame,
 }
 
 PRBool 
-nsTableFrame::IsPctHeight(nsIStyleContext* aStyleContext) 
+nsTableFrame::IsPctHeight(nsStyleContext* aStyleContext) 
 {
   PRBool result = PR_FALSE;
   if (aStyleContext) {
@@ -4164,10 +4164,8 @@ PRBool
 nsTableFrame::IsAutoHeight()
 {
   PRBool isAuto = PR_TRUE;  // the default
-  nsCOMPtr<nsIStyleContext> styleContext;
-  GetStyleContext(getter_AddRefs(styleContext)); 
 
-  nsStylePosition* position = (nsStylePosition*)styleContext->GetStyleData(eStyleStruct_Position);
+  nsStylePosition* position = (nsStylePosition*)mStyleContext->GetStyleData(eStyleStruct_Position);
 
   switch (position->mHeight.GetUnit()) {
     case eStyleUnit_Auto:         // specified auto width
@@ -5171,8 +5169,8 @@ GetStyleInfo(const nsIFrame&  aFrame,
   PRBool transparent, foreground;
   styleData->GetBorderColor(aSide, aColor, transparent, foreground);
   if (foreground) {
-    nsCOMPtr<nsIStyleContext> styleContext;
-    aFrame.GetStyleContext(getter_AddRefs(styleContext)); if(!styleContext) ABORT0();
+    nsStyleContext* styleContext = aFrame.GetStyleContext();
+    if(!styleContext) ABORT0();
     const nsStyleColor* colorStyle = (const nsStyleColor*)styleContext->GetStyleData(eStyleStruct_Color);
     aColor = colorStyle->mColor;
   }
diff --git a/mozilla/layout/tables/nsTableFrame.h b/mozilla/layout/tables/nsTableFrame.h
index c355542df8c..fef8f6c3f41 100644
--- a/mozilla/layout/tables/nsTableFrame.h
+++ b/mozilla/layout/tables/nsTableFrame.h
@@ -42,7 +42,6 @@
 #include "nsHTMLContainerFrame.h"
 #include "nsStyleCoord.h"
 #include "nsStyleConsts.h"
-#include "nsIStyleContext.h"
 #include "nsITableLayout.h"
 #include "nsTableColFrame.h"
 #include "nsTableColGroupFrame.h"
@@ -56,6 +55,7 @@ class nsTableRowFrame;
 class nsTableColGroupFrame;
 class nsITableLayoutStrategy;
 class nsHTMLValue;
+class nsStyleContext;
 
 struct nsTableReflowState;
 struct nsStylePosition;
@@ -203,7 +203,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
 
@@ -293,7 +293,7 @@ public:
                                       nsIAtom*        aChildType);
   PRBool IsAutoWidth(PRBool* aIsPctWidth = nsnull);
   PRBool IsAutoHeight();
-  static PRBool IsPctHeight(nsIStyleContext* aStyleContext);
+  static PRBool IsPctHeight(nsStyleContext* aStyleContext);
   
   /** @return PR_TRUE if aDisplayType represents a rowgroup of any sort
     * (header, footer, or body)
diff --git a/mozilla/layout/tables/nsTableOuterFrame.cpp b/mozilla/layout/tables/nsTableOuterFrame.cpp
index ec74829dc95..355b0e716fb 100644
--- a/mozilla/layout/tables/nsTableOuterFrame.cpp
+++ b/mozilla/layout/tables/nsTableOuterFrame.cpp
@@ -38,7 +38,7 @@
 #include "nsTableOuterFrame.h"
 #include "nsTableFrame.h"
 #include "nsHTMLReflowCommand.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIPresContext.h"
 #include "nsIRenderingContext.h"
@@ -166,7 +166,7 @@ NS_IMETHODIMP
 nsTableOuterFrame::Init(nsIPresContext*  aPresContext,
                    nsIContent*           aContent,
                    nsIFrame*             aParent,
-                   nsIStyleContext*      aContext,
+                   nsStyleContext*       aContext,
                    nsIFrame*             aPrevInFlow)
 {
   nsresult rv = nsHTMLContainerFrame::Init(aPresContext, aContent, aParent, 
@@ -1231,8 +1231,7 @@ nsTableOuterFrame::IsAutoWidth(nsIFrame& aTableOrCaption,
     *aIsPctWidth = PR_FALSE;
   }
 
-  nsCOMPtr<nsIStyleContext> styleContext;
-  aTableOrCaption.GetStyleContext(getter_AddRefs(styleContext)); 
+  nsStyleContext* styleContext = aTableOrCaption.GetStyleContext();
 
   nsStylePosition* position = (nsStylePosition*)styleContext->GetStyleData(eStyleStruct_Position);
 
@@ -1877,8 +1876,7 @@ static PRBool
 IsPctHeight(nsIFrame* aFrame)
 {
   if (aFrame) {
-    nsCOMPtr<nsIStyleContext> styleContext;
-    aFrame->GetStyleContext(getter_AddRefs(styleContext)); 
+    nsStyleContext* styleContext = aFrame->GetStyleContext();
     nsStylePosition* position = (nsStylePosition*)styleContext->GetStyleData(eStyleStruct_Position);
     if (eStyleUnit_Percent == position->mHeight.GetUnit()) {
       float percent = position->mHeight.GetPercentValue();
diff --git a/mozilla/layout/tables/nsTableOuterFrame.h b/mozilla/layout/tables/nsTableOuterFrame.h
index ed72a539aa3..351bfe535ba 100644
--- a/mozilla/layout/tables/nsTableOuterFrame.h
+++ b/mozilla/layout/tables/nsTableOuterFrame.h
@@ -91,7 +91,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
diff --git a/mozilla/layout/tables/nsTableRowFrame.cpp b/mozilla/layout/tables/nsTableRowFrame.cpp
index 70d6baf0246..138bc5ca288 100644
--- a/mozilla/layout/tables/nsTableRowFrame.cpp
+++ b/mozilla/layout/tables/nsTableRowFrame.cpp
@@ -39,7 +39,7 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresShell.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIHTMLContent.h"
 #include "nsHTMLAtoms.h"
@@ -190,7 +190,7 @@ NS_IMETHODIMP
 nsTableRowFrame::Init(nsIPresContext*  aPresContext,
                       nsIContent*      aContent,
                       nsIFrame*        aParent,
-                      nsIStyleContext* aContext,
+                      nsStyleContext*  aContext,
                       nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
diff --git a/mozilla/layout/tables/nsTableRowFrame.h b/mozilla/layout/tables/nsTableRowFrame.h
index bf08c32e7a4..aa46d78af04 100644
--- a/mozilla/layout/tables/nsTableRowFrame.h
+++ b/mozilla/layout/tables/nsTableRowFrame.h
@@ -69,7 +69,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD SetInitialChildList(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/tables/nsTableRowGroupFrame.cpp b/mozilla/layout/tables/nsTableRowGroupFrame.cpp
index 5a1b208c9bb..e03dc0f4371 100644
--- a/mozilla/layout/tables/nsTableRowGroupFrame.cpp
+++ b/mozilla/layout/tables/nsTableRowGroupFrame.cpp
@@ -41,7 +41,7 @@
 #include "nsTableCellFrame.h"
 #include "nsIRenderingContext.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsIContent.h"
 #include "nsIView.h"
@@ -1874,7 +1874,7 @@ NS_IMETHODIMP
 nsTableRowGroupFrame::Init(nsIPresContext*  aPresContext,
                            nsIContent*      aContent,
                            nsIFrame*        aParent,
-                           nsIStyleContext* aContext,
+                           nsStyleContext*  aContext,
                            nsIFrame*        aPrevInFlow)
 {
   nsresult  rv;
diff --git a/mozilla/layout/tables/nsTableRowGroupFrame.h b/mozilla/layout/tables/nsTableRowGroupFrame.h
index 6fc4bc81e64..1b82f15fdec 100644
--- a/mozilla/layout/tables/nsTableRowGroupFrame.h
+++ b/mozilla/layout/tables/nsTableRowGroupFrame.h
@@ -117,7 +117,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD AppendFrames(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/xul/base/src/nsBox.cpp b/mozilla/layout/xul/base/src/nsBox.cpp
index 432c92822bb..608602dc885 100644
--- a/mozilla/layout/xul/base/src/nsBox.cpp
+++ b/mozilla/layout/xul/base/src/nsBox.cpp
@@ -40,7 +40,6 @@
 #include "nsBoxLayoutState.h"
 #include "nsBox.h"
 #include "nsBoxFrame.h"
-#include "nsIStyleContext.h"
 #include "nsIPresContext.h"
 #include "nsCOMPtr.h"
 #include "nsIContent.h"
diff --git a/mozilla/layout/xul/base/src/nsBoxFrame.cpp b/mozilla/layout/xul/base/src/nsBoxFrame.cpp
index b7e194286eb..e32e7b167dc 100644
--- a/mozilla/layout/xul/base/src/nsBoxFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsBoxFrame.cpp
@@ -65,7 +65,7 @@
 
 #include "nsBoxLayoutState.h"
 #include "nsBoxFrame.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIPresContext.h"
 #include "nsCOMPtr.h"
 #include "nsUnitConversion.h"
@@ -254,7 +254,7 @@ NS_IMETHODIMP
 nsBoxFrame::Init(nsIPresContext*  aPresContext,
                  nsIContent*      aContent,
                  nsIFrame*        aParent,
-                 nsIStyleContext* aContext,
+                 nsStyleContext*  aContext,
                  nsIFrame*        aPrevInFlow)
 {
   SetParent(aParent);
@@ -2481,7 +2481,7 @@ nsBoxFrame::GetFrameSizeWithMargin(nsIBox* aBox, nsSize& aSize)
 nsresult
 nsBoxFrame::CreateViewForFrame(nsIPresContext*  aPresContext,
                                nsIFrame*        aFrame,
-                               nsIStyleContext* aStyleContext,
+                               nsStyleContext*  aStyleContext,
                                PRBool           aForce)
 {
   nsIView* view;
@@ -2514,14 +2514,12 @@ nsBoxFrame::CreateViewForFrame(nsIPresContext*  aPresContext,
     
     // See if the frame is a scrolled frame
     if (!aForce) {
-      nsIAtom*  pseudoTag;
-      aStyleContext->GetPseudoType(pseudoTag);
+      nsCOMPtr<nsIAtom> pseudoTag = aStyleContext->GetPseudoType();
       if (pseudoTag == nsCSSAnonBoxes::scrolledContent) {
         NS_FRAME_LOG(NS_FRAME_TRACE_CALLS,
           ("nsBoxFrame::CreateViewForFrame: scrolled frame=%p", aFrame));
         aForce = PR_TRUE;
       }
-      NS_IF_RELEASE(pseudoTag);
     }
 
     if (aForce) {
diff --git a/mozilla/layout/xul/base/src/nsBoxFrame.h b/mozilla/layout/xul/base/src/nsBoxFrame.h
index 71cd172c5b9..c445d5bc5c2 100644
--- a/mozilla/layout/xul/base/src/nsBoxFrame.h
+++ b/mozilla/layout/xul/base/src/nsBoxFrame.h
@@ -135,7 +135,7 @@ public:
   NS_IMETHOD  Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        asPrevInFlow);
 
  
@@ -194,7 +194,7 @@ public:
  
   static nsresult CreateViewForFrame(nsIPresContext* aPresContext,
                                      nsIFrame* aChild,
-                                     nsIStyleContext* aStyleContext,
+                                     nsStyleContext* aStyleContext,
                                      PRBool aForce);
 
   NS_IMETHOD  Paint(nsIPresContext*      aPresContext,
diff --git a/mozilla/layout/xul/base/src/nsBoxToBlockAdaptor.cpp b/mozilla/layout/xul/base/src/nsBoxToBlockAdaptor.cpp
index f87708af87d..2b432c6d7e5 100644
--- a/mozilla/layout/xul/base/src/nsBoxToBlockAdaptor.cpp
+++ b/mozilla/layout/xul/base/src/nsBoxToBlockAdaptor.cpp
@@ -44,7 +44,7 @@
 
 #include "nsBoxLayoutState.h"
 #include "nsBoxFrame.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIPresContext.h"
 #include "nsCOMPtr.h"
 #include "nsUnitConversion.h"
@@ -180,10 +180,9 @@ nsBoxToBlockAdaptor::SetParentBox(nsIBox* aParent)
         mFrame->GetView(context, &view);
 
         if (!view) {
-           nsCOMPtr<nsIStyleContext> style;
-           mFrame->GetStyleContext(getter_AddRefs(style));
-           nsHTMLContainerFrame::CreateViewForFrame(context,mFrame,style,nsnull,PR_TRUE); 
-           mFrame->GetView(context, &view);
+          nsStyleContext* style = mFrame->GetStyleContext();
+          nsHTMLContainerFrame::CreateViewForFrame(context,mFrame,style,nsnull,PR_TRUE); 
+          mFrame->GetView(context, &view);
         }
 
         nsCOMPtr<nsIWidget> widget;
diff --git a/mozilla/layout/xul/base/src/nsDeckFrame.cpp b/mozilla/layout/xul/base/src/nsDeckFrame.cpp
index 03f745c96f8..65ca916dcf2 100644
--- a/mozilla/layout/xul/base/src/nsDeckFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsDeckFrame.cpp
@@ -43,7 +43,7 @@
 //
 
 #include "nsDeckFrame.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIPresContext.h"
 #include "nsIContent.h"
 #include "nsCOMPtr.h"
@@ -115,10 +115,9 @@ nsDeckFrame::CreateWidget(nsIPresContext* aPresContext, nsIBox* aBox)
   frame->GetView(aPresContext, &view);
   
   if (!view) {
-     nsCOMPtr<nsIStyleContext> context;
-     frame->GetStyleContext(getter_AddRefs(context));
-     nsHTMLContainerFrame::CreateViewForFrame(aPresContext,frame,context,nsnull,PR_TRUE); 
-     frame->GetView(aPresContext, &view);
+    nsStyleContext* context = frame->GetStyleContext();
+    nsHTMLContainerFrame::CreateViewForFrame(aPresContext,frame,context,nsnull,PR_TRUE); 
+    frame->GetView(aPresContext, &view);
   }
 
   nsCOMPtr<nsIWidget> widget;
@@ -204,7 +203,7 @@ NS_IMETHODIMP
 nsDeckFrame::Init(nsIPresContext*  aPresContext,
                     nsIContent*      aContent,
                     nsIFrame*        aParent,
-                    nsIStyleContext* aStyleContext,
+                    nsStyleContext*  aStyleContext,
                     nsIFrame*        aPrevInFlow)
 {
   nsresult  rv = nsBoxFrame::Init(aPresContext, aContent,
diff --git a/mozilla/layout/xul/base/src/nsDeckFrame.h b/mozilla/layout/xul/base/src/nsDeckFrame.h
index ac2503e4c7e..8e5d5cf85e0 100644
--- a/mozilla/layout/xul/base/src/nsDeckFrame.h
+++ b/mozilla/layout/xul/base/src/nsDeckFrame.h
@@ -95,7 +95,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                 nsIContent*      aContent,
                 nsIFrame*        aParent,
-                nsIStyleContext* aContext,
+                nsStyleContext*  aContext,
                 nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD ChildrenMustHaveWidgets(PRBool& aMust);
diff --git a/mozilla/layout/xul/base/src/nsGroupBoxFrame.cpp b/mozilla/layout/xul/base/src/nsGroupBoxFrame.cpp
index bf1cb48d833..94140dd32ea 100644
--- a/mozilla/layout/xul/base/src/nsGroupBoxFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsGroupBoxFrame.cpp
@@ -39,7 +39,7 @@
 
 #include "nsBoxFrame.h"
 #include "nsCSSRendering.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 
 class nsGroupBoxFrame : public nsBoxFrame {
 public:
diff --git a/mozilla/layout/xul/base/src/nsImageBoxFrame.cpp b/mozilla/layout/xul/base/src/nsImageBoxFrame.cpp
index 732718bcc08..2e354051b5e 100644
--- a/mozilla/layout/xul/base/src/nsImageBoxFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsImageBoxFrame.cpp
@@ -47,7 +47,7 @@
 #include "nsIFontMetrics.h"
 #include "nsHTMLAtoms.h"
 #include "nsXULAtoms.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsCOMPtr.h"
 #include "nsIPresContext.h"
@@ -66,7 +66,6 @@
 #include "nsIHTMLContent.h"
 #include "nsIDocument.h"
 #include "nsIHTMLDocument.h"
-#include "nsIStyleContext.h"
 #include "nsStyleConsts.h"
 #include "nsImageMap.h"
 #include "nsILinkHandler.h"
@@ -85,7 +84,6 @@
 #include "nsTextFragment.h"
 #include "nsIDOMHTMLMapElement.h"
 #include "nsIStyleSet.h"
-#include "nsIStyleContext.h"
 #include "nsBoxLayoutState.h"
 #include "nsIDOMDocument.h"
 #include "nsIEventQueueService.h"
@@ -324,7 +322,7 @@ NS_IMETHODIMP
 nsImageBoxFrame::Init(nsIPresContext*  aPresContext,
                           nsIContent*      aContent,
                           nsIFrame*        aParent,
-                          nsIStyleContext* aContext,
+                          nsStyleContext*  aContext,
                           nsIFrame*        aPrevInFlow)
 {
   if (!mListener) {
diff --git a/mozilla/layout/xul/base/src/nsImageBoxFrame.h b/mozilla/layout/xul/base/src/nsImageBoxFrame.h
index 70453082d1b..af342b66153 100644
--- a/mozilla/layout/xul/base/src/nsImageBoxFrame.h
+++ b/mozilla/layout/xul/base/src/nsImageBoxFrame.h
@@ -80,7 +80,7 @@ public:
   NS_IMETHOD  Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        asPrevInFlow);
 
   NS_IMETHOD AttributeChanged(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/xul/base/src/nsLeafBoxFrame.cpp b/mozilla/layout/xul/base/src/nsLeafBoxFrame.cpp
index 11420b648b6..60c6ee0a70e 100644
--- a/mozilla/layout/xul/base/src/nsLeafBoxFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsLeafBoxFrame.cpp
@@ -51,7 +51,7 @@
 #include "nsXULAtoms.h"
 #include "nsIPresContext.h"
 #include "nsIRenderingContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIContent.h"
 #include "nsINameSpaceManager.h"
 #include "nsBoxLayoutState.h"
@@ -103,7 +103,7 @@ NS_IMETHODIMP
 nsLeafBoxFrame::Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow)
 {
   nsresult  rv = nsLeafFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/xul/base/src/nsLeafBoxFrame.h b/mozilla/layout/xul/base/src/nsLeafBoxFrame.h
index bf5482a270e..ab32fd81ab3 100644
--- a/mozilla/layout/xul/base/src/nsLeafBoxFrame.h
+++ b/mozilla/layout/xul/base/src/nsLeafBoxFrame.h
@@ -74,7 +74,7 @@ public:
   NS_IMETHOD  Init(nsIPresContext*  aPresContext,
                nsIContent*      aContent,
                nsIFrame*        aParent,
-               nsIStyleContext* aContext,
+               nsStyleContext*  aContext,
                nsIFrame*        asPrevInFlow);
 
   NS_IMETHOD GetFrameForPoint(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/xul/base/src/nsListBoxBodyFrame.cpp b/mozilla/layout/xul/base/src/nsListBoxBodyFrame.cpp
index e8f5783da3f..06e329458a0 100644
--- a/mozilla/layout/xul/base/src/nsListBoxBodyFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsListBoxBodyFrame.cpp
@@ -61,11 +61,12 @@
 #include "nsIScrollableFrame.h"
 #include "nsIScrollbarFrame.h"
 #include "nsIScrollableView.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIRenderingContext.h"
 #include "nsIDeviceContext.h"
 #include "nsIFontMetrics.h"
 #include "nsITimer.h"
+#include "nsAutoPtr.h"
 
 /////////////// nsListScrollSmoother //////////////////
 
@@ -225,7 +226,7 @@ NS_INTERFACE_MAP_END_INHERITING(nsBoxFrame)
 
 NS_IMETHODIMP
 nsListBoxBodyFrame::Init(nsIPresContext* aPresContext, nsIContent* aContent,
-                         nsIFrame* aParent, nsIStyleContext* aContext, nsIFrame* aPrevInFlow)
+                         nsIFrame* aParent, nsStyleContext* aContext, nsIFrame* aPrevInFlow)
 {
   nsresult rv = nsBoxFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
 
@@ -747,9 +748,9 @@ nsListBoxBodyFrame::ComputeIntrinsicWidth(nsBoxLayoutState& aBoxLayoutState)
   nsCOMPtr<nsIContent> firstRowContent(do_QueryInterface(firstRowEl));
 
   if (firstRowContent) {
-    nsCOMPtr<nsIStyleContext> styleContext;
-    aBoxLayoutState.GetPresContext()->ResolveStyleContextFor(firstRowContent, nsnull,
-                                                             getter_AddRefs(styleContext));
+    nsRefPtr<nsStyleContext> styleContext;
+    styleContext = aBoxLayoutState.GetPresContext()->ResolveStyleContextFor(firstRowContent,
+                                                                            nsnull);
 
     nscoord width = 0;
     nsMargin margin(0,0,0,0);
diff --git a/mozilla/layout/xul/base/src/nsListBoxBodyFrame.h b/mozilla/layout/xul/base/src/nsListBoxBodyFrame.h
index b491e0ec927..de3d9e1182a 100644
--- a/mozilla/layout/xul/base/src/nsListBoxBodyFrame.h
+++ b/mozilla/layout/xul/base/src/nsListBoxBodyFrame.h
@@ -75,7 +75,7 @@ public:
   
   // nsIFrame
   NS_IMETHOD Init(nsIPresContext* aPresContext, nsIContent* aContent,
-                  nsIFrame* aParent, nsIStyleContext* aContext, nsIFrame* aPrevInFlow);
+                  nsIFrame* aParent, nsStyleContext* aContext, nsIFrame* aPrevInFlow);
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
   NS_IMETHOD AttributeChanged(nsIPresContext* aPresContext, nsIContent* aChild,
                                  PRInt32 aNameSpaceID, nsIAtom* aAttribute, PRInt32 aModType, PRInt32 aHint) ;
diff --git a/mozilla/layout/xul/base/src/nsMenuBarFrame.cpp b/mozilla/layout/xul/base/src/nsMenuBarFrame.cpp
index b03ce63d7ce..a1ccd6cf3ba 100644
--- a/mozilla/layout/xul/base/src/nsMenuBarFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsMenuBarFrame.cpp
@@ -46,7 +46,7 @@
 #include "prtypes.h"
 #include "nsIAtom.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsCSSRendering.h"
 #include "nsINameSpaceManager.h"
 #include "nsIDocument.h"
@@ -137,7 +137,7 @@ NS_IMETHODIMP
 nsMenuBarFrame::Init(nsIPresContext*  aPresContext,
                      nsIContent*      aContent,
                      nsIFrame*        aParent,
-                     nsIStyleContext* aContext,
+                     nsStyleContext*  aContext,
                      nsIFrame*        aPrevInFlow)
 {
   nsresult  rv = nsBoxFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/xul/base/src/nsMenuBarFrame.h b/mozilla/layout/xul/base/src/nsMenuBarFrame.h
index 348b5d9d0a9..cd2721b8572 100644
--- a/mozilla/layout/xul/base/src/nsMenuBarFrame.h
+++ b/mozilla/layout/xul/base/src/nsMenuBarFrame.h
@@ -104,7 +104,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
diff --git a/mozilla/layout/xul/base/src/nsMenuFrame.cpp b/mozilla/layout/xul/base/src/nsMenuFrame.cpp
index 1a9ac36aba2..358f3ff612e 100644
--- a/mozilla/layout/xul/base/src/nsMenuFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsMenuFrame.cpp
@@ -49,7 +49,7 @@
 #include "nsIAtom.h"
 #include "nsIPresContext.h"
 #include "nsIPresShell.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsCSSRendering.h"
 #include "nsINameSpaceManager.h"
 #include "nsLayoutAtoms.h"
@@ -183,7 +183,7 @@ NS_IMETHODIMP
 nsMenuFrame::Init(nsIPresContext*  aPresContext,
                      nsIContent*      aContent,
                      nsIFrame*        aParent,
-                     nsIStyleContext* aContext,
+                     nsStyleContext*  aContext,
                      nsIFrame*        aPrevInFlow)
 {
   mPresContext = aPresContext; // Don't addref it.  Our lifetime is shorter.
diff --git a/mozilla/layout/xul/base/src/nsMenuFrame.h b/mozilla/layout/xul/base/src/nsMenuFrame.h
index 093cc09c11e..2d79d8ae11a 100644
--- a/mozilla/layout/xul/base/src/nsMenuFrame.h
+++ b/mozilla/layout/xul/base/src/nsMenuFrame.h
@@ -88,7 +88,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD SetDebug(nsBoxLayoutState& aState, PRBool aDebug);
diff --git a/mozilla/layout/xul/base/src/nsMenuPopupFrame.cpp b/mozilla/layout/xul/base/src/nsMenuPopupFrame.cpp
index 79935fc3266..51474b54ec5 100644
--- a/mozilla/layout/xul/base/src/nsMenuPopupFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsMenuPopupFrame.cpp
@@ -47,7 +47,7 @@
 #include "prtypes.h"
 #include "nsIAtom.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsCSSRendering.h"
 #include "nsINameSpaceManager.h"
 #include "nsIViewManager.h"
@@ -168,7 +168,7 @@ NS_IMETHODIMP
 nsMenuPopupFrame::Init(nsIPresContext*  aPresContext,
                        nsIContent*      aContent,
                        nsIFrame*        aParent,
-                       nsIStyleContext* aContext,
+                       nsStyleContext*  aContext,
                        nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsBoxFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/xul/base/src/nsMenuPopupFrame.h b/mozilla/layout/xul/base/src/nsMenuPopupFrame.h
index 143131a74bc..f4db9dfc753 100644
--- a/mozilla/layout/xul/base/src/nsMenuPopupFrame.h
+++ b/mozilla/layout/xul/base/src/nsMenuPopupFrame.h
@@ -119,7 +119,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD AttributeChanged(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/xul/base/src/nsNativeScrollbarFrame.cpp b/mozilla/layout/xul/base/src/nsNativeScrollbarFrame.cpp
index fa42e74a676..a76caf1df8d 100644
--- a/mozilla/layout/xul/base/src/nsNativeScrollbarFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsNativeScrollbarFrame.cpp
@@ -101,7 +101,7 @@ nsNativeScrollbarFrame::~nsNativeScrollbarFrame ( )
 //
 NS_IMETHODIMP
 nsNativeScrollbarFrame::Init(nsIPresContext* aPresContext, nsIContent* aContent,
-                               nsIFrame* aParent, nsIStyleContext* aContext, nsIFrame* aPrevInFlow)
+                               nsIFrame* aParent, nsStyleContext* aContext, nsIFrame* aPrevInFlow)
 {
   nsresult  rv = nsBoxFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
 
diff --git a/mozilla/layout/xul/base/src/nsNativeScrollbarFrame.h b/mozilla/layout/xul/base/src/nsNativeScrollbarFrame.h
index 675327e9c0d..48bbbf51f12 100644
--- a/mozilla/layout/xul/base/src/nsNativeScrollbarFrame.h
+++ b/mozilla/layout/xul/base/src/nsNativeScrollbarFrame.h
@@ -54,7 +54,7 @@ class nsISupportsArray;
 class nsIPresShell;
 class nsIPresContext;
 class nsIContent;
-class nsIStyleContext;
+class nsStyleContext;
 
 nsresult NS_NewNativeScrollbarFrame(nsIPresShell* aPresShell, nsIFrame** aResult) ;
 
@@ -72,7 +72,7 @@ public:
 #endif
 
   NS_IMETHOD Init(nsIPresContext* aPresContext, nsIContent* aContent,
-                    nsIFrame* aParent, nsIStyleContext* aContext, nsIFrame* aPrevInFlow);
+                    nsIFrame* aParent, nsStyleContext* aContext, nsIFrame* aPrevInFlow);
            
   // nsIFrame overrides
   NS_IMETHOD AttributeChanged(nsIPresContext* aPresContext, nsIContent* aChild,
diff --git a/mozilla/layout/xul/base/src/nsPopupSetFrame.cpp b/mozilla/layout/xul/base/src/nsPopupSetFrame.cpp
index 3fa5f8ff79c..f7c9695440d 100644
--- a/mozilla/layout/xul/base/src/nsPopupSetFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsPopupSetFrame.cpp
@@ -48,7 +48,7 @@
 #include "prtypes.h"
 #include "nsIAtom.h"
 #include "nsIPresContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsCSSRendering.h"
 #include "nsINameSpaceManager.h"
 #include "nsLayoutAtoms.h"
@@ -154,7 +154,7 @@ NS_IMETHODIMP
 nsPopupSetFrame::Init(nsIPresContext*  aPresContext,
                      nsIContent*      aContent,
                      nsIFrame*        aParent,
-                     nsIStyleContext* aContext,
+                     nsStyleContext*  aContext,
                      nsIFrame*        aPrevInFlow)
 {
   mPresContext = aPresContext; // Don't addref it.  Our lifetime is shorter.
diff --git a/mozilla/layout/xul/base/src/nsPopupSetFrame.h b/mozilla/layout/xul/base/src/nsPopupSetFrame.h
index 2ffd7029574..5ed550ded8d 100644
--- a/mozilla/layout/xul/base/src/nsPopupSetFrame.h
+++ b/mozilla/layout/xul/base/src/nsPopupSetFrame.h
@@ -75,7 +75,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
     // nsIBox
diff --git a/mozilla/layout/xul/base/src/nsResizerFrame.cpp b/mozilla/layout/xul/base/src/nsResizerFrame.cpp
index 66812dae9b1..9321d45669a 100644
--- a/mozilla/layout/xul/base/src/nsResizerFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsResizerFrame.cpp
@@ -87,7 +87,7 @@ nsResizerFrame::nsResizerFrame(nsIPresShell* aPresShell)
 NS_IMETHODIMP  nsResizerFrame::Init(nsIPresContext*  aPresContext,
                 nsIContent*      aContent,
                 nsIFrame*        aParent,
-                nsIStyleContext* aContext,
+                nsStyleContext*  aContext,
                 nsIFrame*        asPrevInFlow)
 {
 	nsresult rv = nsTitleBarFrame::Init(aPresContext, aContent, aParent, aContext, asPrevInFlow);
diff --git a/mozilla/layout/xul/base/src/nsResizerFrame.h b/mozilla/layout/xul/base/src/nsResizerFrame.h
index 3f8d006c2f6..97f57c4f895 100644
--- a/mozilla/layout/xul/base/src/nsResizerFrame.h
+++ b/mozilla/layout/xul/base/src/nsResizerFrame.h
@@ -69,7 +69,7 @@ public:
   NS_IMETHOD  Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        asPrevInFlow);
   
   NS_IMETHOD AttributeChanged(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/xul/base/src/nsScrollBoxFrame.cpp b/mozilla/layout/xul/base/src/nsScrollBoxFrame.cpp
index f7e2fd2062e..299a367b1fc 100644
--- a/mozilla/layout/xul/base/src/nsScrollBoxFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsScrollBoxFrame.cpp
@@ -101,7 +101,7 @@ NS_IMETHODIMP
 nsScrollBoxFrame::Init(nsIPresContext*  aPresContext,
                     nsIContent*      aContent,
                     nsIFrame*        aParent,
-                    nsIStyleContext* aStyleContext,
+                    nsStyleContext*  aStyleContext,
                     nsIFrame*        aPrevInFlow)
 {
   nsresult  rv = nsBoxFrame::Init(aPresContext, aContent,
@@ -138,8 +138,7 @@ nsScrollBoxFrame::SetUpScrolledFrame(nsIPresContext* aPresContext)
      return;
 
   // create a view if we don't already have one.
-  nsCOMPtr<nsIStyleContext> context;
-  frame->GetStyleContext(getter_AddRefs(context));
+  nsStyleContext* context = frame->GetStyleContext();
   nsHTMLContainerFrame::CreateViewForFrame(aPresContext, frame,
                                            context, nsnull, PR_TRUE);
 
@@ -827,7 +826,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow);
 
   NS_DECL_NSITIMERCALLBACK
@@ -861,7 +860,7 @@ NS_IMETHODIMP
 nsAutoRepeatBoxFrame::Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow)
 {
   mPresContext = aPresContext;
diff --git a/mozilla/layout/xul/base/src/nsScrollBoxFrame.h b/mozilla/layout/xul/base/src/nsScrollBoxFrame.h
index 15022537996..d75d6f35d0b 100644
--- a/mozilla/layout/xul/base/src/nsScrollBoxFrame.h
+++ b/mozilla/layout/xul/base/src/nsScrollBoxFrame.h
@@ -57,7 +57,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   // Called to set the one and only child frame. Returns NS_ERROR_INVALID_ARG
diff --git a/mozilla/layout/xul/base/src/nsScrollbarFrame.cpp b/mozilla/layout/xul/base/src/nsScrollbarFrame.cpp
index 5b7a275580c..420225947e3 100644
--- a/mozilla/layout/xul/base/src/nsScrollbarFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsScrollbarFrame.cpp
@@ -81,7 +81,7 @@ NS_IMETHODIMP
 nsScrollbarFrame::Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow)
 {
   nsresult  rv = nsBoxFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/xul/base/src/nsScrollbarFrame.h b/mozilla/layout/xul/base/src/nsScrollbarFrame.h
index 1970c0f8f8b..e9a05249677 100644
--- a/mozilla/layout/xul/base/src/nsScrollbarFrame.h
+++ b/mozilla/layout/xul/base/src/nsScrollbarFrame.h
@@ -93,7 +93,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD  IsPercentageBase(PRBool& aBase) const;
diff --git a/mozilla/layout/xul/base/src/nsSliderFrame.cpp b/mozilla/layout/xul/base/src/nsSliderFrame.cpp
index f9e6ac4e4b5..6619563695b 100644
--- a/mozilla/layout/xul/base/src/nsSliderFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsSliderFrame.cpp
@@ -44,7 +44,7 @@
 //
 
 #include "nsSliderFrame.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIPresContext.h"
 #include "nsIContent.h"
 #include "nsCOMPtr.h"
@@ -113,7 +113,7 @@ NS_IMETHODIMP
 nsSliderFrame::Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow)
 {
   nsresult  rv = nsBoxFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/xul/base/src/nsSliderFrame.h b/mozilla/layout/xul/base/src/nsSliderFrame.h
index 373a3ebba92..2225ba9eb78 100644
--- a/mozilla/layout/xul/base/src/nsSliderFrame.h
+++ b/mozilla/layout/xul/base/src/nsSliderFrame.h
@@ -177,7 +177,7 @@ public:
      NS_IMETHOD  Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        asPrevInFlow);
 
 
diff --git a/mozilla/layout/xul/base/src/nsSplitterFrame.cpp b/mozilla/layout/xul/base/src/nsSplitterFrame.cpp
index 438e4300995..bb47b921ff6 100644
--- a/mozilla/layout/xul/base/src/nsSplitterFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsSplitterFrame.cpp
@@ -66,7 +66,7 @@
 #include "nsHTMLParts.h"
 #include "nsILookAndFeel.h"
 #include "nsIPresShell.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsWidgetsCID.h"
 #include "nsBoxLayoutState.h"
 #include "nsIXBLService.h"
@@ -74,7 +74,7 @@
 #include "nsHTMLContainerFrame.h"
 #include "nsINodeInfo.h"
 #include "nsGUIEvent.h"
-
+#include "nsAutoPtr.h"
 #include "nsContentCID.h"
 
 const PRInt32 kMaxZ = 0x7fffffff; //XXX: Shouldn't there be a define somewhere for MaxInt for PRInt32
@@ -327,7 +327,7 @@ NS_IMETHODIMP
 nsSplitterFrame::Init(nsIPresContext*  aPresContext,
               nsIContent*      aContent,
               nsIFrame*        aParent,
-              nsIStyleContext* aContext,
+              nsStyleContext*  aContext,
               nsIFrame*        aPrevInFlow)
 {
 /* make it real time drag for now due to problems
@@ -345,7 +345,7 @@ nsSplitterFrame::Init(nsIPresContext*  aPresContext,
   if (aParent)
     CallQueryInterface(aParent, &boxParent);
   // |newContext| to Release the reference after the call to nsBoxFrame::Init
-  nsCOMPtr<nsIStyleContext> newContext;
+  nsRefPtr<nsStyleContext> newContext;
   if (boxParent) {
     PRBool isHorizontal;
     boxParent->GetOrientation(isHorizontal);
@@ -355,9 +355,8 @@ nsSplitterFrame::Init(nsIPresContext*  aPresContext,
       if (str.IsEmpty()) {
         aContent->SetAttr(kNameSpaceID_None, nsXULAtoms::orient,
                           NS_LITERAL_STRING("vertical"), PR_FALSE);
-        nsCOMPtr<nsIStyleContext> parent = aContext->GetParent();
-        aPresContext->ResolveStyleContextFor(aContent, parent,
-                                             getter_AddRefs(newContext));
+        nsStyleContext* parent = aContext->GetParent();
+        newContext = aPresContext->ResolveStyleContextFor(aContent, parent);
         aContext = newContext;
       }
     }
diff --git a/mozilla/layout/xul/base/src/nsSplitterFrame.h b/mozilla/layout/xul/base/src/nsSplitterFrame.h
index aa3fb1570a3..f457730bdb5 100644
--- a/mozilla/layout/xul/base/src/nsSplitterFrame.h
+++ b/mozilla/layout/xul/base/src/nsSplitterFrame.h
@@ -74,7 +74,7 @@ public:
   NS_IMETHOD Init(nsIPresContext*  aPresContext,
                   nsIContent*      aContent,
                   nsIFrame*        aParent,
-                  nsIStyleContext* aContext,
+                  nsStyleContext*  aContext,
                   nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD GetCursor(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/xul/base/src/nsStackFrame.cpp b/mozilla/layout/xul/base/src/nsStackFrame.cpp
index 3659d2a9156..b73398a345f 100644
--- a/mozilla/layout/xul/base/src/nsStackFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsStackFrame.cpp
@@ -43,7 +43,7 @@
 //
 
 #include "nsStackFrame.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIPresContext.h"
 #include "nsIContent.h"
 #include "nsCOMPtr.h"
@@ -107,7 +107,9 @@ nsStackFrame::GetFrameForPoint(nsIPresContext* aPresContext,
   GetInset(im);
   nsMargin border(0,0,0,0);
   nsStyleBorderPadding  bPad;
-  aFrame->GetStyle(eStyleStruct_BorderPaddingShortcut, (nsStyleStruct&)bPad);
+  nsStyleContext* styleContext;
+  aFrame->GetStyleContext(&styleContext);
+  styleContext->GetBorderPaddingFor(bPad);
   bPad.GetBorderPadding(borderPadding);
   r.Deflate(im);
   r.Deflate(border);    
diff --git a/mozilla/layout/xul/base/src/nsTextBoxFrame.cpp b/mozilla/layout/xul/base/src/nsTextBoxFrame.cpp
index 02bf02faad4..61ab5be66bf 100644
--- a/mozilla/layout/xul/base/src/nsTextBoxFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsTextBoxFrame.cpp
@@ -53,7 +53,7 @@
 #include "nsXULAtoms.h"
 #include "nsIPresContext.h"
 #include "nsIRenderingContext.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIContent.h"
 #include "nsINameSpaceManager.h"
 #include "nsBoxLayoutState.h"
@@ -167,7 +167,7 @@ NS_IMETHODIMP
 nsTextBoxFrame::Init(nsIPresContext*  aPresContext,
                      nsIContent*      aContent,
                      nsIFrame*        aParent,
-                     nsIStyleContext* aContext,
+                     nsStyleContext*  aContext,
                      nsIFrame*        aPrevInFlow)
 {
     nsresult rv = nsTextBoxFrameSuper::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
@@ -352,7 +352,7 @@ nsTextBoxFrame::PaintTitle(nsIPresContext*      aPresContext,
     nscolor overColor;
     nscolor underColor;
     nscolor strikeColor;
-    nsCOMPtr<nsIStyleContext> context = mStyleContext;
+    nsStyleContext* context = mStyleContext;
   
     PRUint8 decorations = NS_STYLE_TEXT_DECORATION_NONE; // Begin with no decorations
     PRUint8 decorMask = NS_STYLE_TEXT_DECORATION_UNDERLINE | NS_STYLE_TEXT_DECORATION_OVERLINE |
diff --git a/mozilla/layout/xul/base/src/nsTextBoxFrame.h b/mozilla/layout/xul/base/src/nsTextBoxFrame.h
index 7279351a252..cbea0d2ad8f 100644
--- a/mozilla/layout/xul/base/src/nsTextBoxFrame.h
+++ b/mozilla/layout/xul/base/src/nsTextBoxFrame.h
@@ -61,7 +61,7 @@ public:
   NS_IMETHOD  Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        asPrevInFlow);
 
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
diff --git a/mozilla/layout/xul/base/src/nsTitleBarFrame.cpp b/mozilla/layout/xul/base/src/nsTitleBarFrame.cpp
index f79e24bd988..c984e679b00 100644
--- a/mozilla/layout/xul/base/src/nsTitleBarFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsTitleBarFrame.cpp
@@ -83,7 +83,7 @@ nsTitleBarFrame::nsTitleBarFrame(nsIPresShell* aPresShell)
 NS_IMETHODIMP  nsTitleBarFrame::Init(nsIPresContext*  aPresContext,
                 nsIContent*      aContent,
                 nsIFrame*        aParent,
-                nsIStyleContext* aContext,
+                nsStyleContext*  aContext,
                 nsIFrame*        asPrevInFlow)
 {
 	nsresult rv = nsBoxFrame::Init(aPresContext, aContent, aParent, aContext, asPrevInFlow);
diff --git a/mozilla/layout/xul/base/src/nsTitleBarFrame.h b/mozilla/layout/xul/base/src/nsTitleBarFrame.h
index fc6032156a8..f89df084d82 100644
--- a/mozilla/layout/xul/base/src/nsTitleBarFrame.h
+++ b/mozilla/layout/xul/base/src/nsTitleBarFrame.h
@@ -51,7 +51,7 @@ public:
   NS_IMETHOD  Init(nsIPresContext*  aPresContext,
                    nsIContent*      aContent,
                    nsIFrame*        aParent,
-                   nsIStyleContext* aContext,
+                   nsStyleContext*  aContext,
                    nsIFrame*        asPrevInFlow);
 
   NS_IMETHOD GetFrameForPoint(nsIPresContext* aPresContext,
diff --git a/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp b/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp
index 6a5fbd00a87..e41aab5550c 100644
--- a/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp
+++ b/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp
@@ -57,7 +57,7 @@
 #include "nsHTMLAtoms.h"
 
 #include "nsIContent.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsIBoxObject.h"
 #include "nsGUIEvent.h"
 #include "nsIDOMMouseEvent.h"
@@ -108,15 +108,14 @@ static const PRUint32 kLazyScrollDelay = 150;
 static const PRUint32 kScrollDelay = 100;
 
 // The style context cache impl
-nsresult 
+nsStyleContext*
 nsTreeStyleCache::GetStyleContext(nsICSSPseudoComparator* aComparator,
-                                      nsIPresContext* aPresContext, nsIContent* aContent, 
-                                      nsIStyleContext* aContext, nsIAtom* aPseudoElement,
-                                      nsISupportsArray* aInputWord,
-                                      nsIStyleContext** aResult)
+                                  nsIPresContext* aPresContext,
+                                  nsIContent* aContent, 
+                                  nsStyleContext* aContext,
+                                  nsIAtom* aPseudoElement,
+                                  nsISupportsArray* aInputWord)
 {
-  *aResult = nsnull;
-  
   PRUint32 count;
   aInputWord->Count(&count);
   nsDFAState startState(0);
@@ -156,20 +155,23 @@ nsTreeStyleCache::GetStyleContext(nsICSSPseudoComparator* aComparator,
 
   // We're in a final state.
   // Look up our style context for this state.
-   if (mCache)
-    *aResult = NS_STATIC_CAST(nsIStyleContext*, mCache->Get(currState)); // Addref occurs on *aResult.
-  if (!*aResult) {
+  nsStyleContext* result;
+  if (mCache)
+    result = NS_STATIC_CAST(nsStyleContext*, mCache->Get(currState));
+  if (!result) {
     // We missed the cache. Resolve this pseudo-style.
-    aPresContext->ResolvePseudoStyleWithComparator(aContent, aPseudoElement,
-                                                   aContext, aComparator,
-                                                   aResult); // Addref occurs on *aResult.
-    // Put it in our table.
+    result = aPresContext->ResolvePseudoStyleWithComparator(aContent,
+                                                            aPseudoElement,
+                                                            aContext,
+                                                            aComparator).get();
+
+    // Put it in our table, transferring the owning reference to the table.
     if (!mCache)
-      mCache = new nsSupportsHashtable;
-    mCache->Put(currState, *aResult);
+      mCache = new nsObjectHashtable(nsnull, nsnull, ReleaseStyleContext, nsnull);
+    mCache->Put(currState, result);
   }
 
-  return NS_OK;
+  return result;
 }
 
 /* static */ PRBool PR_CALLBACK
@@ -182,6 +184,16 @@ nsTreeStyleCache::DeleteDFAState(nsHashKey *aKey,
   return PR_TRUE;
 }
 
+/* static */ PRBool PR_CALLBACK
+nsTreeStyleCache::ReleaseStyleContext(nsHashKey *aKey,
+                                      void *aData,
+                                      void *closure)
+{
+  nsStyleContext* context = NS_STATIC_CAST(nsStyleContext*, aData);
+  context->Release();
+  return PR_TRUE;
+}
+
 // Column class that caches all the info about our column.
 nsTreeColumn::nsTreeColumn(nsIContent* aColElement, nsIFrame* aFrame)
 :mNext(nsnull)
@@ -197,8 +209,7 @@ nsTreeColumn::nsTreeColumn(nsIContent* aColElement, nsIFrame* aFrame)
     mIDAtom = getter_AddRefs(NS_NewAtom(mID));
   }
 
-  nsCOMPtr<nsIStyleContext> styleContext;
-  aFrame->GetStyleContext(getter_AddRefs(styleContext));
+  nsStyleContext* styleContext = aFrame->GetStyleContext();
 
   const nsStyleVisibility* vis = 
     (const nsStyleVisibility*)styleContext->GetStyleData(eStyleStruct_Visibility);
@@ -365,7 +376,7 @@ static nsIFrame* InitScrollbarFrame(nsIPresContext* aPresContext, nsIFrame* aCur
 
 NS_IMETHODIMP
 nsTreeBodyFrame::Init(nsIPresContext* aPresContext, nsIContent* aContent,
-                          nsIFrame* aParent, nsIStyleContext* aContext, nsIFrame* aPrevInFlow)
+                          nsIFrame* aParent, nsStyleContext* aContext, nsIFrame* aPrevInFlow)
 {
   mPresContext = aPresContext;
   nsresult rv = nsLeafBoxFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
@@ -436,8 +447,7 @@ nsTreeBodyFrame::CalcMaxRowWidth(nsBoxLayoutState& aState)
   if (!mView)
     return 0;
 
-  nsCOMPtr<nsIStyleContext> rowContext;
-  GetPseudoStyleContext(nsCSSAnonBoxes::moztreerow, getter_AddRefs(rowContext));
+  nsStyleContext* rowContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreerow);
   nsMargin rowMargin(0,0,0,0);
   nsStyleBorderPadding  bPad;
   rowContext->GetBorderPaddingFor(bPad);
@@ -653,7 +663,7 @@ nsTreeBodyFrame::ReflowFinished(nsIPresShell* aPresShell, PRBool* aFlushFlag)
 
 
 static void 
-AdjustForBorderPadding(nsIStyleContext* aContext, nsRect& aRect)
+AdjustForBorderPadding(nsStyleContext* aContext, nsRect& aRect)
 {
   nsMargin m(0,0,0,0);
   nsStyleBorderPadding  bPad;
@@ -1257,16 +1267,14 @@ nsTreeBodyFrame::GetCoordsForCellItem(PRInt32 aRow, const PRUnichar *aColID, con
     PrefillPropertyArray(aRow, currCol);
     mView->GetCellProperties(aRow, currCol->GetID().get(), mScratchArray);
 
-    nsCOMPtr<nsIStyleContext> rowContext;
-    GetPseudoStyleContext(nsCSSAnonBoxes::moztreerow, getter_AddRefs(rowContext));
+    nsStyleContext* rowContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreerow);
 
     // We don't want to consider any of the decorations that may be present
     // on the current row, so we have to deflate the rect by the border and 
     // padding and offset its left and top coordinates appropriately. 
     AdjustForBorderPadding(rowContext, cellRect);
 
-    nsCOMPtr<nsIStyleContext> cellContext;
-    GetPseudoStyleContext(nsCSSAnonBoxes::moztreecell, getter_AddRefs(cellContext));
+    nsStyleContext* cellContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreecell);
 
     NS_NAMED_LITERAL_STRING(cell, "cell");
     if (currCol->IsCycler() || cell.Equals(aCellItem)) {
@@ -1314,8 +1322,7 @@ nsTreeBodyFrame::GetCoordsForCellItem(PRInt32 aRow, const PRUnichar *aColID, con
       }
 
       // Find the twisty rect by computing its size. 
-      nsCOMPtr<nsIStyleContext> twistyContext;
-      GetPseudoStyleContext(nsCSSAnonBoxes::moztreetwisty, getter_AddRefs(twistyContext));
+      nsStyleContext* twistyContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreetwisty);
 
       // |GetImageSize| returns the rect of the twisty image, including the 
       // borders and padding. 
@@ -1339,8 +1346,7 @@ nsTreeBodyFrame::GetCoordsForCellItem(PRInt32 aRow, const PRUnichar *aColID, con
     }
 
     // Cell Image
-    nsCOMPtr<nsIStyleContext> imageContext;
-    GetPseudoStyleContext(nsCSSAnonBoxes::moztreeimage, getter_AddRefs(imageContext));
+    nsStyleContext* imageContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreeimage);
 
     nsRect imageSize = GetImageSize(aRow, currCol->GetID().get(), PR_FALSE, imageContext);
     if (NS_LITERAL_STRING("image").Equals(aCellItem)) {
@@ -1367,8 +1373,7 @@ nsTreeBodyFrame::GetCoordsForCellItem(PRInt32 aRow, const PRUnichar *aColID, con
     // the remaining width available, then we just assume that the text has 
     // been cropped and use the remaining rect as the text Rect. Otherwise,
     // we add in borders and padding to the text dimension and give that back. 
-    nsCOMPtr<nsIStyleContext> textContext;
-    GetPseudoStyleContext(nsCSSAnonBoxes::moztreecelltext, getter_AddRefs(textContext));
+    nsStyleContext* textContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreecelltext);
 
     const nsStyleFont* fontStyle = (const nsStyleFont*) textContext->GetStyleData(eStyleStruct_Font);
     nsCOMPtr<nsIDeviceContext> dc;
@@ -1425,8 +1430,7 @@ nsTreeBodyFrame::GetItemWithinCellAt(PRInt32 aX, const nsRect& aCellRect,
   mView->GetCellProperties(aRowIndex, aColumn->GetID().get(), mScratchArray);
 
   // Resolve style for the cell.
-  nsCOMPtr<nsIStyleContext> cellContext;
-  GetPseudoStyleContext(nsCSSAnonBoxes::moztreecell, getter_AddRefs(cellContext));
+  nsStyleContext* cellContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreecell);
 
   // Obtain the margins for the cell and then deflate our rect by that 
   // amount.  The cell is assumed to be contained within the deflated rect.
@@ -1477,8 +1481,7 @@ nsTreeBodyFrame::GetItemWithinCellAt(PRInt32 aX, const nsRect& aCellRect,
     }
 
     // Resolve style for the twisty.
-    nsCOMPtr<nsIStyleContext> twistyContext;
-    GetPseudoStyleContext(nsCSSAnonBoxes::moztreetwisty, getter_AddRefs(twistyContext));
+    nsStyleContext* twistyContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreetwisty);
 
     // We will treat a click as hitting the twisty if it happens on the margins, borders, padding,
     // or content of the twisty object.  By allowing a "slop" into the margin, we make it a little
@@ -1509,8 +1512,7 @@ nsTreeBodyFrame::GetItemWithinCellAt(PRInt32 aX, const nsRect& aCellRect,
   nsRect iconRect(currX, cellRect.y, remainingWidth, cellRect.height);
   
   // Resolve style for the image.
-  nsCOMPtr<nsIStyleContext> imageContext;
-  GetPseudoStyleContext(nsCSSAnonBoxes::moztreeimage, getter_AddRefs(imageContext));
+  nsStyleContext* imageContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreeimage);
 
   nsRect iconSize = GetImageSize(aRowIndex, aColumn->GetID().get(), PR_FALSE, imageContext);
   const nsStyleMargin* imageMarginData = (const nsStyleMargin*)imageContext->GetStyleData(eStyleStruct_Margin);
@@ -1548,8 +1550,7 @@ nsTreeBodyFrame::GetCellWidth(PRInt32 aRow, const nsAString& aColID,
     nsRect cellRect(0, 0, currCol->GetWidth(), mRowHeight);
 
     // Adjust borders and padding for the cell.
-    nsCOMPtr<nsIStyleContext> cellContext;
-    GetPseudoStyleContext(nsCSSAnonBoxes::moztreecell, getter_AddRefs(cellContext));
+    nsStyleContext* cellContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreecell);
     nsMargin m(0,0,0,0);
     nsStyleBorderPadding  bPad;
     cellContext->GetBorderPaddingFor(bPad);
@@ -1568,8 +1569,7 @@ nsTreeBodyFrame::GetCellWidth(PRInt32 aRow, const nsAString& aColID,
       aDesiredSize += mIndentation * level;
       
       // Find the twisty rect by computing its size.
-      nsCOMPtr<nsIStyleContext> twistyContext;
-      GetPseudoStyleContext(nsCSSAnonBoxes::moztreetwisty, getter_AddRefs(twistyContext));
+      nsStyleContext* twistyContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreetwisty);
 
       // |GetImageSize| returns the rect of the twisty image, including the 
       // borders and padding.
@@ -1584,8 +1584,7 @@ nsTreeBodyFrame::GetCellWidth(PRInt32 aRow, const nsAString& aColID,
       aDesiredSize += twistyImageRect.width;
     }
 
-    nsCOMPtr<nsIStyleContext> imageContext;
-    GetPseudoStyleContext(nsCSSAnonBoxes::moztreeimage, getter_AddRefs(imageContext));
+    nsStyleContext* imageContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreeimage);
 
     // Account for the width of the cell image.
     nsRect imageSize = GetImageSize(aRow, currCol->GetID().get(), PR_FALSE, imageContext);
@@ -1595,8 +1594,7 @@ nsTreeBodyFrame::GetCellWidth(PRInt32 aRow, const nsAString& aColID,
     nsAutoString cellText;
     mView->GetCellText(aRow, currCol->GetID().get(), cellText);
 
-    nsCOMPtr<nsIStyleContext> textContext;
-    GetPseudoStyleContext(nsCSSAnonBoxes::moztreecelltext, getter_AddRefs(textContext));
+    nsStyleContext* textContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreecelltext);
 
     // Get the borders and padding for the text.
     nsStyleBorderPadding borderPadding;
@@ -1800,7 +1798,7 @@ nsTreeBodyFrame::PrefillPropertyArray(PRInt32 aRowIndex, nsTreeColumn* aCol)
 
 nsresult
 nsTreeBodyFrame::GetImage(PRInt32 aRowIndex, const PRUnichar* aColID, PRBool aUseContext,
-                          nsIStyleContext* aStyleContext, PRBool& aAllowImageRegions, imgIContainer** aResult)
+                          nsStyleContext* aStyleContext, PRBool& aAllowImageRegions, imgIContainer** aResult)
 {
   *aResult = nsnull;
 
@@ -1901,7 +1899,7 @@ nsTreeBodyFrame::GetImage(PRInt32 aRowIndex, const PRUnichar* aColID, PRBool aUs
 }
 
 nsRect nsTreeBodyFrame::GetImageSize(PRInt32 aRowIndex, const PRUnichar* aColID, PRBool aUseContext,
-                                         nsIStyleContext* aStyleContext)
+                                     nsStyleContext* aStyleContext)
 {
   // XXX We should respond to visibility rules for collapsed vs. hidden.
 
@@ -1983,9 +1981,8 @@ PRInt32 nsTreeBodyFrame::GetRowHeight()
 {
   // Look up the correct height.  It is equal to the specified height
   // + the specified margins.
-  nsCOMPtr<nsIStyleContext> rowContext;
   mScratchArray->Clear();
-  GetPseudoStyleContext(nsCSSAnonBoxes::moztreerow, getter_AddRefs(rowContext));
+  nsStyleContext* rowContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreerow);
   if (rowContext) {
     const nsStylePosition* myPosition = (const nsStylePosition*)
           rowContext->GetStyleData(eStyleStruct_Position);
@@ -2030,9 +2027,8 @@ PRInt32 nsTreeBodyFrame::GetRowHeight()
 PRInt32 nsTreeBodyFrame::GetIndentation()
 {
   // Look up the correct indentation.  It is equal to the specified indentation width.
-  nsCOMPtr<nsIStyleContext> indentContext;
   mScratchArray->Clear();
-  GetPseudoStyleContext(nsCSSAnonBoxes::moztreeindentation, getter_AddRefs(indentContext));
+  nsStyleContext* indentContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreeindentation);
   if (indentContext) {
     const nsStylePosition* myPosition = (const nsStylePosition*)
           indentContext->GetStyleData(eStyleStruct_Position);
@@ -2194,8 +2190,7 @@ nsTreeBodyFrame::PaintColumn(nsTreeColumn*        aColumn,
   
   // Resolve style for the column.  It contains all the info we need to lay ourselves
   // out and to paint.
-  nsCOMPtr<nsIStyleContext> colContext;
-  GetPseudoStyleContext(nsCSSAnonBoxes::moztreecolumn, getter_AddRefs(colContext));
+  nsStyleContext* colContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreecolumn);
 
   // Obtain the margins for the cell and then deflate our rect by that 
   // amount.  The cell is assumed to be contained within the deflated rect.
@@ -2232,8 +2227,7 @@ nsTreeBodyFrame::PaintRow(PRInt32              aRowIndex,
 
   // Resolve style for the row.  It contains all the info we need to lay ourselves
   // out and to paint.
-  nsCOMPtr<nsIStyleContext> rowContext;
-  GetPseudoStyleContext(nsCSSAnonBoxes::moztreerow, getter_AddRefs(rowContext));
+  nsStyleContext* rowContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreerow);
 
   // Obtain the margins for the row and then deflate our rect by that 
   // amount.  The row is assumed to be contained within the deflated rect.
@@ -2276,8 +2270,7 @@ nsTreeBodyFrame::PaintRow(PRInt32              aRowIndex,
     // The row is a separator. Paint only a double horizontal line.
 
     // Resolve style for the separator.
-    nsCOMPtr<nsIStyleContext> separatorContext;
-    GetPseudoStyleContext(nsCSSAnonBoxes::moztreeseparator, getter_AddRefs(separatorContext));
+    nsStyleContext* separatorContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreeseparator);
     PRBool useTheme = PR_FALSE;
     nsCOMPtr<nsITheme> theme;
     const nsStyleDisplay* displayData = (const nsStyleDisplay*)separatorContext->GetStyleData(eStyleStruct_Display);
@@ -2356,8 +2349,7 @@ nsTreeBodyFrame::PaintCell(PRInt32              aRowIndex,
 
   // Resolve style for the cell.  It contains all the info we need to lay ourselves
   // out and to paint.
-  nsCOMPtr<nsIStyleContext> cellContext;
-  GetPseudoStyleContext(nsCSSAnonBoxes::moztreecell, getter_AddRefs(cellContext));
+  nsStyleContext* cellContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreecell);
 
   // Obtain the margins for the cell and then deflate our rect by that 
   // amount.  The cell is assumed to be contained within the deflated rect.
@@ -2395,8 +2387,7 @@ nsTreeBodyFrame::PaintCell(PRInt32              aRowIndex,
     remainingWidth -= mIndentation * level;
 
     // Resolve the style to use for the connecting lines.
-    nsCOMPtr<nsIStyleContext> lineContext;
-    GetPseudoStyleContext(nsCSSAnonBoxes::moztreeline, getter_AddRefs(lineContext));
+    nsStyleContext* lineContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreeline);
     const nsStyleVisibility* vis = 
       (const nsStyleVisibility*)lineContext->GetStyleData(eStyleStruct_Visibility);
     
@@ -2406,8 +2397,7 @@ nsTreeBodyFrame::PaintCell(PRInt32              aRowIndex,
       // Get the size of the twisty. We don't want to paint the twisty
       // before painting of connecting lines since it would paint lines over
       // the twisty. But we need to leave a place for it.
-      nsCOMPtr<nsIStyleContext> twistyContext;
-      GetPseudoStyleContext(nsCSSAnonBoxes::moztreetwisty, getter_AddRefs(twistyContext));
+      nsStyleContext* twistyContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreetwisty);
 
       nsRect twistySize = GetImageSize(aRowIndex, aColumn->GetID().get(), PR_TRUE, twistyContext);
 
@@ -2546,8 +2536,7 @@ nsTreeBodyFrame::PaintTwisty(PRInt32              aRowIndex,
   }
 
   // Resolve style for the twisty.
-  nsCOMPtr<nsIStyleContext> twistyContext;
-  GetPseudoStyleContext(nsCSSAnonBoxes::moztreetwisty, getter_AddRefs(twistyContext));
+  nsStyleContext* twistyContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreetwisty);
 
   PRBool useTheme = PR_FALSE;
   nsCOMPtr<nsITheme> theme;
@@ -2654,8 +2643,7 @@ nsTreeBodyFrame::PaintImage(PRInt32              aRowIndex,
                             nscoord&             aCurrX)
 {
   // Resolve style for the image.
-  nsCOMPtr<nsIStyleContext> imageContext;
-  GetPseudoStyleContext(nsCSSAnonBoxes::moztreeimage, getter_AddRefs(imageContext));
+  nsStyleContext* imageContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreeimage);
 
   // Obtain the margins for the twisty and then deflate our rect by that 
   // amount.  The twisty is assumed to be contained within the deflated rect.
@@ -2743,8 +2731,7 @@ nsTreeBodyFrame::PaintText(PRInt32              aRowIndex,
 
   // Resolve style for the text.  It contains all the info we need to lay ourselves
   // out and to paint.
-  nsCOMPtr<nsIStyleContext> textContext;
-  GetPseudoStyleContext(nsCSSAnonBoxes::moztreecelltext, getter_AddRefs(textContext));
+  nsStyleContext* textContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreecelltext);
 
   // Obtain the margins for the text and then deflate our rect by that 
   // amount.  The text is assumed to be contained within the deflated rect.
@@ -2967,8 +2954,7 @@ nsTreeBodyFrame::PaintProgressMeter(PRInt32              aRowIndex,
 
   // Resolve style for the progress meter.  It contains all the info we need
   // to lay ourselves out and to paint.
-  nsCOMPtr<nsIStyleContext> meterContext;
-  GetPseudoStyleContext(nsCSSAnonBoxes::moztreeprogressmeter, getter_AddRefs(meterContext));
+  nsStyleContext* meterContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreeprogressmeter);
 
   // Obtain the margins for the progress meter and then deflate our rect by that 
   // amount. The progress meter is assumed to be contained within the deflated
@@ -3061,8 +3047,7 @@ nsTreeBodyFrame::PaintDropFeedback(nsIPresContext*      aPresContext,
         PrefillPropertyArray(mDropRow, currCol);
 
         // Resolve the style to use for the drop feedback.
-        nsCOMPtr<nsIStyleContext> feedbackContext;
-        GetPseudoStyleContext(nsCSSAnonBoxes::moztreedropfeedback, getter_AddRefs(feedbackContext));
+        nsStyleContext* feedbackContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreedropfeedback);
 
         const nsStyleVisibility* vis = 
           (const nsStyleVisibility*)feedbackContext->GetStyleData(eStyleStruct_Visibility);
@@ -3095,8 +3080,7 @@ nsTreeBodyFrame::PaintDropFeedback(nsIPresContext*      aPresContext,
 
           currX += mIndentation * level;
 
-          nsCOMPtr<nsIStyleContext> twistyContext;
-          GetPseudoStyleContext(nsCSSAnonBoxes::moztreetwisty, getter_AddRefs(twistyContext));
+          nsStyleContext* twistyContext = GetPseudoStyleContext(nsCSSAnonBoxes::moztreetwisty);
           nsRect twistySize = GetImageSize(mDropRow, currCol->GetID().get(), PR_TRUE, twistyContext);
           const nsStyleMargin* twistyMarginData = (const nsStyleMargin*)twistyContext->GetStyleData(eStyleStruct_Margin);
           nsMargin twistyMargin;
@@ -3149,7 +3133,7 @@ nsTreeBodyFrame::PaintDropFeedback(nsIPresContext*      aPresContext,
 }
 
 nsresult
-nsTreeBodyFrame::PaintBackgroundLayer(nsIStyleContext*     aStyleContext,
+nsTreeBodyFrame::PaintBackgroundLayer(nsStyleContext*      aStyleContext,
                                       nsIPresContext*      aPresContext, 
                                       nsIRenderingContext& aRenderingContext, 
                                       const nsRect&        aRect,
@@ -3338,12 +3322,12 @@ nsTreeBodyFrame::PositionChanged(PRInt32 aOldIndex, PRInt32& aNewIndex)
 }
 
 // The style cache.
-nsresult 
-nsTreeBodyFrame::GetPseudoStyleContext(nsIAtom* aPseudoElement, 
-                                           nsIStyleContext** aResult)
+nsStyleContext*
+nsTreeBodyFrame::GetPseudoStyleContext(nsIAtom* aPseudoElement)
 {
-  return mStyleCache.GetStyleContext(this, mPresContext, mContent, mStyleContext, aPseudoElement,
-                                     mScratchArray, aResult);
+  return mStyleCache.GetStyleContext(this, mPresContext, mContent,
+                                     mStyleContext, aPseudoElement,
+                                     mScratchArray);
 }
 
 // Our comparator for resolving our complex pseudos
diff --git a/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.h b/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.h
index a1de7de0790..c679e70a2b0 100644
--- a/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.h
+++ b/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.h
@@ -112,14 +112,17 @@ public:
 
   void Clear() { delete mTransitionTable; mTransitionTable = nsnull; delete mCache; mCache = nsnull; mNextState = 0; };
 
-  nsresult GetStyleContext(nsICSSPseudoComparator* aComparator, nsIPresContext* aPresContext, 
-                           nsIContent* aContent, 
-                           nsIStyleContext* aContext, nsIAtom* aPseudoElement,
-                           nsISupportsArray* aInputWord,
-                           nsIStyleContext** aResult);
+  nsStyleContext* GetStyleContext(nsICSSPseudoComparator* aComparator,
+                                  nsIPresContext* aPresContext, 
+                                  nsIContent* aContent, 
+                                  nsStyleContext* aContext,
+                                  nsIAtom* aPseudoElement,
+                                  nsISupportsArray* aInputWord);
 
   static PRBool PR_CALLBACK DeleteDFAState(nsHashKey *aKey, void *aData, void *closure);
 
+  static PRBool PR_CALLBACK ReleaseStyleContext(nsHashKey *aKey, void *aData, void *closure);
+
 protected:
   // A transition table for a deterministic finite automaton.  The DFA
   // takes as its input a single pseudoelement and an ordered set of properties.  
@@ -139,7 +142,7 @@ protected:
 
   // The cache of all active style contexts.  This is a hash from 
   // a final state in the DFA, Sf, to the resultant style context.
-  nsSupportsHashtable* mCache;
+  nsObjectHashtable* mCache;
 
   // An integer counter that is used when we need to make new states in the
   // DFA.
@@ -259,7 +262,7 @@ public:
 
   // Overridden from nsIFrame to cache our pres context.
   NS_IMETHOD Init(nsIPresContext* aPresContext, nsIContent* aContent,
-                  nsIFrame* aParent, nsIStyleContext* aContext, nsIFrame* aPrevInFlow);
+                  nsIFrame* aParent, nsStyleContext* aContext, nsIFrame* aPrevInFlow);
   NS_IMETHOD Destroy(nsIPresContext* aPresContext);
 
   // Painting methods.
@@ -353,7 +356,7 @@ public:
 
   // This method is called with a specific style context and rect to
   // paint the background rect as if it were a full-blown frame.
-  nsresult PaintBackgroundLayer(nsIStyleContext*     aStyleContext,
+  nsresult PaintBackgroundLayer(nsStyleContext*      aStyleContext,
                                 nsIPresContext*      aPresContext, 
                                 nsIRenderingContext& aRenderingContext, 
                                 const nsRect&        aRect,
@@ -381,11 +384,11 @@ protected:
 
   // Fetch an image from the image cache.
   nsresult GetImage(PRInt32 aRowIndex, const PRUnichar* aColID, PRBool aUseContext,
-                    nsIStyleContext* aStyleContext, PRBool& aAllowImageRegions, imgIContainer** aResult);
+                    nsStyleContext* aStyleContext, PRBool& aAllowImageRegions, imgIContainer** aResult);
 
   // Returns the size of a given image.   This size *includes* border and
   // padding.  It does not include margins.
-  nsRect GetImageSize(PRInt32 aRowIndex, const PRUnichar* aColID, PRBool aUseContext, nsIStyleContext* aStyleContext);
+  nsRect GetImageSize(PRInt32 aRowIndex, const PRUnichar* aColID, PRBool aUseContext, nsStyleContext* aStyleContext);
 
   // Returns the height of rows in the tree.
   PRInt32 GetRowHeight();
@@ -398,7 +401,7 @@ protected:
 
   // Looks up a style context in the style cache.  On a cache miss we resolve
   // the pseudo-styles passed in and place them into the cache.
-  nsresult GetPseudoStyleContext(nsIAtom* aPseudoElement, nsIStyleContext** aResult);
+  nsStyleContext* GetPseudoStyleContext(nsIAtom* aPseudoElement);
 
   // Builds our cache of column info.
   void EnsureColumns();
diff --git a/mozilla/layout/xul/base/src/tree/src/nsTreeColFrame.cpp b/mozilla/layout/xul/base/src/tree/src/nsTreeColFrame.cpp
index d52be3ef4f2..4d374870b0a 100644
--- a/mozilla/layout/xul/base/src/tree/src/nsTreeColFrame.cpp
+++ b/mozilla/layout/xul/base/src/tree/src/nsTreeColFrame.cpp
@@ -41,7 +41,7 @@
 #include "nsXULAtoms.h"
 #include "nsHTMLAtoms.h"
 #include "nsIContent.h"
-#include "nsIStyleContext.h"
+#include "nsStyleContext.h"
 #include "nsINameSpaceManager.h" 
 #include "nsIDOMNSDocument.h"
 #include "nsIDocument.h"
@@ -102,7 +102,7 @@ NS_IMETHODIMP
 nsTreeColFrame::Init(nsIPresContext*  aPresContext,
                          nsIContent*      aContent,
                          nsIFrame*        aParent,
-                         nsIStyleContext* aContext,
+                         nsStyleContext*  aContext,
                          nsIFrame*        aPrevInFlow)
 {
   nsresult rv = nsBoxFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
diff --git a/mozilla/layout/xul/base/src/tree/src/nsTreeColFrame.h b/mozilla/layout/xul/base/src/tree/src/nsTreeColFrame.h
index 71ff53cdc36..dc78a6e2d02 100644
--- a/mozilla/layout/xul/base/src/tree/src/nsTreeColFrame.h
+++ b/mozilla/layout/xul/base/src/tree/src/nsTreeColFrame.h
@@ -60,7 +60,7 @@ public:
   NS_IMETHODIMP Init(nsIPresContext*  aPresContext,
                      nsIContent*      aContent,
                      nsIFrame*        aParent,
-                     nsIStyleContext* aContext,
+                     nsStyleContext*  aContext,
                      nsIFrame*        aPrevInFlow);
 
   NS_IMETHOD GetFrameForPoint(nsIPresContext* aPresContext,
diff --git a/mozilla/xpcom/base/MANIFEST b/mozilla/xpcom/base/MANIFEST
index bae3468b9ab..db27fa7aec4 100644
--- a/mozilla/xpcom/base/MANIFEST
+++ b/mozilla/xpcom/base/MANIFEST
@@ -1,4 +1,5 @@
 nsAgg.h
+nsAutoPtr.h
 nsIAllocator.h
 nsCom.h
 nsComObsolete.h
diff --git a/mozilla/xpcom/base/Makefile.in b/mozilla/xpcom/base/Makefile.in
index f3b0f0e91b4..ff98ae816ef 100644
--- a/mozilla/xpcom/base/Makefile.in
+++ b/mozilla/xpcom/base/Makefile.in
@@ -54,6 +54,7 @@ endif
 
 EXPORTS		= \
 		nsAgg.h \
+		nsAutoPtr.h \
 		nsIAllocator.h \
 		nsCom.h \
 		nsComObsolete.h \
diff --git a/mozilla/xpcom/glue/nsCOMPtr.h b/mozilla/xpcom/glue/nsCOMPtr.h
index 769636d8cf0..f1348d5f414 100644
--- a/mozilla/xpcom/glue/nsCOMPtr.h
+++ b/mozilla/xpcom/glue/nsCOMPtr.h
@@ -188,8 +188,8 @@ class nsDerivedSafe : public T
       using T::AddRef;
       using T::Release;
 #else
-      NS_IMETHOD_(nsrefcnt) AddRef(void);
-      NS_IMETHOD_(nsrefcnt) Release(void);
+      nsrefcnt AddRef(void);
+      nsrefcnt Release(void);
 #endif
 
 #if !defined(XP_OS2_VACPP) && !defined(AIX_XLC_364)
diff --git a/mozilla/xpcom/tests/Makefile.in b/mozilla/xpcom/tests/Makefile.in
index eca98de2ef9..5471742b946 100644
--- a/mozilla/xpcom/tests/Makefile.in
+++ b/mozilla/xpcom/tests/Makefile.in
@@ -55,6 +55,7 @@ CPPSRCS		= \
 		TestThreads.cpp \
 		TestXPIDLString.cpp \
 		TestDeque.cpp \
+		TestAutoPtr.cpp \
 		$(NULL)
 
 #CPPSRCS		+= TimerTest.cpp