diff --git a/mozilla/content/base/src/nsDocumentViewer.cpp b/mozilla/content/base/src/nsDocumentViewer.cpp
index 06c9ec4b1ea..887f89e66e5 100644
--- a/mozilla/content/base/src/nsDocumentViewer.cpp
+++ b/mozilla/content/base/src/nsDocumentViewer.cpp
@@ -120,7 +120,7 @@
 #include "nsIFocusController.h"
 
 #include "nsIScrollableView.h"
-#include "nsIScrollable.h"
+#include "nsIHTMLDocument.h"
 #include "nsITimelineService.h"
 #include "nsGfxCIID.h"
 
@@ -678,23 +678,11 @@ DocumentViewerImpl::InitPresentationStuff(PRBool aDoInitialReflow)
   mViewManager->SetDefaultBackgroundColor(mPresContext->DefaultBackgroundColor());
 
   if (aDoInitialReflow) {
-    nsCOMPtr<nsIScrollable> sc = do_QueryInterface(mContainer);
-
-    if (sc) {
-      nsCOMPtr<nsIDOMHTMLFrameSetElement> frameset(do_QueryInterface(mDocument->GetRootContent()));
-
-      if (frameset) {
-        // If this is a frameset (i.e. not a frame) then we never want
-        // scrollbars on it, the scrollbars go inside the frames
-        // inside the frameset...
-
-        sc->SetCurrentScrollbarPreferences(nsIScrollable::ScrollOrientation_Y,
-                                           NS_STYLE_OVERFLOW_HIDDEN);
-        sc->SetCurrentScrollbarPreferences(nsIScrollable::ScrollOrientation_X,
-                                           NS_STYLE_OVERFLOW_HIDDEN);
-      } else {
-        sc->ResetScrollbarPreferences();
-      }
+    nsCOMPtr<nsIHTMLDocument> htmlDoc = do_QueryInterface(mDocument);
+    if (htmlDoc) {
+      nsCOMPtr<nsIDOMHTMLFrameSetElement> frameset =
+        do_QueryInterface(mDocument->GetRootContent());
+      htmlDoc->SetIsFrameset(frameset != nsnull);
     }
 
     // Initial reflow
diff --git a/mozilla/content/base/src/nsRuleNode.cpp b/mozilla/content/base/src/nsRuleNode.cpp
index 70b8ddb1114..2c0a7cafc20 100644
--- a/mozilla/content/base/src/nsRuleNode.cpp
+++ b/mozilla/content/base/src/nsRuleNode.cpp
@@ -2614,16 +2614,55 @@ nsRuleNode::ComputeDisplayData(nsStyleStruct* aStartStruct,
     display->mFloats = parentDisplay->mFloats;
   }
 
-  // overflow: enum, auto, inherit
-  if (eCSSUnit_Enumerated == displayData.mOverflow.GetUnit()) {
-    display->mOverflow = displayData.mOverflow.GetIntValue();
+  // overflow-x: enum, auto, inherit
+  if (eCSSUnit_Enumerated == displayData.mOverflowX.GetUnit()) {
+    display->mOverflowX = displayData.mOverflowX.GetIntValue();
   }
-  else if (eCSSUnit_Auto == displayData.mOverflow.GetUnit()) {
-    display->mOverflow = NS_STYLE_OVERFLOW_AUTO;
+  else if (eCSSUnit_Auto == displayData.mOverflowX.GetUnit()) {
+    display->mOverflowX = NS_STYLE_OVERFLOW_AUTO;
   }
-  else if (eCSSUnit_Inherit == displayData.mOverflow.GetUnit()) {
+  else if (eCSSUnit_Inherit == displayData.mOverflowX.GetUnit()) {
     inherited = PR_TRUE;
-    display->mOverflow = parentDisplay->mOverflow;
+    display->mOverflowX = parentDisplay->mOverflowX;
+  }
+
+  // overflow-y: enum, auto, inherit
+  if (eCSSUnit_Enumerated == displayData.mOverflowY.GetUnit()) {
+    display->mOverflowY = displayData.mOverflowY.GetIntValue();
+  }
+  else if (eCSSUnit_Auto == displayData.mOverflowY.GetUnit()) {
+    display->mOverflowY = NS_STYLE_OVERFLOW_AUTO;
+  }
+  else if (eCSSUnit_Inherit == displayData.mOverflowY.GetUnit()) {
+    inherited = PR_TRUE;
+    display->mOverflowY = parentDisplay->mOverflowY;
+  }
+
+  // CSS3 overflow-x and overflow-y require some fixup as well in some
+  // cases.  NS_STYLE_OVERFLOW_VISIBLE and NS_STYLE_OVERFLOW_CLIP are
+  // meaningful only when used in both dimensions.
+  if (display->mOverflowX != display->mOverflowY &&
+      (display->mOverflowX == NS_STYLE_OVERFLOW_VISIBLE ||
+       display->mOverflowX == NS_STYLE_OVERFLOW_CLIP ||
+       display->mOverflowY == NS_STYLE_OVERFLOW_VISIBLE ||
+       display->mOverflowY == NS_STYLE_OVERFLOW_CLIP)) {
+    // We can't store in the rule tree since a more specific rule might
+    // change these conditions.
+    inherited = PR_TRUE;
+
+    // NS_STYLE_OVERFLOW_CLIP is a deprecated value, so if it's specified
+    // in only one dimension, convert it to NS_STYLE_OVERFLOW_HIDDEN.
+    if (display->mOverflowX == NS_STYLE_OVERFLOW_CLIP)
+      display->mOverflowX = NS_STYLE_OVERFLOW_HIDDEN;
+    if (display->mOverflowY == NS_STYLE_OVERFLOW_CLIP)
+      display->mOverflowY = NS_STYLE_OVERFLOW_HIDDEN;
+
+    // If 'visible' is specified but doesn't match the other dimension, it
+    // turns into 'auto'.
+    if (display->mOverflowX == NS_STYLE_OVERFLOW_VISIBLE)
+      display->mOverflowX = NS_STYLE_OVERFLOW_AUTO;
+    if (display->mOverflowY == NS_STYLE_OVERFLOW_VISIBLE)
+      display->mOverflowY = NS_STYLE_OVERFLOW_AUTO;
   }
 
   // clip property: length, auto, inherit
diff --git a/mozilla/content/html/content/src/nsGenericHTMLElement.cpp b/mozilla/content/html/content/src/nsGenericHTMLElement.cpp
index 79437d43c21..25493ac282f 100644
--- a/mozilla/content/html/content/src/nsGenericHTMLElement.cpp
+++ b/mozilla/content/html/content/src/nsGenericHTMLElement.cpp
@@ -3028,34 +3028,39 @@ nsGenericHTMLElement::MapScrollingAttributeInto(const nsMappedAttributes* aAttri
     return;
 
   // scrolling
-  if (aData->mDisplayData->mOverflow.GetUnit() == eCSSUnit_Null) {
-    const nsAttrValue* value = aAttributes->GetAttr(nsHTMLAtoms::scrolling);
-    if (value && value->Type() == nsAttrValue::eEnum) {
-      PRInt32 mappedValue;
-      switch (value->GetEnumValue()) {
-        case NS_STYLE_FRAME_ON:
-        case NS_STYLE_FRAME_SCROLL:
-        case NS_STYLE_FRAME_YES:
-          mappedValue = NS_STYLE_OVERFLOW_SCROLL;
-          break;
+  nsCSSValue* overflowValues[2] = {
+    &aData->mDisplayData->mOverflowX,
+    &aData->mDisplayData->mOverflowY,
+  };
+  for (PRInt32 i = 0; i < NS_ARRAY_LENGTH(overflowValues); ++i) {
+    if (overflowValues[i]->GetUnit() == eCSSUnit_Null) {
+      const nsAttrValue* value = aAttributes->GetAttr(nsHTMLAtoms::scrolling);
+      if (value && value->Type() == nsAttrValue::eEnum) {
+        PRInt32 mappedValue;
+        switch (value->GetEnumValue()) {
+          case NS_STYLE_FRAME_ON:
+          case NS_STYLE_FRAME_SCROLL:
+          case NS_STYLE_FRAME_YES:
+            mappedValue = NS_STYLE_OVERFLOW_SCROLL;
+            break;
 
-        case NS_STYLE_FRAME_OFF:
-        case NS_STYLE_FRAME_NOSCROLL:
-        case NS_STYLE_FRAME_NO:
-          mappedValue = NS_STYLE_OVERFLOW_HIDDEN;
-          break;
-      
-        case NS_STYLE_FRAME_AUTO:
-          mappedValue = NS_STYLE_OVERFLOW_AUTO;
-          break;
+          case NS_STYLE_FRAME_OFF:
+          case NS_STYLE_FRAME_NOSCROLL:
+          case NS_STYLE_FRAME_NO:
+            mappedValue = NS_STYLE_OVERFLOW_HIDDEN;
+            break;
+        
+          case NS_STYLE_FRAME_AUTO:
+            mappedValue = NS_STYLE_OVERFLOW_AUTO;
+            break;
 
-        default:
-          NS_NOTREACHED("unexpected value");
-          mappedValue = NS_STYLE_OVERFLOW_AUTO;
-          break;
+          default:
+            NS_NOTREACHED("unexpected value");
+            mappedValue = NS_STYLE_OVERFLOW_AUTO;
+            break;
+        }
+        overflowValues[i]->SetIntValue(mappedValue, eCSSUnit_Enumerated);
       }
-      aData->mDisplayData->mOverflow.SetIntValue(mappedValue,
-                                                 eCSSUnit_Enumerated);
     }
   }
 }
diff --git a/mozilla/content/html/document/src/nsHTMLContentSink.cpp b/mozilla/content/html/document/src/nsHTMLContentSink.cpp
index 0b99103f65b..f2f2fefb770 100644
--- a/mozilla/content/html/document/src/nsHTMLContentSink.cpp
+++ b/mozilla/content/html/document/src/nsHTMLContentSink.cpp
@@ -108,7 +108,6 @@
 #include "nsTimer.h"
 #include "nsITimer.h"
 #include "nsDOMError.h"
-#include "nsIScrollable.h"
 #include "nsContentPolicyUtils.h"
 #include "nsIScriptContext.h"
 #include "nsStyleLinkElement.h"
@@ -3646,24 +3645,9 @@ HTMLContentSink::StartLayout()
 
   mLastNotificationTime = PR_Now();
 
-  // If it's a frameset document then disable scrolling.
-  // Else, reset scrolling to default settings for this shell.
-  // This must happen before the initial reflow, when we create the root frame
-  nsCOMPtr<nsIScrollable> scrollableContainer = do_QueryInterface(mDocShell);
-  if (scrollableContainer) {
-    if (mFrameset) {
-      scrollableContainer->
-        SetCurrentScrollbarPreferences(nsIScrollable::ScrollOrientation_Y,
-                                       NS_STYLE_OVERFLOW_HIDDEN);
-      scrollableContainer->
-        SetCurrentScrollbarPreferences(nsIScrollable::ScrollOrientation_X,
-                                       NS_STYLE_OVERFLOW_HIDDEN);
-    } else {
-      scrollableContainer->ResetScrollbarPreferences();
-    }
-  }
+  mHTMLDocument->SetIsFrameset(mFrameset != nsnull);
 
-  nsContentSink::StartLayout(!!mFrameset);
+  nsContentSink::StartLayout(mFrameset != nsnull);
 }
 
 void
diff --git a/mozilla/content/html/document/src/nsHTMLDocument.h b/mozilla/content/html/document/src/nsHTMLDocument.h
index 3ff0e760270..3b0037b6e86 100644
--- a/mozilla/content/html/document/src/nsHTMLDocument.h
+++ b/mozilla/content/html/document/src/nsHTMLDocument.h
@@ -119,6 +119,9 @@ public:
     return mWriteLevel != PRUint32(0);
   }
 
+  virtual PRBool GetIsFrameset() { return mIsFrameset; }
+  virtual void SetIsFrameset(PRBool aFrameset) { mIsFrameset = aFrameset; }
+
   virtual void ContentAppended(nsIContent* aContainer,
                                PRInt32 aNewIndexInContainer);
   virtual void ContentInserted(nsIContent* aContainer,
@@ -319,6 +322,8 @@ protected:
    */
   PRPackedBool mDomainWasSet;
 
+  PRPackedBool mIsFrameset;
+
   PLDHashTable mIdAndNameHashTable;
 
   nsCOMPtr<nsIWyciwygChannel> mWyciwygChannel;
diff --git a/mozilla/content/html/document/src/nsIHTMLDocument.h b/mozilla/content/html/document/src/nsIHTMLDocument.h
index ab9848cfbc8..12eae9914b5 100644
--- a/mozilla/content/html/document/src/nsIHTMLDocument.h
+++ b/mozilla/content/html/document/src/nsIHTMLDocument.h
@@ -111,6 +111,9 @@ public:
   virtual PRInt32 GetNumFormsSynchronous() = 0;
   
   virtual PRBool IsWriting() = 0;
+
+  virtual PRBool GetIsFrameset() = 0;
+  virtual void SetIsFrameset(PRBool aFrameset) = 0;
 };
 
 #endif /* nsIHTMLDocument_h___ */
diff --git a/mozilla/content/html/document/src/nsMediaDocument.cpp b/mozilla/content/html/document/src/nsMediaDocument.cpp
index c23378527df..2fe13f86d56 100644
--- a/mozilla/content/html/document/src/nsMediaDocument.cpp
+++ b/mozilla/content/html/document/src/nsMediaDocument.cpp
@@ -267,13 +267,6 @@ nsMediaDocument::CreateSyntheticDocument()
 nsresult
 nsMediaDocument::StartLayout()
 {
-  // Reset scrolling to default settings for this shell.
-  // This must happen before the initial reflow, when we create the root frame
-  nsCOMPtr<nsIScrollable> scrollableContainer(do_QueryReferent(mDocumentContainer));
-  if (scrollableContainer) {
-    scrollableContainer->ResetScrollbarPreferences();
-  }
-
   PRUint32 numberOfShells = GetNumberOfShells();
   for (PRUint32 i = 0; i < numberOfShells; i++) {
     nsIPresShell *shell = GetShellAt(i);
diff --git a/mozilla/content/html/style/src/nsCSSDeclaration.cpp b/mozilla/content/html/style/src/nsCSSDeclaration.cpp
index 66ad6686027..84df769f526 100644
--- a/mozilla/content/html/style/src/nsCSSDeclaration.cpp
+++ b/mozilla/content/html/style/src/nsCSSDeclaration.cpp
@@ -500,6 +500,7 @@ nsCSSDeclaration::GetValue(nsCSSProperty aProperty,
 
   // shorthands
   // XXX What about checking the consistency of '!important'?
+  // XXXldb Can we share shorthand logic with ToString?
   switch (aProperty) {
     case eCSSProperty_margin: 
     case eCSSProperty_padding: 
@@ -629,6 +630,14 @@ nsCSSDeclaration::GetValue(nsCSSProperty aProperty,
         aValue.Append(PRUnichar(' '));
       AppendValueToString(eCSSProperty_list_style_image, aValue);
       break;
+    case eCSSProperty_overflow: {
+      nsCSSValue xValue, yValue;
+      GetValueOrImportantValue(eCSSProperty_overflow_x, xValue);
+      GetValueOrImportantValue(eCSSProperty_overflow_y, yValue);
+      if (xValue == yValue)
+        AppendValueToString(eCSSProperty_overflow_x, aValue);
+      break;
+    }
     case eCSSProperty_pause: {
       if (AppendValueToString(eCSSProperty_pause_after, aValue)) {
         aValue.Append(PRUnichar(' '));
@@ -968,6 +977,27 @@ nsCSSDeclaration::UseBackgroundPosition(nsAString & aString,
   aBgPositionY = 0;
 }
 
+void
+nsCSSDeclaration::TryOverflowShorthand(nsAString & aString,
+                                       PRInt32 & aOverflowX,
+                                       PRInt32 & aOverflowY) const
+{
+  PRBool isImportant;
+  if (aOverflowX && aOverflowY &&
+      AllPropertiesSameImportance(aOverflowX, aOverflowY,
+                                  0, 0, 0, 0, isImportant)) {
+    nsCSSValue xValue, yValue;
+    GetValueOrImportantValue(eCSSProperty_overflow_x, xValue);
+    GetValueOrImportantValue(eCSSProperty_overflow_y, yValue);
+    if (xValue == yValue) {
+      AppendCSSValueToString(eCSSProperty_overflow_x, xValue, aString);
+      AppendImportanceToString(isImportant, aString);
+      aString.AppendLiteral("; ");
+      aOverflowX = aOverflowY = 0;
+    }
+  }
+}
+
 #define NS_CASE_OUTPUT_PROPERTY_VALUE(_prop, _index) \
 case _prop: \
           if (_index) { \
@@ -1012,6 +1042,7 @@ nsCSSDeclaration::ToString(nsAString& aString) const
   PRInt32 paddingTop = 0, paddingBottom = 0, paddingLeft = 0, paddingRight = 0;
   PRInt32 bgColor = 0, bgImage = 0, bgRepeat = 0, bgAttachment = 0;
   PRInt32 bgPositionX = 0, bgPositionY = 0;
+  PRInt32 overflowX = 0, overflowY = 0;
   PRUint32 borderPropertiesSet = 0, finalBorderPropertiesToSet = 0;
   for (index = 0; index < count; index++) {
     nsCSSProperty property = OrderValueAt(index);
@@ -1055,23 +1086,27 @@ nsCSSDeclaration::ToString(nsAString& aString) const
         PropertyIsSet(borderRightColor, index, borderPropertiesSet, B_BORDER_RIGHT_COLOR);
         break;
 
-      case eCSSProperty_margin_top:            marginTop         = index+1; break;
-      case eCSSProperty_margin_bottom:         marginBottom      = index+1; break;
-      case eCSSProperty_margin_left_value:     marginLeft        = index+1; break;
-      case eCSSProperty_margin_right_value:    marginRight       = index+1; break;
+      case eCSSProperty_margin_top:            marginTop     = index+1; break;
+      case eCSSProperty_margin_bottom:         marginBottom  = index+1; break;
+      case eCSSProperty_margin_left_value:     marginLeft    = index+1; break;
+      case eCSSProperty_margin_right_value:    marginRight   = index+1; break;
 
-      case eCSSProperty_padding_top:           paddingTop        = index+1; break;
-      case eCSSProperty_padding_bottom:        paddingBottom     = index+1; break;
-      case eCSSProperty_padding_left_value:    paddingLeft       = index+1; break;
-      case eCSSProperty_padding_right_value:   paddingRight      = index+1; break;
+      case eCSSProperty_padding_top:           paddingTop    = index+1; break;
+      case eCSSProperty_padding_bottom:        paddingBottom = index+1; break;
+      case eCSSProperty_padding_left_value:    paddingLeft   = index+1; break;
+      case eCSSProperty_padding_right_value:   paddingRight  = index+1; break;
 
-      case eCSSProperty_background_color:      bgColor           = index+1; break;
-      case eCSSProperty_background_image:      bgImage           = index+1; break;
-      case eCSSProperty_background_repeat:     bgRepeat          = index+1; break;
-      case eCSSProperty_background_attachment: bgAttachment      = index+1; break;
-      case eCSSProperty_background_x_position: bgPositionX       = index+1; break;
-      case eCSSProperty_background_y_position: bgPositionY       = index+1; break;
-      default:                                 ;
+      case eCSSProperty_background_color:      bgColor       = index+1; break;
+      case eCSSProperty_background_image:      bgImage       = index+1; break;
+      case eCSSProperty_background_repeat:     bgRepeat      = index+1; break;
+      case eCSSProperty_background_attachment: bgAttachment  = index+1; break;
+      case eCSSProperty_background_x_position: bgPositionX   = index+1; break;
+      case eCSSProperty_background_y_position: bgPositionY   = index+1; break;
+
+      case eCSSProperty_overflow_x:            overflowX     = index+1; break;
+      case eCSSProperty_overflow_y:            overflowY     = index+1; break;
+
+      default: break;
     }
   }
 
@@ -1139,6 +1174,7 @@ nsCSSDeclaration::ToString(nsAString& aString) const
   TryBackgroundShorthand(aString,
                          bgColor, bgImage, bgRepeat, bgAttachment,
                          bgPositionX, bgPositionY);
+  TryOverflowShorthand(aString, overflowX, overflowY);
 
   for (index = 0; index < count; index++) {
     nsCSSProperty property = OrderValueAt(index);
@@ -1214,6 +1250,9 @@ nsCSSDeclaration::ToString(nsAString& aString) const
         break;
       }
 
+      NS_CASE_OUTPUT_PROPERTY_VALUE(eCSSProperty_overflow_x, overflowX)
+      NS_CASE_OUTPUT_PROPERTY_VALUE(eCSSProperty_overflow_y, overflowY)
+
       case eCSSProperty_margin_left_ltr_source:
       case eCSSProperty_margin_left_rtl_source:
       case eCSSProperty_margin_right_ltr_source:
diff --git a/mozilla/content/html/style/src/nsCSSDeclaration.h b/mozilla/content/html/style/src/nsCSSDeclaration.h
index fe7a3bb0d83..ead908df86a 100644
--- a/mozilla/content/html/style/src/nsCSSDeclaration.h
+++ b/mozilla/content/html/style/src/nsCSSDeclaration.h
@@ -190,6 +190,8 @@ private:
   void  UseBackgroundPosition(nsAString & aString,
                               PRInt32 & aBgPositionX,
                               PRInt32 & aBgPositionY) const;
+  void  TryOverflowShorthand(nsAString & aString,
+                             PRInt32 & aOverflowX, PRInt32 & aOverflowY) const;
 
   PRBool   AllPropertiesSameImportance(PRInt32 aFirst, PRInt32 aSecond,
                                        PRInt32 aThird, PRInt32 aFourth,
diff --git a/mozilla/content/html/style/src/nsCSSParser.cpp b/mozilla/content/html/style/src/nsCSSParser.cpp
index 58f254ef2d8..8a92cad5468 100644
--- a/mozilla/content/html/style/src/nsCSSParser.cpp
+++ b/mozilla/content/html/style/src/nsCSSParser.cpp
@@ -261,6 +261,7 @@ protected:
 #ifdef ENABLE_OUTLINE
   PRBool ParseOutline(nsresult& aErrorCode);
 #endif
+  PRBool ParseOverflow(nsresult& aErrorCode);
   PRBool ParsePadding(nsresult& aErrorCode);
   PRBool ParsePause(nsresult& aErrorCode);
   PRBool ParsePlayDuring(nsresult& aErrorCode);
@@ -4024,6 +4025,8 @@ PRBool CSSParserImpl::ParseProperty(nsresult& aErrorCode,
   case eCSSProperty__moz_outline:
     return ParseOutline(aErrorCode);
 #endif
+  case eCSSProperty_overflow:
+    return ParseOverflow(aErrorCode);
   case eCSSProperty_padding:
     return ParsePadding(aErrorCode);
   case eCSSProperty_padding_end:
@@ -4157,6 +4160,7 @@ PRBool CSSParserImpl::ParseSingleValueProperty(nsresult& aErrorCode,
   case eCSSProperty__moz_outline:
   case eCSSProperty__moz_outline_radius:
 #endif
+  case eCSSProperty_overflow:
   case eCSSProperty_padding:
   case eCSSProperty_padding_end:
   case eCSSProperty_padding_left:
@@ -4443,9 +4447,10 @@ PRBool CSSParserImpl::ParseSingleValueProperty(nsresult& aErrorCode,
     return ParseVariant(aErrorCode, aValue, VARIANT_HKL,
                         nsCSSProps::kBorderWidthKTable);
 #endif
-  case eCSSProperty_overflow:
+  case eCSSProperty_overflow_x:
+  case eCSSProperty_overflow_y:
     return ParseVariant(aErrorCode, aValue, VARIANT_AHK,
-                        nsCSSProps::kOverflowKTable);
+                        nsCSSProps::kOverflowSubKTable);
   case eCSSProperty_padding_bottom:
   case eCSSProperty_padding_end_value: // for internal use
   case eCSSProperty_padding_left_value: // for internal use
@@ -5554,6 +5559,33 @@ PRBool CSSParserImpl::ParseOutline(nsresult& aErrorCode)
 }
 #endif
 
+PRBool CSSParserImpl::ParseOverflow(nsresult& aErrorCode)
+{
+  nsCSSValue overflow;
+  if (!ParseVariant(aErrorCode, overflow, VARIANT_AHK,
+                   nsCSSProps::kOverflowKTable) ||
+      !ExpectEndProperty(aErrorCode, PR_TRUE))
+    return PR_FALSE;
+
+  nsCSSValue overflowX(overflow);
+  nsCSSValue overflowY(overflow);
+  if (eCSSUnit_Enumerated == overflow.GetUnit())
+    switch(overflow.GetIntValue()) {
+      case NS_STYLE_OVERFLOW_SCROLLBARS_HORIZONTAL:
+        overflowX.SetIntValue(NS_STYLE_OVERFLOW_SCROLL, eCSSUnit_Enumerated);
+        overflowY.SetIntValue(NS_STYLE_OVERFLOW_HIDDEN, eCSSUnit_Enumerated);
+        break;
+      case NS_STYLE_OVERFLOW_SCROLLBARS_VERTICAL:
+        overflowX.SetIntValue(NS_STYLE_OVERFLOW_HIDDEN, eCSSUnit_Enumerated);
+        overflowY.SetIntValue(NS_STYLE_OVERFLOW_SCROLL, eCSSUnit_Enumerated);
+        break;
+    }
+  AppendValue(eCSSProperty_overflow_x, overflowX);
+  AppendValue(eCSSProperty_overflow_y, overflowY);
+  aErrorCode = NS_OK;
+  return PR_TRUE;
+}
+
 PRBool CSSParserImpl::ParsePadding(nsresult& aErrorCode)
 {
   static const nsCSSProperty kPaddingSideIDs[] = {
diff --git a/mozilla/content/html/style/src/nsCSSStruct.cpp b/mozilla/content/html/style/src/nsCSSStruct.cpp
index 1470519b68b..a4cac3eaa95 100644
--- a/mozilla/content/html/style/src/nsCSSStruct.cpp
+++ b/mozilla/content/html/style/src/nsCSSStruct.cpp
@@ -487,7 +487,8 @@ nsCSSDisplay::nsCSSDisplay(const nsCSSDisplay& aCopy)
     mFloat(aCopy.mFloat),
     mClear(aCopy.mClear),
     mClip(aCopy.mClip),
-    mOverflow(aCopy.mOverflow),
+    mOverflowX(aCopy.mOverflowX),
+    mOverflowY(aCopy.mOverflowY),
     mVisibility(aCopy.mVisibility),
     mOpacity(aCopy.mOpacity),
     // temp fix for bug 24000
@@ -523,7 +524,8 @@ void nsCSSDisplay::List(FILE* out, PRInt32 aIndent) const
   fputs(NS_LossyConvertUCS2toASCII(buffer).get(), out);
   mClip.List(out, eCSSProperty_clip);
   buffer.SetLength(0);
-  mOverflow.AppendToString(buffer, eCSSProperty_overflow);
+  mOverflowX.AppendToString(buffer, eCSSProperty_overflow_x);
+  mOverflowY.AppendToString(buffer, eCSSProperty_overflow_y);
   fputs(NS_LossyConvertUCS2toASCII(buffer).get(), out);
 }
 #endif
diff --git a/mozilla/content/html/style/src/nsCSSStruct.h b/mozilla/content/html/style/src/nsCSSStruct.h
index a5a06ad9d83..ae641fcff59 100644
--- a/mozilla/content/html/style/src/nsCSSStruct.h
+++ b/mozilla/content/html/style/src/nsCSSStruct.h
@@ -234,7 +234,8 @@ struct nsCSSDisplay : public nsCSSStruct  {
   nsCSSValue mFloat;
   nsCSSValue mClear;
   nsCSSRect  mClip;
-  nsCSSValue mOverflow;
+  nsCSSValue mOverflowX;
+  nsCSSValue mOverflowY;
   nsCSSValue mVisibility;
   nsCSSValue mOpacity;
 
diff --git a/mozilla/content/html/style/src/nsComputedDOMStyle.cpp b/mozilla/content/html/style/src/nsComputedDOMStyle.cpp
index af6f875d0f8..dbdd5b85c35 100644
--- a/mozilla/content/html/style/src/nsComputedDOMStyle.cpp
+++ b/mozilla/content/html/style/src/nsComputedDOMStyle.cpp
@@ -2344,10 +2344,56 @@ nsComputedDOMStyle::GetOverflow(nsIFrame *aFrame,
   const nsStyleDisplay* display = nsnull;
   GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display, aFrame);
 
-  if (display && display->mOverflow != NS_STYLE_OVERFLOW_AUTO) {
+  if (display && display->mOverflowX == display->mOverflowY) {
+    if (display->mOverflowX != NS_STYLE_OVERFLOW_AUTO) {
+      const nsAFlatCString& overflow =
+        nsCSSProps::SearchKeywordTable(display->mOverflowX,
+                                       nsCSSProps::kOverflowKTable);
+      val->SetIdent(overflow);
+    } else {
+      val->SetIdent(nsLayoutAtoms::autoAtom);
+    }
+  } // XXX else what?
+
+  return CallQueryInterface(val, aValue);
+}
+
+nsresult
+nsComputedDOMStyle::GetOverflowX(nsIFrame *aFrame,
+                                 nsIDOMCSSValue** aValue)
+{
+  nsROCSSPrimitiveValue* val = GetROCSSPrimitiveValue();
+  NS_ENSURE_TRUE(val, NS_ERROR_OUT_OF_MEMORY);
+
+  const nsStyleDisplay* display = nsnull;
+  GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display, aFrame);
+
+  if (display && display->mOverflowX != NS_STYLE_OVERFLOW_AUTO) {
     const nsAFlatCString& overflow =
-      nsCSSProps::SearchKeywordTable(display->mOverflow,
-                                     nsCSSProps::kOverflowKTable);
+      nsCSSProps::SearchKeywordTable(display->mOverflowX,
+                                     nsCSSProps::kOverflowSubKTable);
+    val->SetIdent(overflow);
+  } else {
+    val->SetIdent(nsLayoutAtoms::autoAtom);
+  }
+
+  return CallQueryInterface(val, aValue);
+}
+
+nsresult
+nsComputedDOMStyle::GetOverflowY(nsIFrame *aFrame,
+                                 nsIDOMCSSValue** aValue)
+{
+  nsROCSSPrimitiveValue* val = GetROCSSPrimitiveValue();
+  NS_ENSURE_TRUE(val, NS_ERROR_OUT_OF_MEMORY);
+
+  const nsStyleDisplay* display = nsnull;
+  GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display, aFrame);
+
+  if (display && display->mOverflowY != NS_STYLE_OVERFLOW_AUTO) {
+    const nsAFlatCString& overflow =
+      nsCSSProps::SearchKeywordTable(display->mOverflowY,
+                                     nsCSSProps::kOverflowSubKTable);
     val->SetIdent(overflow);
   } else {
     val->SetIdent(nsLayoutAtoms::autoAtom);
@@ -3533,6 +3579,8 @@ nsComputedDOMStyle::GetQueryablePropertyMap(PRUint32* aLength)
     // COMPUTED_STYLE_MAP_ENTRY(outline_style,              OutlineStyle),
     // COMPUTED_STYLE_MAP_ENTRY(outline_width,              OutlineWidth),
     COMPUTED_STYLE_MAP_ENTRY(overflow,                      Overflow),
+    COMPUTED_STYLE_MAP_ENTRY(overflow_x,                    OverflowX),
+    COMPUTED_STYLE_MAP_ENTRY(overflow_y,                    OverflowY),
     //// COMPUTED_STYLE_MAP_ENTRY(padding,                  Padding),
     COMPUTED_STYLE_MAP_ENTRY(padding_bottom,                PaddingBottom),
     COMPUTED_STYLE_MAP_ENTRY(padding_left,                  PaddingLeft),
diff --git a/mozilla/content/html/style/src/nsComputedDOMStyle.h b/mozilla/content/html/style/src/nsComputedDOMStyle.h
index f5bff76c134..89ea422be79 100644
--- a/mozilla/content/html/style/src/nsComputedDOMStyle.h
+++ b/mozilla/content/html/style/src/nsComputedDOMStyle.h
@@ -272,6 +272,8 @@ private:
   nsresult GetPosition(nsIFrame *aFrame, nsIDOMCSSValue** aValue);
   nsresult GetClip(nsIFrame *aFrame, nsIDOMCSSValue** aValue);
   nsresult GetOverflow(nsIFrame *aFrame, nsIDOMCSSValue** aValue);
+  nsresult GetOverflowX(nsIFrame *aFrame, nsIDOMCSSValue** aValue);
+  nsresult GetOverflowY(nsIFrame *aFrame, nsIDOMCSSValue** aValue);
 
   /* User interface properties */
   nsresult GetCursor(nsIFrame *aFrame, nsIDOMCSSValue** aValue);
diff --git a/mozilla/content/html/style/src/nsHTMLCSSStyleSheet.cpp b/mozilla/content/html/style/src/nsHTMLCSSStyleSheet.cpp
index cf65efc5a68..0ade20aeea4 100644
--- a/mozilla/content/html/style/src/nsHTMLCSSStyleSheet.cpp
+++ b/mozilla/content/html/style/src/nsHTMLCSSStyleSheet.cpp
@@ -184,7 +184,8 @@ CSSDisablePropsRule::CommonMapRuleInfoInto(nsRuleData* aData)
     aData->mDisplayData->mPosition = staticposition;
 
     nsCSSValue visible(NS_STYLE_OVERFLOW_VISIBLE, eCSSUnit_Enumerated);
-    aData->mDisplayData->mOverflow = visible;
+    aData->mDisplayData->mOverflowX = visible;
+    aData->mDisplayData->mOverflowY = visible;
 
     // Nobody will care about 'break-before' or 'break-after', since
     // they only apply to blocks (assuming we implement them correctly).
diff --git a/mozilla/content/shared/public/nsCSSPropList.h b/mozilla/content/shared/public/nsCSSPropList.h
index cae3293be7e..bdab54964bd 100644
--- a/mozilla/content/shared/public/nsCSSPropList.h
+++ b/mozilla/content/shared/public/nsCSSPropList.h
@@ -406,7 +406,9 @@ CSS_PROP_SHORTHAND(-moz-outline, _moz_outline, MozOutline)  // XXX This is tempo
 CSS_PROP_OUTLINE(-moz-outline-color, _moz_outline_color, MozOutlineColor, Margin, mOutlineColor, eCSSType_Value, PR_FALSE, kOutlineColorKTable) // XXX bug 48973
 CSS_PROP_OUTLINE(-moz-outline-style, _moz_outline_style, MozOutlineStyle, Margin, mOutlineStyle, eCSSType_Value, PR_FALSE, kBorderStyleKTable) // XXX bug 48973
 CSS_PROP_OUTLINE(-moz-outline-width, _moz_outline_width, MozOutlineWidth, Margin, mOutlineWidth, eCSSType_Value, PR_TRUE, kBorderWidthKTable) // XXX bug 48973
-CSS_PROP_DISPLAY(overflow, overflow, Overflow, Display, mOverflow, eCSSType_Value, PR_FALSE, kOverflowKTable)
+CSS_PROP_SHORTHAND(overflow, overflow, Overflow)
+CSS_PROP_DISPLAY(overflow-x, overflow_x, OverflowX, Display, mOverflowX, eCSSType_Value, PR_FALSE, kOverflowSubKTable)
+CSS_PROP_DISPLAY(overflow-y, overflow_y, OverflowY, Display, mOverflowY, eCSSType_Value, PR_FALSE, kOverflowSubKTable)
 CSS_PROP_SHORTHAND(padding, padding, Padding)
 CSS_PROP_PADDING(padding-bottom, padding_bottom, PaddingBottom, Margin, mPadding.mBottom, eCSSType_Value, PR_TRUE, nsnull)
 CSS_PROP_SHORTHAND(-moz-padding-end, padding_end, MozPaddingEnd)
diff --git a/mozilla/content/shared/public/nsCSSProps.h b/mozilla/content/shared/public/nsCSSProps.h
index 0da4a705dcc..57c70d3e45a 100644
--- a/mozilla/content/shared/public/nsCSSProps.h
+++ b/mozilla/content/shared/public/nsCSSProps.h
@@ -149,6 +149,7 @@ public:
   static const PRInt32 kListStyleKTable[];
   static const PRInt32 kOutlineColorKTable[];
   static const PRInt32 kOverflowKTable[];
+  static const PRInt32 kOverflowSubKTable[];
   static const PRInt32 kPageBreakKTable[];
   static const PRInt32 kPageBreakInsideKTable[];
   static const PRInt32 kPageMarksKTable[];
diff --git a/mozilla/content/shared/public/nsStyleStruct.h b/mozilla/content/shared/public/nsStyleStruct.h
index 305c4e2ec01..4d9fdf026d0 100644
--- a/mozilla/content/shared/public/nsStyleStruct.h
+++ b/mozilla/content/shared/public/nsStyleStruct.h
@@ -731,7 +731,8 @@ struct nsStyleDisplay : public nsStyleStruct {
   PRUint8 mBreakType;           // [reset] see nsStyleConsts.h NS_STYLE_CLEAR_*
   PRPackedBool mBreakBefore;    // [reset] 
   PRPackedBool mBreakAfter;     // [reset] 
-  PRUint8   mOverflow;          // [reset] see nsStyleConsts.h
+  PRUint8 mOverflowX;           // [reset] see nsStyleConsts.h
+  PRUint8 mOverflowY;           // [reset] see nsStyleConsts.h
   PRUint8   mClipFlags;         // [reset] see nsStyleConsts.h
   
   PRBool IsBlockLevel() const {return (NS_STYLE_DISPLAY_BLOCK == mDisplay) ||
@@ -747,6 +748,21 @@ struct nsStyleDisplay : public nsStyleStruct {
 
   PRBool IsPositioned() const {return IsAbsolutelyPositioned() ||
                                       (NS_STYLE_POSITION_RELATIVE == mPosition);}
+
+  PRBool IsScrollableOverflow() const {
+    // mOverflowX and mOverflowY always match when one of them is
+    // NS_STYLE_OVERFLOW_VISIBLE or NS_STYLE_OVERFLOW_CLIP.
+    return mOverflowX != NS_STYLE_OVERFLOW_VISIBLE &&
+           mOverflowX != NS_STYLE_OVERFLOW_CLIP;
+  }
+
+  // For table elements that don't support scroll frame creation, we
+  // support 'overflow: hidden' to mean 'overflow: -moz-hidden-unscrollable'.
+  PRBool IsTableClip() const {
+    return mOverflowX == NS_STYLE_OVERFLOW_CLIP ||
+           (mOverflowX == NS_STYLE_OVERFLOW_HIDDEN &&
+            mOverflowY == NS_STYLE_OVERFLOW_HIDDEN);
+  }
 };
 
 struct nsStyleTable: public nsStyleStruct {
diff --git a/mozilla/content/shared/src/nsCSSProps.cpp b/mozilla/content/shared/src/nsCSSProps.cpp
index e90497b114c..e9d144ce36e 100644
--- a/mozilla/content/shared/src/nsCSSProps.cpp
+++ b/mozilla/content/shared/src/nsCSSProps.cpp
@@ -679,6 +679,7 @@ const PRInt32 nsCSSProps::kOverflowKTable[] = {
   eCSSKeyword_visible, NS_STYLE_OVERFLOW_VISIBLE,
   eCSSKeyword_hidden, NS_STYLE_OVERFLOW_HIDDEN,
   eCSSKeyword_scroll, NS_STYLE_OVERFLOW_SCROLL,
+  // Deprecated:
   eCSSKeyword__moz_scrollbars_none, NS_STYLE_OVERFLOW_HIDDEN,
   eCSSKeyword__moz_scrollbars_horizontal, NS_STYLE_OVERFLOW_SCROLLBARS_HORIZONTAL,
   eCSSKeyword__moz_scrollbars_vertical, NS_STYLE_OVERFLOW_SCROLLBARS_VERTICAL,
@@ -686,6 +687,15 @@ const PRInt32 nsCSSProps::kOverflowKTable[] = {
   -1,-1
 };
 
+const PRInt32 nsCSSProps::kOverflowSubKTable[] = {
+  eCSSKeyword_visible, NS_STYLE_OVERFLOW_VISIBLE,
+  eCSSKeyword_hidden, NS_STYLE_OVERFLOW_HIDDEN,
+  eCSSKeyword_scroll, NS_STYLE_OVERFLOW_SCROLL,
+  // Deprecated:
+  eCSSKeyword__moz_hidden_unscrollable, NS_STYLE_OVERFLOW_CLIP,
+  -1,-1
+};
+
 const PRInt32 nsCSSProps::kPageBreakKTable[] = {
   eCSSKeyword_always, NS_STYLE_PAGE_BREAK_ALWAYS,
   eCSSKeyword_avoid, NS_STYLE_PAGE_BREAK_AVOID,
@@ -1316,6 +1326,12 @@ static const nsCSSProperty gMozOutlineSubpropTable[] = {
   eCSSProperty_UNKNOWN
 };
 
+static const nsCSSProperty gOverflowSubpropTable[] = {
+  eCSSProperty_overflow_x,
+  eCSSProperty_overflow_y,
+  eCSSProperty_UNKNOWN
+};
+
 static const nsCSSProperty gPaddingSubpropTable[] = {
   // Code relies on these being in top-right-bottom-left order.
   eCSSProperty_padding_top,
diff --git a/mozilla/content/shared/src/nsStyleStruct.cpp b/mozilla/content/shared/src/nsStyleStruct.cpp
index fe11994fb64..eb4e27f48c2 100644
--- a/mozilla/content/shared/src/nsStyleStruct.cpp
+++ b/mozilla/content/shared/src/nsStyleStruct.cpp
@@ -1102,7 +1102,8 @@ nsStyleDisplay::nsStyleDisplay()
   mBreakType = NS_STYLE_CLEAR_NONE;
   mBreakBefore = PR_FALSE;
   mBreakAfter = PR_FALSE;
-  mOverflow = NS_STYLE_OVERFLOW_VISIBLE;
+  mOverflowX = NS_STYLE_OVERFLOW_VISIBLE;
+  mOverflowY = NS_STYLE_OVERFLOW_VISIBLE;
   mClipFlags = NS_STYLE_CLIP_AUTO;
   mClip.SetRect(0,0,0,0);
   mOpacity = 1.0f;
@@ -1119,7 +1120,8 @@ nsStyleDisplay::nsStyleDisplay(const nsStyleDisplay& aSource)
   mBreakType = aSource.mBreakType;
   mBreakBefore = aSource.mBreakBefore;
   mBreakAfter = aSource.mBreakAfter;
-  mOverflow = aSource.mOverflow;
+  mOverflowX = aSource.mOverflowX;
+  mOverflowY = aSource.mOverflowY;
   mClipFlags = aSource.mClipFlags;
   mClip = aSource.mClip;
   mOpacity = aSource.mOpacity;
@@ -1133,7 +1135,8 @@ nsChangeHint nsStyleDisplay::CalcDifference(const nsStyleDisplay& aOther) const
       || mPosition != aOther.mPosition
       || mDisplay != aOther.mDisplay
       || (mFloats == NS_STYLE_FLOAT_NONE) != (aOther.mFloats == NS_STYLE_FLOAT_NONE)
-      || mOverflow != aOther.mOverflow
+      || mOverflowX != aOther.mOverflowX
+      || mOverflowY != aOther.mOverflowY
       // might need to create a view to handle change from 1.0 to partial opacity
       || (mOpacity != aOther.mOpacity
           && ((mOpacity < 1.0) != (aOther.mOpacity < 1.0))))
diff --git a/mozilla/content/xml/document/src/nsXMLContentSink.cpp b/mozilla/content/xml/document/src/nsXMLContentSink.cpp
index 4c8ba67f5aa..5a87993f2ba 100644
--- a/mozilla/content/xml/document/src/nsXMLContentSink.cpp
+++ b/mozilla/content/xml/document/src/nsXMLContentSink.cpp
@@ -78,7 +78,6 @@
 #include "prlog.h"
 #include "prmem.h"
 #include "nsParserUtils.h"
-#include "nsIScrollable.h"
 #include "nsRect.h"
 #include "nsGenericElement.h"
 #include "nsIWebNavigation.h"
@@ -832,12 +831,6 @@ nsXMLContentSink::PopContent()
 void
 nsXMLContentSink::StartLayout()
 {
-  // Reset scrolling to default settings for this shell.
-  // This must happen before the initial reflow, when we create the root frame
-  nsCOMPtr<nsIScrollable> scrollableContainer(do_QueryInterface(mDocShell));
-  if (scrollableContainer) {
-    scrollableContainer->ResetScrollbarPreferences();
-  }
   PRBool topLevelFrameset = PR_FALSE;
   nsCOMPtr<nsIDocShellTreeItem> docShellAsItem(do_QueryInterface(mDocShell));
   if (docShellAsItem) {
diff --git a/mozilla/docshell/base/nsDocShell.cpp b/mozilla/docshell/base/nsDocShell.cpp
index 226e5153b69..2499b817d0e 100644
--- a/mozilla/docshell/base/nsDocShell.cpp
+++ b/mozilla/docshell/base/nsDocShell.cpp
@@ -268,8 +268,7 @@ nsDocShell::nsDocShell():
     mMarginHeight(0),
     mItemType(typeContent),
     mContentListener(nsnull),
-    mCurrentScrollbarPref(-1, -1),
-    mDefaultScrollbarPref(-1, -1),
+    mDefaultScrollbarPref(Scrollbar_Auto, Scrollbar_Auto),
     mEditorData(nsnull),
     mParent(nsnull),
     mTreeOwner(nsnull),
@@ -3652,29 +3651,6 @@ nsDocShell::SetScrollRangeEx(PRInt32 minHorizontalPos,
     return NS_ERROR_FAILURE;
 }
 
-// Get scroll setting for this document only
-//
-// One important client is nsCSSFrameConstructor::ConstructRootFrame()
-NS_IMETHODIMP
-nsDocShell::GetCurrentScrollbarPreferences(PRInt32 scrollOrientation,
-                                           PRInt32 * scrollbarPref)
-{
-    NS_ENSURE_ARG_POINTER(scrollbarPref);
-    switch (scrollOrientation) {
-    case ScrollOrientation_X:
-        *scrollbarPref = mCurrentScrollbarPref.x;
-        return NS_OK;
-
-    case ScrollOrientation_Y:
-        *scrollbarPref = mCurrentScrollbarPref.y;
-        return NS_OK;
-
-    default:
-        NS_ENSURE_TRUE(PR_FALSE, NS_ERROR_INVALID_ARG);
-    }
-    return NS_ERROR_FAILURE;
-}
-
 // This returns setting for all documents in this webshell
 NS_IMETHODIMP
 nsDocShell::GetDefaultScrollbarPreferences(PRInt32 scrollOrientation,
@@ -3696,39 +3672,14 @@ nsDocShell::GetDefaultScrollbarPreferences(PRInt32 scrollOrientation,
     return NS_ERROR_FAILURE;
 }
 
-// Set scrolling preference for this document only.
+// Set scrolling preference for all documents in this shell
 //
 // There are three possible values stored in the shell:
-//  1) NS_STYLE_OVERFLOW_HIDDEN = no scrollbars
-//  2) NS_STYLE_OVERFLOW_AUTO = scrollbars appear if needed
-//  3) NS_STYLE_OVERFLOW_SCROLL = scrollbars always
+//  1) NS_STYLE_OVERFLOW_HIDDEN = no scrollbar
+//  2) NS_STYLE_OVERFLOW_AUTO = scrollbar appears if the document
+//     being displayed would normally have scrollbar
+//  3) NS_STYLE_OVERFLOW_SCROLL = scrollbar always appears
 //
-// XXX Currently OVERFLOW_SCROLL isn't honored,
-//     as it is not implemented by Gfx scrollbars
-// XXX setting has no effect after the root frame is created
-//     as it is not implemented by Gfx scrollbars
-//
-// One important client is HTMLContentSink::StartLayout()
-NS_IMETHODIMP
-nsDocShell::SetCurrentScrollbarPreferences(PRInt32 scrollOrientation,
-                                           PRInt32 scrollbarPref)
-{
-    switch (scrollOrientation) {
-    case ScrollOrientation_X:
-        mCurrentScrollbarPref.x = scrollbarPref;
-        return NS_OK;
-
-    case ScrollOrientation_Y:
-        mCurrentScrollbarPref.y = scrollbarPref;
-        return NS_OK;
-
-    default:
-        NS_ENSURE_TRUE(PR_FALSE, NS_ERROR_INVALID_ARG);
-    }
-    return NS_ERROR_FAILURE;
-}
-
-// Set scrolling preference for all documents in this shell
 // One important client is nsHTMLFrameInnerFrame::CreateWebShell()
 NS_IMETHODIMP
 nsDocShell::SetDefaultScrollbarPreferences(PRInt32 scrollOrientation,
@@ -3749,19 +3700,6 @@ nsDocShell::SetDefaultScrollbarPreferences(PRInt32 scrollOrientation,
     return NS_ERROR_FAILURE;
 }
 
-// Reset 'current' scrollbar settings to 'default'.
-// This must be called before every document load or else
-// frameset scrollbar settings (e.g. <IFRAME SCROLLING="no">
-// will not be preserved.
-//
-// One important client is HTMLContentSink::StartLayout()
-NS_IMETHODIMP
-nsDocShell::ResetScrollbarPreferences()
-{
-    mCurrentScrollbarPref = mDefaultScrollbarPref;
-    return NS_OK;
-}
-
 NS_IMETHODIMP
 nsDocShell::GetScrollbarVisibility(PRBool * verticalVisible,
                                    PRBool * horizontalVisible)
diff --git a/mozilla/docshell/base/nsDocShell.h b/mozilla/docshell/base/nsDocShell.h
index c2501973f1f..3e78a82c90d 100644
--- a/mozilla/docshell/base/nsDocShell.h
+++ b/mozilla/docshell/base/nsDocShell.h
@@ -408,7 +408,6 @@ protected:
     nsCOMPtr<nsIGlobalHistory2> mGlobalHistory;
     nsCOMPtr<nsISupports>      mLoadCookie; // the load cookie associated with the window context.
     nsCOMPtr<nsIWebBrowserFind> mFind;
-    nsPoint                    mCurrentScrollbarPref; // this document only
     nsPoint                    mDefaultScrollbarPref; // persistent across doc loads
     // Reference to the SHEntry for this docshell until the page is destroyed.
     // Somebody give me better name
diff --git a/mozilla/docshell/base/nsIScrollable.idl b/mozilla/docshell/base/nsIScrollable.idl
index e9847996935..909fc5a39e7 100644
--- a/mozilla/docshell/base/nsIScrollable.idl
+++ b/mozilla/docshell/base/nsIScrollable.idl
@@ -48,20 +48,20 @@
  * min and the max. 
  */
 
-[scriptable, uuid(61792520-82C2-11d3-AF76-00A024FFC08C)]
+[scriptable, uuid(919e792a-6490-40b8-bba5-f9e9ad5640c8)]
 interface nsIScrollable : nsISupports
 {
 	/*
 	Constants declaring the two scroll orientations a scroll bar can be in.
-	ScrollOrientation_X - Vertical scrolling.  When passing this in to a scroll position
-		method you are requesting or setting the positions for the vertical
-		scroll bar.
-	ScrollOrientation_Y - Horizontal scrolling.  When passing this in to a scroll
-		position you are requesting or setting the positions for the horizontal
-		scroll bar.
+        ScrollOrientation_X - Horizontal scrolling.  When passing this
+                in to a scroll position method you are requesting or
+                setting the positions for the horizontal scroll bar.
+        ScrollOrientation_Y - Vertical scrolling.  When passing this
+                in to a scroll position you are requesting or setting
+                the positions for the vertical scroll bar.
 	*/
-	const long ScrollOrientation_Y = 1;
-	const long ScrollOrientation_X = 2;
+	const long ScrollOrientation_X = 1;
+	const long ScrollOrientation_Y = 2;
 
 	/*
 	Retrieves or Sets the current thumb position to the curPos passed in for the
@@ -71,7 +71,7 @@ interface nsIScrollable : nsISupports
 				NS_ERROR_INVALID_ARG - returned when curPos is not within the
 					minPos and maxPos.
 	*/
-	void getCurScrollPos(in long scrollOrientation, out long curPos);
+	long getCurScrollPos(in long scrollOrientation);
 	void setCurScrollPos(in long scrollOrientation, in long curPos);
 
 	/*
@@ -114,11 +114,8 @@ interface nsIScrollable : nsISupports
 	default is 'scrolling preference for all documents in this shell'
 	resetScrollbarPreferences resets current to default
 	*/
-	void getCurrentScrollbarPreferences(in long scrollOrientation, out long scrollbarPref);
-	void setCurrentScrollbarPreferences(in long scrollOrientation, in long scrollbarPref);
-	void getDefaultScrollbarPreferences(in long scrollOrientation, out long scrollbarPref);
+	long getDefaultScrollbarPreferences(in long scrollOrientation);
 	void setDefaultScrollbarPreferences(in long scrollOrientation, in long scrollbarPref);
-	void resetScrollbarPreferences();
 
 	/*
 	Get information about whether the vertical and horizontal scrollbars are
@@ -128,4 +125,4 @@ interface nsIScrollable : nsISupports
 	*/
 	void getScrollbarVisibility(out boolean verticalVisible, 
 		out boolean horizontalVisible);
-};
\ No newline at end of file
+};
diff --git a/mozilla/dom/public/idl/css/nsIDOMCSS2Properties.idl b/mozilla/dom/public/idl/css/nsIDOMCSS2Properties.idl
index da6eda5a6d9..d7d71bd2b9a 100644
--- a/mozilla/dom/public/idl/css/nsIDOMCSS2Properties.idl
+++ b/mozilla/dom/public/idl/css/nsIDOMCSS2Properties.idl
@@ -563,4 +563,11 @@ interface nsIDOMNSCSS2Properties : nsIDOMCSS2Properties
            attribute DOMString        opacity;
                                         // raises(DOMException) on setting
 
+           /* Mozilla extensions */
+           attribute DOMString        overflowX;
+                                        // raises(DOMException) on setting
+
+           attribute DOMString        overflowY;
+                                        // raises(DOMException) on setting
+
 };
diff --git a/mozilla/dom/src/base/nsBarProps.cpp b/mozilla/dom/src/base/nsBarProps.cpp
index 6eb053d02c0..4bb25ae7406 100644
--- a/mozilla/dom/src/base/nsBarProps.cpp
+++ b/mozilla/dom/src/base/nsBarProps.cpp
@@ -275,15 +275,14 @@ ScrollbarsPropImpl::GetVisible(PRBool *aVisible)
       do_QueryInterface(mDOMWindow->GetDocShell());
 
     if (scroller) {
-      PRInt32 prefValue = aVisible ? NS_STYLE_OVERFLOW_AUTO :
-                                     NS_STYLE_OVERFLOW_HIDDEN;
+      PRInt32 prefValue;
       scroller->GetDefaultScrollbarPreferences(
                   nsIScrollable::ScrollOrientation_Y, &prefValue);
-      if (prefValue == NS_STYLE_OVERFLOW_HIDDEN) // try the other way
+      if (prefValue == nsIScrollable::Scrollbar_Never) // try the other way
         scroller->GetDefaultScrollbarPreferences(
                     nsIScrollable::ScrollOrientation_X, &prefValue);
 
-      if (prefValue == NS_STYLE_OVERFLOW_HIDDEN)
+      if (prefValue == nsIScrollable::Scrollbar_Never)
         *aVisible = PR_FALSE;
     }
   }
@@ -307,8 +306,8 @@ ScrollbarsPropImpl::SetVisible(PRBool aVisible)
       do_QueryInterface(mDOMWindow->GetDocShell());
 
     if (scroller) {
-      PRInt32 prefValue = aVisible ? NS_STYLE_OVERFLOW_AUTO :
-                                     NS_STYLE_OVERFLOW_HIDDEN;
+      PRInt32 prefValue = aVisible ? nsIScrollable::Scrollbar_Auto :
+                                     nsIScrollable::Scrollbar_Never ;
       scroller->SetDefaultScrollbarPreferences(
                   nsIScrollable::ScrollOrientation_Y, prefValue);
       scroller->SetDefaultScrollbarPreferences(
diff --git a/mozilla/embedding/browser/webBrowser/nsWebBrowser.cpp b/mozilla/embedding/browser/webBrowser/nsWebBrowser.cpp
index 18474270d13..eec086f10e9 100644
--- a/mozilla/embedding/browser/webBrowser/nsWebBrowser.cpp
+++ b/mozilla/embedding/browser/webBrowser/nsWebBrowser.cpp
@@ -1524,15 +1524,6 @@ NS_IMETHODIMP nsWebBrowser::SetScrollRangeEx(PRInt32 aMinHorizontalPos,
       aMaxHorizontalPos, aMinVerticalPos, aMaxVerticalPos);
 }
 
-NS_IMETHODIMP nsWebBrowser::GetCurrentScrollbarPreferences(PRInt32 aScrollOrientation,
-   PRInt32* aScrollbarPref)
-{
-   NS_ENSURE_STATE(mDocShell);
-
-   return mDocShellAsScrollable->GetCurrentScrollbarPreferences(aScrollOrientation,
-      aScrollbarPref);
-}
-
 NS_IMETHODIMP nsWebBrowser::GetDefaultScrollbarPreferences(PRInt32 aScrollOrientation,
    PRInt32* aScrollbarPref)
 {
@@ -1542,16 +1533,6 @@ NS_IMETHODIMP nsWebBrowser::GetDefaultScrollbarPreferences(PRInt32 aScrollOrient
       aScrollbarPref);
 }
 
-NS_IMETHODIMP nsWebBrowser::SetCurrentScrollbarPreferences(PRInt32 aScrollOrientation,
-   PRInt32 aScrollbarPref)
-{
-   NS_ENSURE_STATE(mDocShell);
-
-   return mDocShellAsScrollable->SetCurrentScrollbarPreferences(aScrollOrientation,
-      aScrollbarPref);
-
-}
-
 NS_IMETHODIMP nsWebBrowser::SetDefaultScrollbarPreferences(PRInt32 aScrollOrientation,
    PRInt32 aScrollbarPref)
 {
@@ -1561,13 +1542,6 @@ NS_IMETHODIMP nsWebBrowser::SetDefaultScrollbarPreferences(PRInt32 aScrollOrient
       aScrollbarPref);
 }
 
-NS_IMETHODIMP nsWebBrowser::ResetScrollbarPreferences()
-{
-   NS_ENSURE_STATE(mDocShell);
-
-   return mDocShellAsScrollable->ResetScrollbarPreferences();
-}
-
 NS_IMETHODIMP nsWebBrowser::GetScrollbarVisibility(PRBool* aVerticalVisible,
    PRBool* aHorizontalVisible)
 {
diff --git a/mozilla/layout/base/nsCSSFrameConstructor.cpp b/mozilla/layout/base/nsCSSFrameConstructor.cpp
index e9cc62a2bc2..8831a728542 100644
--- a/mozilla/layout/base/nsCSSFrameConstructor.cpp
+++ b/mozilla/layout/base/nsCSSFrameConstructor.cpp
@@ -2708,7 +2708,7 @@ nsCSSFrameConstructor::ConstructTableRowGroupFrame(nsIPresShell*            aPre
   rv = aTableCreator.CreateTableRowGroupFrame(&aNewFrame);
 
   nsIFrame* scrollFrame = nsnull;
-  if (IsScrollable(aPresContext, styleDisplay)) {
+  if (styleDisplay->IsScrollableOverflow()) {
     // Create an area container for the frame
     BuildScrollFrame(aPresShell, aPresContext, aState, aContent, aStyleContext, 
                      aNewFrame, parentFrame, nsnull, scrollFrame, aStyleContext);
@@ -3341,6 +3341,21 @@ nsCSSFrameConstructor::ConstructDocElementTableFrame(nsIPresShell*        aPresS
   return NS_OK;
 }
 
+static PRBool CheckOverflow(nsPresContext* aPresContext,
+                            const nsStyleDisplay* aDisplay)
+{
+  if (aDisplay->mOverflowX == NS_STYLE_OVERFLOW_VISIBLE)
+    return PR_FALSE;
+
+  if (aDisplay->mOverflowX == NS_STYLE_OVERFLOW_CLIP)
+    aPresContext->SetViewportOverflowOverride(NS_STYLE_OVERFLOW_HIDDEN,
+                                              NS_STYLE_OVERFLOW_HIDDEN);
+  else
+    aPresContext->SetViewportOverflowOverride(aDisplay->mOverflowX,
+                                              aDisplay->mOverflowY);
+  return PR_TRUE;
+}
+
 /**
  * This checks the root element and the HTML BODY, if any, for an "overflow" property
  * that should be applied to the viewport. If one is found then we return the
@@ -3354,7 +3369,8 @@ nsIContent*
 nsCSSFrameConstructor::PropagateScrollToViewport(nsPresContext* aPresContext)
 {
   // Set default
-  aPresContext->SetViewportOverflowOverride(NS_STYLE_OVERFLOW_AUTO);
+  aPresContext->SetViewportOverflowOverride(NS_STYLE_OVERFLOW_AUTO,
+                                            NS_STYLE_OVERFLOW_AUTO);
 
   // We never mess with the viewport scroll state
   // when printing or in print preview
@@ -3366,14 +3382,12 @@ nsCSSFrameConstructor::PropagateScrollToViewport(nsPresContext* aPresContext)
 
   // Check the style on the document root element
   nsStyleSet *styleSet = aPresContext->PresShell()->StyleSet();
-  nsRefPtr<nsStyleContext> styleContext;
-  styleContext = styleSet->ResolveStyleFor(docElement, nsnull);
-  if (!styleContext) {
+  nsRefPtr<nsStyleContext> rootStyle;
+  rootStyle = styleSet->ResolveStyleFor(docElement, nsnull);
+  if (!rootStyle) {
     return nsnull;
   }
-  const nsStyleDisplay* display = styleContext->GetStyleDisplay();
-  if (display->mOverflow != NS_STYLE_OVERFLOW_VISIBLE) {
-    aPresContext->SetViewportOverflowOverride(display->mOverflow);
+  if (CheckOverflow(aPresContext, rootStyle->GetStyleDisplay())) {
     // tell caller we stole the overflow style from the root element
     return docElement;
   }
@@ -3399,15 +3413,13 @@ nsCSSFrameConstructor::PropagateScrollToViewport(nsPresContext* aPresContext)
     return nsnull;
   }
 
-  nsRefPtr<nsStyleContext> bodyContext;
-  bodyContext = styleSet->ResolveStyleFor(bodyElement, styleContext);
-  if (!bodyContext) {
+  nsRefPtr<nsStyleContext> bodyStyle;
+  bodyStyle = styleSet->ResolveStyleFor(bodyElement, rootStyle);
+  if (!bodyStyle) {
     return nsnull;
   }
 
-  display = bodyContext->GetStyleDisplay();
-  if (display->mOverflow != NS_STYLE_OVERFLOW_VISIBLE) {
-    aPresContext->SetViewportOverflowOverride(display->mOverflow);
+  if (CheckOverflow(aPresContext, bodyStyle->GetStyleDisplay())) {
     // tell caller we stole the overflow style from the body element
     return bodyElement;
   }
@@ -3521,7 +3533,7 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
 
   // The document root should not be scrollable in any paginated context,
   // even in print preview.
-  PRBool isScrollable = IsScrollable(aPresContext, display)
+  PRBool isScrollable = display->IsScrollableOverflow()
     && !aPresContext->IsPaginated()
     && !propagatedScrollToViewport;
 
@@ -3796,7 +3808,6 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
   // for print-preview, but not when printing), then create a scroll frame that
   // will act as the scrolling mechanism for the viewport. 
   // XXX Do we even need a viewport when printing to a printer?
-  PRBool isScrollable = PR_TRUE;
 
   //isScrollable = PR_FALSE;
 
@@ -3809,8 +3820,6 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
   //  2) NS_STYLE_OVERFLOW_AUTO = scrollbars appear if needed
   //  3) NS_STYLE_OVERFLOW_SCROLL = scrollbars always
   // Only need to create a scroll frame/view for cases 2 and 3.
-  // Currently OVERFLOW_SCROLL isn't honored, as
-  // scrollportview::SetScrollPref is not implemented.
 
   PRBool isHTML = aDocElement->IsContentOfType(nsIContent::eHTML);
   PRBool isXUL = PR_FALSE;
@@ -3820,28 +3829,13 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
   }
 
   // Never create scrollbars for XUL documents
-#ifdef MOZ_XUL
-  if (isXUL) {
-    isScrollable = PR_FALSE;
-  } else 
-#endif
-  {
-    nsresult rv;
-    if (aPresContext) {
-      nsCOMPtr<nsISupports> container = aPresContext->GetContainer();
-      if (container) {
-        nsCOMPtr<nsIScrollable> scrollableContainer = do_QueryInterface(container, &rv);
-        if (NS_SUCCEEDED(rv) && scrollableContainer) {
-          PRInt32 scrolling = -1;
-          // XXX We should get prefs for X and Y and deal with these independently!
-          scrollableContainer->GetCurrentScrollbarPreferences(nsIScrollable::ScrollOrientation_Y,&scrolling);
-          if (NS_STYLE_OVERFLOW_HIDDEN == scrolling) {
-            isScrollable = PR_FALSE;
-          }
-          // XXX NS_STYLE_OVERFLOW_SCROLL should create 'always on' scrollbars
-        }
-      }
-    }
+  PRBool isScrollable = !isXUL;
+
+  // Never create scrollbars for frameset documents.
+  if (isHTML) {
+    nsCOMPtr<nsIHTMLDocument> htmlDoc = do_QueryInterface(mDocument);
+    if (htmlDoc && htmlDoc->GetIsFrameset())
+      isScrollable = PR_FALSE;
   }
 
   if (isPaginated) {
@@ -5480,7 +5474,7 @@ nsCSSFrameConstructor::ConstructXULFrame(nsIPresShell*            aPresShell,
         }
 
         // Boxes can scroll.
-        if (IsScrollable(aPresContext, display)) {
+        if (display->IsScrollableOverflow()) {
 
           nsIFrame* scrollPort = nsnull;
           if (listboxScrollPort) {
@@ -5580,7 +5574,7 @@ nsCSSFrameConstructor::ConstructXULFrame(nsIPresShell*            aPresShell,
 #endif
     }
 
-    if (mayBeScrollable && IsScrollable(aPresContext, display)) {
+    if (mayBeScrollable && display->IsScrollableOverflow()) {
       // set the top to be the newly created scrollframe
       BuildScrollFrame(aPresShell, aPresContext, aState, aContent,
                        aStyleContext, newFrame, aParentFrame, nsnull,
@@ -6088,7 +6082,7 @@ nsCSSFrameConstructor::ConstructFrameByDisplayType(nsIPresShell*            aPre
   // XXX Ignore tables for the time being
   if (aDisplay->IsBlockLevel() &&
       aDisplay->mDisplay != NS_STYLE_DISPLAY_TABLE &&
-      IsScrollable(aPresContext, aDisplay) &&
+      aDisplay->IsScrollableOverflow() &&
       !propagatedScrollToViewport) {
 
     if (!pseudoParent && !aState.mPseudoFrames.IsEmpty()) { // process pending pseudo frames
@@ -6494,25 +6488,6 @@ nsCSSFrameConstructor::ConstructFrameByDisplayType(nsIPresShell*            aPre
   return rv;
 }
 
-
-PRBool
-nsCSSFrameConstructor::IsScrollable(nsPresContext*       aPresContext,
-                                    const nsStyleDisplay* aDisplay)
-{
-  // For the time being it's scrollable if the overflow property is auto or
-  // scroll, regardless of whether the width or height is fixed in size
-  switch (aDisplay->mOverflow) {
-    case NS_STYLE_OVERFLOW_SCROLL:
-    case NS_STYLE_OVERFLOW_AUTO:
-    case NS_STYLE_OVERFLOW_HIDDEN:
-    case NS_STYLE_OVERFLOW_SCROLLBARS_HORIZONTAL:
-    case NS_STYLE_OVERFLOW_SCROLLBARS_VERTICAL:
-      return PR_TRUE;
-  }
-  return PR_FALSE;
-}
-
-
 nsresult 
 nsCSSFrameConstructor::InitAndRestoreFrame(nsPresContext*          aPresContext,
                                            nsFrameConstructorState& aState,
diff --git a/mozilla/layout/base/nsCSSFrameConstructor.h b/mozilla/layout/base/nsCSSFrameConstructor.h
index 229bc774c9e..e6803adac13 100644
--- a/mozilla/layout/base/nsCSSFrameConstructor.h
+++ b/mozilla/layout/base/nsCSSFrameConstructor.h
@@ -685,8 +685,6 @@ private:
                                       nsIContent*               aChild,
                                       nsIDOMHTMLSelectElement*  aSelectElement);
 
-  PRBool IsScrollable(nsPresContext* aPresContext, const nsStyleDisplay* aDisplay);
-
   nsIFrame* GetFrameFor(nsIPresShell*   aPresShell,
                         nsPresContext* aPresContext,
                         nsIContent*     aContent);
diff --git a/mozilla/layout/base/nsDocumentViewer.cpp b/mozilla/layout/base/nsDocumentViewer.cpp
index 06c9ec4b1ea..887f89e66e5 100644
--- a/mozilla/layout/base/nsDocumentViewer.cpp
+++ b/mozilla/layout/base/nsDocumentViewer.cpp
@@ -120,7 +120,7 @@
 #include "nsIFocusController.h"
 
 #include "nsIScrollableView.h"
-#include "nsIScrollable.h"
+#include "nsIHTMLDocument.h"
 #include "nsITimelineService.h"
 #include "nsGfxCIID.h"
 
@@ -678,23 +678,11 @@ DocumentViewerImpl::InitPresentationStuff(PRBool aDoInitialReflow)
   mViewManager->SetDefaultBackgroundColor(mPresContext->DefaultBackgroundColor());
 
   if (aDoInitialReflow) {
-    nsCOMPtr<nsIScrollable> sc = do_QueryInterface(mContainer);
-
-    if (sc) {
-      nsCOMPtr<nsIDOMHTMLFrameSetElement> frameset(do_QueryInterface(mDocument->GetRootContent()));
-
-      if (frameset) {
-        // If this is a frameset (i.e. not a frame) then we never want
-        // scrollbars on it, the scrollbars go inside the frames
-        // inside the frameset...
-
-        sc->SetCurrentScrollbarPreferences(nsIScrollable::ScrollOrientation_Y,
-                                           NS_STYLE_OVERFLOW_HIDDEN);
-        sc->SetCurrentScrollbarPreferences(nsIScrollable::ScrollOrientation_X,
-                                           NS_STYLE_OVERFLOW_HIDDEN);
-      } else {
-        sc->ResetScrollbarPreferences();
-      }
+    nsCOMPtr<nsIHTMLDocument> htmlDoc = do_QueryInterface(mDocument);
+    if (htmlDoc) {
+      nsCOMPtr<nsIDOMHTMLFrameSetElement> frameset =
+        do_QueryInterface(mDocument->GetRootContent());
+      htmlDoc->SetIsFrameset(frameset != nsnull);
     }
 
     // Initial reflow
diff --git a/mozilla/layout/base/nsPresContext.cpp b/mozilla/layout/base/nsPresContext.cpp
index e3626a5629f..e28e6ff61cd 100644
--- a/mozilla/layout/base/nsPresContext.cpp
+++ b/mozilla/layout/base/nsPresContext.cpp
@@ -140,6 +140,7 @@ static NS_DEFINE_CID(kSelectionImageService, NS_SELECTIONIMAGESERVICE_CID);
 
 nsPresContext::nsPresContext(nsPresContextType aType)
   : mType(aType),
+    mViewportStyleOverflow(NS_STYLE_OVERFLOW_AUTO, NS_STYLE_OVERFLOW_AUTO),
     mCompatibilityMode(eCompatibility_FullStandards),
     mImageAnimationModePref(imgIContainer::kNormalAnimMode),
     mDefaultVariableFont("serif", NS_FONT_STYLE_NORMAL, NS_FONT_VARIANT_NORMAL,
@@ -165,8 +166,6 @@ nsPresContext::nsPresContext(nsPresContextType aType)
   SetBackgroundImageDraw(PR_TRUE);		// always draw the background
   SetBackgroundColorDraw(PR_TRUE);
 
-  mViewportStyleOverflow = NS_STYLE_OVERFLOW_AUTO;
-
   mBackgroundColor = NS_RGB(0xFF, 0xFF, 0xFF);
   
   mUseDocumentColors = PR_TRUE;
diff --git a/mozilla/layout/base/nsPresContext.h b/mozilla/layout/base/nsPresContext.h
index 9427646f649..8aa8364312f 100644
--- a/mozilla/layout/base/nsPresContext.h
+++ b/mozilla/layout/base/nsPresContext.h
@@ -431,11 +431,22 @@ public:
     return mLanguageSpecificTransformType;
   }
 
-  void SetViewportOverflowOverride(PRUint8 aStyle)
+  struct ScrollbarStyles {
+    // Always one of NS_STYLE_OVERFLOW_SCROLL, NS_STYLE_OVERFLOW_HIDDEN,
+    // or NS_STYLE_OVERFLOW_AUTO.
+    PRUint8 mHorizontal, mVertical;
+    ScrollbarStyles(PRUint8 h, PRUint8 v) : mHorizontal(h), mVertical(v) {}
+    ScrollbarStyles() {}
+  };
+  void SetViewportOverflowOverride(PRUint8 aX, PRUint8 aY)
   {
-    mViewportStyleOverflow = aStyle;
+    mViewportStyleOverflow.mHorizontal = aX;
+    mViewportStyleOverflow.mVertical = aY;
+  }
+  ScrollbarStyles GetViewportOverflowOverride()
+  {
+    return mViewportStyleOverflow;
   }
-  PRUint8 GetViewportOverflowOverride() { return mViewportStyleOverflow; }
 
   /**
    * Set and get methods for controling the background drawing
@@ -644,8 +655,8 @@ protected:
   nscolor               mFocusBackgroundColor;
   nscolor               mFocusTextColor;
 
+  ScrollbarStyles       mViewportStyleOverflow;
   PRUint8               mFocusRingWidth;
-  PRUint8               mViewportStyleOverflow;
 
   nsCompatibility       mCompatibilityMode;
   PRUint16              mImageAnimationMode;
diff --git a/mozilla/layout/base/public/nsIScrollableFrame.h b/mozilla/layout/base/public/nsIScrollableFrame.h
index 270a5445a14..be0db689a87 100644
--- a/mozilla/layout/base/public/nsIScrollableFrame.h
+++ b/mozilla/layout/base/public/nsIScrollableFrame.h
@@ -42,10 +42,10 @@
 #include "nsCoord.h"
 #include "nsIViewManager.h"
 #include "nsIScrollableViewProvider.h"
+#include "nsPresContext.h"
 
 class nsIFrame;
 class nsIBox;
-class nsPresContext;
 class nsBoxLayoutState;
 
 // IID for the nsIScrollableFrame interface
@@ -56,14 +56,6 @@ class nsBoxLayoutState;
 class nsIScrollableFrame : public nsIScrollableViewProvider {
 public:
 
-  enum nsScrollPref {
-    Auto = 0,
-    NeverScroll,
-    AlwaysScroll,
-    AlwaysScrollVertical,
-    AlwaysScrollHorizontal
-  };
-
   NS_DEFINE_STATIC_IID_ACCESSOR(NS_ISCROLLABLE_FRAME_IID)
 
   /**
@@ -73,13 +65,7 @@ public:
   NS_IMETHOD GetScrolledFrame(nsPresContext* aPresContext,
                               nsIFrame *&aScrolledFrame) const = 0;
 
-  struct ScrollbarStyles {
-    // one of NS_STYLE_OVERFLOW_SCROLL, NS_STYLE_OVERFLOW_HIDDEN,
-    // NS_STYLE_OVERFLOW_VISIBLE, NS_STYLE_OVERFLOW_AUTO
-    PRInt32 mHorizontal;
-    PRInt32 mVertical;
-    ScrollbarStyles(PRInt32 h, PRInt32 v) : mHorizontal(h), mVertical(v) {}
-  };
+  typedef nsPresContext::ScrollbarStyles ScrollbarStyles;
 
   virtual ScrollbarStyles GetScrollbarStyles() const = 0;
 
@@ -95,13 +81,6 @@ public:
    */
   virtual nsMargin GetDesiredScrollbarSizes(nsBoxLayoutState* aState) = 0;
 
-  /**
-   * Query whether scroll bars should be displayed all the time, never or
-   * only when necessary.
-   * @return current scrollbar selection
-   */
-  NS_IMETHOD  GetScrollPreference(nsPresContext* aPresContext, nsScrollPref* aScrollPreference) const = 0;
-
   /**
    * Get the position of the scrolled view.
    */
@@ -120,15 +99,6 @@ public:
 
   NS_IMETHOD GetScrollableView(nsPresContext* aContext, nsIScrollableView** aResult)=0;
 
-
-  /**
-   * Set information about whether the vertical and horizontal scrollbars
-   * are currently visible
-   */
-  NS_IMETHOD SetScrollbarVisibility(nsPresContext* aPresContext,
-                                    PRBool aVerticalVisible,
-                                    PRBool aHorizontalVisible) = 0;
-
   NS_IMETHOD GetScrollbarBox(PRBool aVertical, nsIBox** aResult) = 0;
 
   NS_IMETHOD CurPosAttributeChanged(nsPresContext* aPresContext,
diff --git a/mozilla/layout/base/public/nsPresContext.h b/mozilla/layout/base/public/nsPresContext.h
index 9427646f649..8aa8364312f 100644
--- a/mozilla/layout/base/public/nsPresContext.h
+++ b/mozilla/layout/base/public/nsPresContext.h
@@ -431,11 +431,22 @@ public:
     return mLanguageSpecificTransformType;
   }
 
-  void SetViewportOverflowOverride(PRUint8 aStyle)
+  struct ScrollbarStyles {
+    // Always one of NS_STYLE_OVERFLOW_SCROLL, NS_STYLE_OVERFLOW_HIDDEN,
+    // or NS_STYLE_OVERFLOW_AUTO.
+    PRUint8 mHorizontal, mVertical;
+    ScrollbarStyles(PRUint8 h, PRUint8 v) : mHorizontal(h), mVertical(v) {}
+    ScrollbarStyles() {}
+  };
+  void SetViewportOverflowOverride(PRUint8 aX, PRUint8 aY)
   {
-    mViewportStyleOverflow = aStyle;
+    mViewportStyleOverflow.mHorizontal = aX;
+    mViewportStyleOverflow.mVertical = aY;
+  }
+  ScrollbarStyles GetViewportOverflowOverride()
+  {
+    return mViewportStyleOverflow;
   }
-  PRUint8 GetViewportOverflowOverride() { return mViewportStyleOverflow; }
 
   /**
    * Set and get methods for controling the background drawing
@@ -644,8 +655,8 @@ protected:
   nscolor               mFocusBackgroundColor;
   nscolor               mFocusTextColor;
 
+  ScrollbarStyles       mViewportStyleOverflow;
   PRUint8               mFocusRingWidth;
-  PRUint8               mViewportStyleOverflow;
 
   nsCompatibility       mCompatibilityMode;
   PRUint16              mImageAnimationMode;
diff --git a/mozilla/layout/base/src/nsPresContext.cpp b/mozilla/layout/base/src/nsPresContext.cpp
index e3626a5629f..e28e6ff61cd 100644
--- a/mozilla/layout/base/src/nsPresContext.cpp
+++ b/mozilla/layout/base/src/nsPresContext.cpp
@@ -140,6 +140,7 @@ static NS_DEFINE_CID(kSelectionImageService, NS_SELECTIONIMAGESERVICE_CID);
 
 nsPresContext::nsPresContext(nsPresContextType aType)
   : mType(aType),
+    mViewportStyleOverflow(NS_STYLE_OVERFLOW_AUTO, NS_STYLE_OVERFLOW_AUTO),
     mCompatibilityMode(eCompatibility_FullStandards),
     mImageAnimationModePref(imgIContainer::kNormalAnimMode),
     mDefaultVariableFont("serif", NS_FONT_STYLE_NORMAL, NS_FONT_VARIANT_NORMAL,
@@ -165,8 +166,6 @@ nsPresContext::nsPresContext(nsPresContextType aType)
   SetBackgroundImageDraw(PR_TRUE);		// always draw the background
   SetBackgroundColorDraw(PR_TRUE);
 
-  mViewportStyleOverflow = NS_STYLE_OVERFLOW_AUTO;
-
   mBackgroundColor = NS_RGB(0xFF, 0xFF, 0xFF);
   
   mUseDocumentColors = PR_TRUE;
diff --git a/mozilla/layout/forms/nsTextControlFrame.cpp b/mozilla/layout/forms/nsTextControlFrame.cpp
index 89c062f027a..3b0243152b8 100644
--- a/mozilla/layout/forms/nsTextControlFrame.cpp
+++ b/mozilla/layout/forms/nsTextControlFrame.cpp
@@ -1637,9 +1637,8 @@ nsTextControlFrame::CreateAnonymousContent(nsPresContext* aPresContext,
     // setting -moz-hidden-unscrollable overflow (NS_STYLE_OVERFLOW_CLIP)
     // doesn't paint the caret for some reason.
     const nsStyleDisplay* disp = GetStyleDisplay();
-    if (disp->mOverflow != NS_STYLE_OVERFLOW_AUTO &&  // this is the default
-        disp->mOverflow != NS_STYLE_OVERFLOW_VISIBLE &&
-        disp->mOverflow != NS_STYLE_OVERFLOW_CLIP) {
+    if (disp->mOverflowX != NS_STYLE_OVERFLOW_VISIBLE &&
+        disp->mOverflowX != NS_STYLE_OVERFLOW_CLIP) {
       rv = divContent->SetAttr(kNameSpaceID_None, nsHTMLAtoms::style,
                                NS_LITERAL_STRING("overflow: inherit;"),
                                PR_FALSE);
@@ -2997,16 +2996,6 @@ nsTextControlFrame::SetInitialChildList(nsPresContext* aPresContext,
   // than descending from the root frame of the frame hierarchy.
   first->AddStateBits(NS_FRAME_REFLOW_ROOT);
 
-//we must turn off scrollbars for singleline text controls
-  if (IsSingleLineTextControl()) 
-  {
-    nsIScrollableFrame *scrollableFrame = nsnull;
-    if (first)
-      first->QueryInterface(NS_GET_IID(nsIScrollableFrame), (void **) &scrollableFrame);
-    if (scrollableFrame)
-      scrollableFrame->SetScrollbarVisibility(aPresContext,PR_FALSE,PR_FALSE);
-  }
-
   //register keylistener
   nsCOMPtr<nsIDOMEventReceiver> erP;
   if (NS_SUCCEEDED(mContent->QueryInterface(NS_GET_IID(nsIDOMEventReceiver), getter_AddRefs(erP))) && erP)
diff --git a/mozilla/layout/generic/nsBlockFrame.cpp b/mozilla/layout/generic/nsBlockFrame.cpp
index da6a7e6f985..79a528fc5b2 100644
--- a/mozilla/layout/generic/nsBlockFrame.cpp
+++ b/mozilla/layout/generic/nsBlockFrame.cpp
@@ -910,7 +910,7 @@ nsBlockFrame::Reflow(nsPresContext*          aPresContext,
   }
 
   if (NS_FRAME_IS_NOT_COMPLETE(state.mReflowStatus)) {
-    if (NS_STYLE_OVERFLOW_CLIP == aReflowState.mStyleDisplay->mOverflow) {
+    if (NS_STYLE_OVERFLOW_CLIP == aReflowState.mStyleDisplay->mOverflowX) {
       state.mReflowStatus = NS_FRAME_COMPLETE;
     }
     else {
@@ -1382,7 +1382,7 @@ nsBlockFrame::ComputeCombinedArea(const nsHTMLReflowState& aReflowState,
   // XXX_perf: This can be done incrementally.  It is currently one of
   // the things that makes incremental reflow O(N^2).
   nsRect area(0, 0, aMetrics.width, aMetrics.height);
-  if (NS_STYLE_OVERFLOW_CLIP != aReflowState.mStyleDisplay->mOverflow) {
+  if (NS_STYLE_OVERFLOW_CLIP != aReflowState.mStyleDisplay->mOverflowX) {
     for (line_iterator line = begin_lines(), line_end = end_lines();
          line != line_end;
          ++line) {
@@ -5326,7 +5326,7 @@ nsBlockFrame::Paint(nsPresContext*      aPresContext,
   // If overflow is hidden then set the clip rect so that children don't
   // leak out of us. Note that because overflow'-clip' only applies to
   // the content area we do this after painting the border and background
-  if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflow) {
+  if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflowX) {
     aRenderingContext.PushState();
     SetOverflowClipRect(aRenderingContext);
   }
@@ -5340,7 +5340,7 @@ nsBlockFrame::Paint(nsPresContext*      aPresContext,
   PaintDecorationsAndChildren(aPresContext, aRenderingContext,
                               aDirtyRect, aWhichLayer, PR_TRUE);
 
-  if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflow)
+  if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflowX)
     aRenderingContext.PopState();
 
 #if 0
diff --git a/mozilla/layout/generic/nsContainerFrame.cpp b/mozilla/layout/generic/nsContainerFrame.cpp
index 8f1005a5549..448c2a1dc21 100644
--- a/mozilla/layout/generic/nsContainerFrame.cpp
+++ b/mozilla/layout/generic/nsContainerFrame.cpp
@@ -650,7 +650,7 @@ SyncFrameViewGeometryDependentProperties(nsPresContext*  aPresContext,
     const nsStyleVisibility* vis = aStyleContext->GetStyleVisibility();
     if ((nsViewVisibility_kShow == aView->GetVisibility()
          && NS_STYLE_VISIBILITY_HIDDEN == vis->mVisible)
-        || (NS_STYLE_OVERFLOW_VISIBLE == display->mOverflow
+        || (NS_STYLE_OVERFLOW_VISIBLE == display->mOverflowX
             && (kidState & NS_FRAME_OUTSIDE_CHILDREN) != 0)) {
       viewHasTransparentContent = PR_TRUE;
     }
@@ -671,7 +671,7 @@ SyncFrameViewGeometryDependentProperties(nsPresContext*  aPresContext,
   //   in the style context...
   PRBool isBlockLevel = display->IsBlockLevel() || (kidState & NS_FRAME_OUT_OF_FLOW);
   PRBool hasClip = display->IsAbsolutelyPositioned() && (display->mClipFlags & NS_STYLE_CLIP_RECT);
-  PRBool hasOverflowClip = isBlockLevel && (display->mOverflow == NS_STYLE_OVERFLOW_CLIP);
+  PRBool hasOverflowClip = isBlockLevel && (display->mOverflowX == NS_STYLE_OVERFLOW_CLIP);
   if (hasClip || hasOverflowClip) {
     nsSize frameSize = aFrame->GetSize();
     nsRect  clipRect;
@@ -922,7 +922,7 @@ nsContainerFrame::FrameNeedsView(nsIFrame* aFrame)
   // block-level, but we can't trust that the style context 'display' value is
   // set correctly
   if ((display->IsBlockLevel() || display->IsFloating()) &&
-      (display->mOverflow == NS_STYLE_OVERFLOW_CLIP)) {
+      (display->mOverflowX == NS_STYLE_OVERFLOW_CLIP)) {
     // XXX Check for the frame being a block frame and only force a view
     // in that case, because adding a view for box frames seems to cause
     // problems for XUL...
diff --git a/mozilla/layout/generic/nsFrame.cpp b/mozilla/layout/generic/nsFrame.cpp
index aac1f82dec9..65927b1be64 100644
--- a/mozilla/layout/generic/nsFrame.cpp
+++ b/mozilla/layout/generic/nsFrame.cpp
@@ -4269,8 +4269,7 @@ nsFrame::ConsiderChildOverflow(nsPresContext* aPresContext,
   const nsStyleDisplay* disp = GetStyleDisplay();
   // check here also for hidden as table frames (table, tr and td) currently 
   // don't wrap their content into a scrollable frame if overflow is specified
-  if (NS_STYLE_OVERFLOW_CLIP != disp->mOverflow &&
-      NS_STYLE_OVERFLOW_HIDDEN != disp->mOverflow) {
+  if (!disp->IsTableClip()) {
     nsRect* overflowArea = aChildFrame->GetOverflowAreaProperty();
     if (overflowArea) {
       nsRect childOverflow(*overflowArea);
diff --git a/mozilla/layout/generic/nsFrameFrame.cpp b/mozilla/layout/generic/nsFrameFrame.cpp
index 63f215c82b8..449917e136e 100644
--- a/mozilla/layout/generic/nsFrameFrame.cpp
+++ b/mozilla/layout/generic/nsFrameFrame.cpp
@@ -617,6 +617,20 @@ nsSubDocumentFrame::GetDocShell(nsIDocShell **aDocShell)
   return mFrameLoader->GetDocShell(aDocShell);
 }
 
+inline PRInt32 ConvertOverflow(PRUint8 aOverflow)
+{
+  switch (aOverflow) {
+    case NS_STYLE_OVERFLOW_VISIBLE:
+    case NS_STYLE_OVERFLOW_AUTO:
+      return nsIScrollable::Scrollbar_Auto;
+    case NS_STYLE_OVERFLOW_HIDDEN:
+    case NS_STYLE_OVERFLOW_CLIP:
+      return nsIScrollable::Scrollbar_Never;
+    case NS_STYLE_OVERFLOW_SCROLL:
+      return nsIScrollable::Scrollbar_Always;
+  }
+}
+
 nsresult
 nsSubDocumentFrame::ShowDocShell()
 {
@@ -645,33 +659,11 @@ nsSubDocumentFrame::ShowDocShell()
   nsCOMPtr<nsIScrollable> sc(do_QueryInterface(docShell));
 
   if (sc) {
-    PRInt32 scrolling = GetStyleDisplay()->mOverflow;
-    PRInt32 scrollX, scrollY;
-    switch (scrolling) {
-      case NS_STYLE_OVERFLOW_CLIP:
-        scrollX = NS_STYLE_OVERFLOW_HIDDEN;
-        scrollY = NS_STYLE_OVERFLOW_HIDDEN;
-        break;
-      case NS_STYLE_OVERFLOW_SCROLLBARS_HORIZONTAL:
-        scrollX = NS_STYLE_OVERFLOW_SCROLL;
-        scrollY = NS_STYLE_OVERFLOW_HIDDEN;
-        break;
-      case NS_STYLE_OVERFLOW_SCROLLBARS_VERTICAL:
-        scrollX = NS_STYLE_OVERFLOW_HIDDEN;
-        scrollY = NS_STYLE_OVERFLOW_SCROLL;
-        break;
-      case NS_STYLE_OVERFLOW_VISIBLE:
-        scrollX = scrollY = NS_STYLE_OVERFLOW_AUTO;
-        break;
-      default:
-        scrollX = scrollY = scrolling;
-        break;
-    }
-
-    sc->SetDefaultScrollbarPreferences(nsIScrollable::ScrollOrientation_Y,
-                                       scrollX);
+    const nsStyleDisplay *disp = GetStyleDisplay();
     sc->SetDefaultScrollbarPreferences(nsIScrollable::ScrollOrientation_X,
-                                       scrollY);
+                                       ConvertOverflow(disp->mOverflowX));
+    sc->SetDefaultScrollbarPreferences(nsIScrollable::ScrollOrientation_Y,
+                                       ConvertOverflow(disp->mOverflowY));
   }
 
   PRInt32 itemType = nsIDocShellTreeItem::typeContent;
diff --git a/mozilla/layout/generic/nsGfxScrollFrame.cpp b/mozilla/layout/generic/nsGfxScrollFrame.cpp
index c33f6f3272c..acc5d19579a 100644
--- a/mozilla/layout/generic/nsGfxScrollFrame.cpp
+++ b/mozilla/layout/generic/nsGfxScrollFrame.cpp
@@ -45,6 +45,7 @@
 #include "nsIServiceManager.h"
 #include "nsIView.h"
 #include "nsIScrollableView.h"
+#include "nsIScrollable.h"
 #include "nsIViewManager.h"
 #include "nsHTMLContainerFrame.h"
 #include "nsWidgetsCID.h"
@@ -127,20 +128,6 @@ nsHTMLScrollFrame::ScrollTo(nsPresContext* aContext, nscoord aX, nscoord aY, PRU
    return s->ScrollTo(aX, aY, aFlags);
 }
 
-/**
- * Query whether scroll bars should be displayed all the time, never or
- * only when necessary.
- * @return current scrollbar selection
- * XXX roc only 'Auto' is really tested for. This API should be simplified or
- * eliminated.
- */
-NS_IMETHODIMP
-nsHTMLScrollFrame::GetScrollPreference(nsPresContext* aPresContext, nsScrollPref* aScrollPreference) const
-{
-  *aScrollPreference = mInner.GetScrollPreference();
-  return NS_OK;
-}
-
 nsGfxScrollFrameInner::ScrollbarStyles
 nsHTMLScrollFrame::GetScrollbarStyles() const {
   return mInner.GetScrollbarStylesFromFrame();
@@ -181,16 +168,6 @@ nsMargin nsHTMLScrollFrame::GetDesiredScrollbarSizes(nsBoxLayoutState* aState) {
   return result;
 }
 
-NS_IMETHODIMP
-nsHTMLScrollFrame::SetScrollbarVisibility(nsPresContext* aPresContext,
-                                    PRBool aVerticalVisible,
-                                    PRBool aHorizontalVisible)
-{
-  mInner.mNeverHasVerticalScrollbar = !aVerticalVisible;
-  mInner.mNeverHasHorizontalScrollbar = !aHorizontalVisible;
-  return NS_OK;
-}
-
 NS_IMETHODIMP
 nsHTMLScrollFrame::GetScrollbarBox(PRBool aVertical, nsIBox** aResult)
 {
@@ -667,20 +644,6 @@ nsXULScrollFrame::ScrollTo(nsPresContext* aContext, nscoord aX, nscoord aY, PRUi
    return s->ScrollTo(aX, aY, aFlags);
 }
 
-/**
- * Query whether scroll bars should be displayed all the time, never or
- * only when necessary.
- * @return current scrollbar selection
- * XXX roc only 'Auto' is really tested for. This API should be simplified or
- * eliminated.
- */
-NS_IMETHODIMP
-nsXULScrollFrame::GetScrollPreference(nsPresContext* aPresContext, nsScrollPref* aScrollPreference) const
-{
-  *aScrollPreference = mInner.GetScrollPreference();
-  return NS_OK;
-}
-
 nsGfxScrollFrameInner::ScrollbarStyles
 nsXULScrollFrame::GetScrollbarStyles() const {
   return mInner.GetScrollbarStylesFromFrame();
@@ -721,16 +684,6 @@ nsMargin nsXULScrollFrame::GetDesiredScrollbarSizes(nsBoxLayoutState* aState) {
   return result;
 }
 
-NS_IMETHODIMP
-nsXULScrollFrame::SetScrollbarVisibility(nsPresContext* aPresContext,
-                                    PRBool aVerticalVisible,
-                                    PRBool aHorizontalVisible)
-{
-  mInner.mNeverHasVerticalScrollbar = !aVerticalVisible;
-  mInner.mNeverHasHorizontalScrollbar = !aHorizontalVisible;
-  return NS_OK;
-}
-
 NS_IMETHODIMP
 nsXULScrollFrame::GetScrollbarBox(PRBool aVertical, nsIBox** aResult)
 {
@@ -1164,8 +1117,6 @@ nsGfxScrollFrameInner::nsGfxScrollFrameInner(nsBoxFrame* aOuter)
     mOuter(aOuter),
     mMaxElementWidth(0),
     mLastDir(-1),
-    mNeverHasVerticalScrollbar(PR_FALSE),
-    mNeverHasHorizontalScrollbar(PR_FALSE),
     mHasVerticalScrollbar(PR_FALSE), 
     mHasHorizontalScrollbar(PR_FALSE),
     mFirstPass(PR_FALSE),
@@ -1188,62 +1139,54 @@ NS_IMETHODIMP_(nsrefcnt) nsGfxScrollFrameInner::Release(void)
 
 NS_IMPL_QUERY_INTERFACE1(nsGfxScrollFrameInner, nsIScrollPositionListener)
 
+static void HandleScrollPref(nsIScrollable *aScrollable, PRInt32 aOrientation,
+                             PRUint8& aValue)
+{
+  PRInt32 pref;
+  aScrollable->GetDefaultScrollbarPreferences(aOrientation, &pref);
+  switch (pref) {
+    case nsIScrollable::Scrollbar_Auto:
+      // leave |aValue| untouched
+      break;
+    case nsIScrollable::Scrollbar_Never:
+      aValue = NS_STYLE_OVERFLOW_HIDDEN;
+      break;
+    case nsIScrollable::Scrollbar_Always:
+      aValue = NS_STYLE_OVERFLOW_SCROLL;
+      break;
+  }
+}
+
 nsGfxScrollFrameInner::ScrollbarStyles
 nsGfxScrollFrameInner::GetScrollbarStylesFromFrame() const
 {
-  PRUint8 overflow;
+  ScrollbarStyles result;
   nsIFrame* parent = mOuter->GetParent();
   if (parent && parent->GetType() == nsLayoutAtoms::viewportFrame &&
       // Make sure we're actually the root scrollframe
       parent->GetFirstChild(nsnull) ==
         NS_STATIC_CAST(const nsIFrame*, mOuter)) {
-    overflow = mOuter->GetPresContext()->GetViewportOverflowOverride();
+    nsPresContext *presContext = mOuter->GetPresContext();
+    result = presContext->GetViewportOverflowOverride();
+
+    nsCOMPtr<nsISupports> container = presContext->GetContainer();
+    nsCOMPtr<nsIScrollable> scrollable = do_QueryInterface(container);
+    HandleScrollPref(scrollable, nsIScrollable::ScrollOrientation_X,
+                     result.mHorizontal);
+    HandleScrollPref(scrollable, nsIScrollable::ScrollOrientation_Y,
+                     result.mVertical);
   } else {
-    overflow = mOuter->GetStyleDisplay()->mOverflow;
+    const nsStyleDisplay *disp = mOuter->GetStyleDisplay();
+    result.mHorizontal = disp->mOverflowX;
+    result.mVertical = disp->mOverflowY;
   }
 
-  switch (overflow) {
-  case NS_STYLE_OVERFLOW_SCROLL:
-  case NS_STYLE_OVERFLOW_HIDDEN:
-  case NS_STYLE_OVERFLOW_VISIBLE: // should never happen
-  case NS_STYLE_OVERFLOW_AUTO:
-    return ScrollbarStyles(overflow, overflow);
-  case NS_STYLE_OVERFLOW_CLIP:
-    // This isn't quite right (although the value is deprecated and not
-    // very important). The scrollframe will still be scrollable using
-    // keys.  This can happen when HTML or BODY has propagated the style
-    // to the viewport.  (In other cases, there will be no scrollframe.)
-    return ScrollbarStyles(NS_STYLE_OVERFLOW_HIDDEN, NS_STYLE_OVERFLOW_HIDDEN);
-  case NS_STYLE_OVERFLOW_SCROLLBARS_VERTICAL:
-    return ScrollbarStyles(NS_STYLE_OVERFLOW_HIDDEN, NS_STYLE_OVERFLOW_SCROLL);
-  case NS_STYLE_OVERFLOW_SCROLLBARS_HORIZONTAL:
-    return ScrollbarStyles(NS_STYLE_OVERFLOW_SCROLL, NS_STYLE_OVERFLOW_HIDDEN);
-  default:
-    NS_NOTREACHED("invalid overflow value");
-    return ScrollbarStyles(NS_STYLE_OVERFLOW_HIDDEN, NS_STYLE_OVERFLOW_HIDDEN);
-  }
-}
-
-nsIScrollableFrame::nsScrollPref
-nsGfxScrollFrameInner::GetScrollPreference() const
-{
-  nsCOMPtr<nsIScrollableFrame> scrollable =
-    do_QueryInterface(NS_STATIC_CAST(nsIFrame*, mOuter));
-  ScrollbarStyles styles = scrollable->GetScrollbarStyles();
-
-  if (styles.mHorizontal == NS_STYLE_OVERFLOW_SCROLL &&
-      styles.mVertical == NS_STYLE_OVERFLOW_SCROLL) {
-    return nsIScrollableFrame::AlwaysScroll;
-  } else if (styles.mHorizontal == NS_STYLE_OVERFLOW_SCROLL) {
-    return nsIScrollableFrame::AlwaysScrollHorizontal;
-  } else if (styles.mVertical == NS_STYLE_OVERFLOW_SCROLL) {
-    return nsIScrollableFrame::AlwaysScrollVertical;
-  } else if (styles.mHorizontal == NS_STYLE_OVERFLOW_AUTO ||
-             styles.mVertical == NS_STYLE_OVERFLOW_AUTO) {
-    return nsIScrollableFrame::Auto;
-  } else {
-    return nsIScrollableFrame::NeverScroll;
-  }
+  NS_ASSERTION(result.mHorizontal != NS_STYLE_OVERFLOW_VISIBLE &&
+               result.mHorizontal != NS_STYLE_OVERFLOW_CLIP &&
+               result.mVertical != NS_STYLE_OVERFLOW_VISIBLE &&
+               result.mVertical != NS_STYLE_OVERFLOW_CLIP,
+               "scrollbars should not have been created");
+  return result;
 }
 
 void
@@ -1314,45 +1257,31 @@ nsGfxScrollFrameInner::CreateAnonymousContent(nsISupportsArray& aAnonymousChildr
     // allow scrollbars if this is the child of the viewport, because
     // we must be the scrollbars for the print preview window
     if (!parent || parent->GetType() != nsLayoutAtoms::viewportFrame) {
-      mNeverHasVerticalScrollbar = mNeverHasHorizontalScrollbar = PR_TRUE;
+      // If we just return early here, we'll never create content or
+      // frames an |mHScrollbarBox| and |mVScrollbarBox| will always be
+      // null.
       return;
     }
   }
 
-  nsIPresShell *shell = presContext->GetPresShell();
-  nsIDocument *document = nsnull;
-  if (shell)
-    document = shell->GetDocument();
+  nsIScrollableFrame *scrollable;
+  CallQueryInterface(mOuter, &scrollable);
 
-  // The anonymous <div> used by <inputs> never gets scrollbars.
-  nsCOMPtr<nsITextControlFrame> textFrame(do_QueryInterface(parent));
-  if (textFrame) {
-    // Make sure we are not a text area.
-    nsCOMPtr<nsIDOMHTMLTextAreaElement> textAreaElement(do_QueryInterface(parent->GetContent()));
-    if (!textAreaElement) {
-      mNeverHasVerticalScrollbar = mNeverHasHorizontalScrollbar = PR_TRUE;
-      return;
-    }
-  }
-
-  // create horizontal scrollbar
-  if (!document) {
+  ScrollbarStyles styles = scrollable->GetScrollbarStyles();
+  PRBool canHaveHorizontal = styles.mHorizontal != NS_STYLE_OVERFLOW_HIDDEN;
+  PRBool canHaveVertical = styles.mVertical != NS_STYLE_OVERFLOW_HIDDEN;
+  if (!canHaveHorizontal && !canHaveVertical)
+    // Nothing to do.
     return;
-  }
-
-  nsNodeInfoManager *nodeInfoManager = document->NodeInfoManager();
 
+  nsNodeInfoManager *nodeInfoManager =
+    presContext->GetDocument()->NodeInfoManager();
   nsCOMPtr<nsINodeInfo> nodeInfo;
   nodeInfoManager->GetNodeInfo(nsXULAtoms::scrollbar, nsnull,
                                kNameSpaceID_XUL, getter_AddRefs(nodeInfo));
 
   nsCOMPtr<nsIContent> content;
 
-  nsCOMPtr<nsIScrollableFrame> scrollable =
-    do_QueryInterface(NS_STATIC_CAST(nsIFrame*, mOuter));
-  ScrollbarStyles styles = scrollable->GetScrollbarStyles();
-  PRBool canHaveHorizontal = styles.mHorizontal == NS_STYLE_OVERFLOW_AUTO
-    || styles.mHorizontal == NS_STYLE_OVERFLOW_SCROLL;
   if (canHaveHorizontal) {
     NS_NewElement(getter_AddRefs(content), kNameSpaceID_XUL, nodeInfo);
     content->SetAttr(kNameSpaceID_None, nsXULAtoms::orient,
@@ -1360,8 +1289,6 @@ nsGfxScrollFrameInner::CreateAnonymousContent(nsISupportsArray& aAnonymousChildr
     aAnonymousChildren.AppendElement(content);
   }
 
-  PRBool canHaveVertical = styles.mVertical == NS_STYLE_OVERFLOW_AUTO
-    || styles.mVertical == NS_STYLE_OVERFLOW_SCROLL;
   if (canHaveVertical) {
     NS_NewElement(getter_AddRefs(content), kNameSpaceID_XUL, nodeInfo);
     content->SetAttr(kNameSpaceID_None, nsXULAtoms::orient,
@@ -1617,7 +1544,7 @@ PRBool
 nsGfxScrollFrameInner::AddRemoveScrollbar(nsBoxLayoutState& aState, nsRect& aScrollAreaSize, PRBool aOnTop, PRBool aHorizontal, PRBool aAdd)
 {
   if (aHorizontal) {
-     if (mNeverHasHorizontalScrollbar || !mHScrollbarBox)
+     if (!mHScrollbarBox)
        return PR_FALSE;
 
      nsSize hSize;
@@ -1634,7 +1561,7 @@ nsGfxScrollFrameInner::AddRemoveScrollbar(nsBoxLayoutState& aState, nsRect& aScr
 
      return fit;
   } else {
-     if (mNeverHasVerticalScrollbar || !mVScrollbarBox)
+     if (!mVScrollbarBox)
        return PR_FALSE;
 
      nsSize vSize;
@@ -1807,8 +1734,8 @@ nsGfxScrollFrameInner::Layout(nsBoxLayoutState& aState)
    (if we're the viewport and we added or removed a scrollbar).
    **************/
 
-  nsCOMPtr<nsIScrollableFrame> scrollableFrame =
-    do_QueryInterface(NS_STATIC_CAST(nsIFrame*, mOuter));
+  nsIScrollableFrame *scrollableFrame;
+  CallQueryInterface(mOuter, &scrollableFrame);
   ScrollbarStyles styles = scrollableFrame->GetScrollbarStyles();
 
   // Look at our style do we always have vertical or horizontal scrollbars?
diff --git a/mozilla/layout/generic/nsGfxScrollFrame.h b/mozilla/layout/generic/nsGfxScrollFrame.h
index 0faf48ee878..2333ead6481 100644
--- a/mozilla/layout/generic/nsGfxScrollFrame.h
+++ b/mozilla/layout/generic/nsGfxScrollFrame.h
@@ -63,8 +63,6 @@ public:
   typedef nsIScrollableFrame::ScrollbarStyles ScrollbarStyles;
   ScrollbarStyles GetScrollbarStylesFromFrame() const;
 
-  nsIScrollableFrame::nsScrollPref GetScrollPreference() const;
-
   // If a child frame was added or removed on the scrollframe,
   // reload our child frame list.
   // We need this if a scrollbar frame is recreated.
@@ -246,18 +244,12 @@ public:
   NS_IMETHOD GetScrollPosition(nsPresContext* aContext, nscoord &aX, nscoord& aY) const;
   NS_IMETHOD ScrollTo(nsPresContext* aContext, nscoord aX, nscoord aY, PRUint32 aFlags);
 
-  NS_IMETHOD SetScrollbarVisibility(nsPresContext* aPresContext,
-                                    PRBool aVerticalVisible,
-                                    PRBool aHorizontalVisible);
-
   NS_IMETHOD GetScrollbarBox(PRBool aVertical, nsIBox** aResult);
 
   NS_IMETHOD CurPosAttributeChanged(nsPresContext* aPresContext,
                                     nsIContent* aChild,
                                     PRInt32 aModType);
 
-  NS_IMETHOD  GetScrollPreference(nsPresContext* aPresContext, nsScrollPref* aScrollPreference) const;
-
   virtual void ScrollToRestoredPosition() {
     mInner.ScrollToRestoredPosition();
   }
@@ -377,18 +369,12 @@ public:
   NS_IMETHOD GetScrollPosition(nsPresContext* aContext, nscoord &aX, nscoord& aY) const;
   NS_IMETHOD ScrollTo(nsPresContext* aContext, nscoord aX, nscoord aY, PRUint32 aFlags);
 
-  NS_IMETHOD SetScrollbarVisibility(nsPresContext* aPresContext,
-                                    PRBool aVerticalVisible,
-                                    PRBool aHorizontalVisible);
-
   NS_IMETHOD GetScrollbarBox(PRBool aVertical, nsIBox** aResult);
 
   NS_IMETHOD CurPosAttributeChanged(nsPresContext* aPresContext,
                                     nsIContent* aChild,
                                     PRInt32 aModType);
 
-  NS_IMETHOD  GetScrollPreference(nsPresContext* aPresContext, nsScrollPref* aScrollPreference) const;
-
   virtual void ScrollToRestoredPosition() {
     mInner.ScrollToRestoredPosition();
   }
diff --git a/mozilla/layout/generic/nsIScrollableFrame.h b/mozilla/layout/generic/nsIScrollableFrame.h
index 270a5445a14..be0db689a87 100644
--- a/mozilla/layout/generic/nsIScrollableFrame.h
+++ b/mozilla/layout/generic/nsIScrollableFrame.h
@@ -42,10 +42,10 @@
 #include "nsCoord.h"
 #include "nsIViewManager.h"
 #include "nsIScrollableViewProvider.h"
+#include "nsPresContext.h"
 
 class nsIFrame;
 class nsIBox;
-class nsPresContext;
 class nsBoxLayoutState;
 
 // IID for the nsIScrollableFrame interface
@@ -56,14 +56,6 @@ class nsBoxLayoutState;
 class nsIScrollableFrame : public nsIScrollableViewProvider {
 public:
 
-  enum nsScrollPref {
-    Auto = 0,
-    NeverScroll,
-    AlwaysScroll,
-    AlwaysScrollVertical,
-    AlwaysScrollHorizontal
-  };
-
   NS_DEFINE_STATIC_IID_ACCESSOR(NS_ISCROLLABLE_FRAME_IID)
 
   /**
@@ -73,13 +65,7 @@ public:
   NS_IMETHOD GetScrolledFrame(nsPresContext* aPresContext,
                               nsIFrame *&aScrolledFrame) const = 0;
 
-  struct ScrollbarStyles {
-    // one of NS_STYLE_OVERFLOW_SCROLL, NS_STYLE_OVERFLOW_HIDDEN,
-    // NS_STYLE_OVERFLOW_VISIBLE, NS_STYLE_OVERFLOW_AUTO
-    PRInt32 mHorizontal;
-    PRInt32 mVertical;
-    ScrollbarStyles(PRInt32 h, PRInt32 v) : mHorizontal(h), mVertical(v) {}
-  };
+  typedef nsPresContext::ScrollbarStyles ScrollbarStyles;
 
   virtual ScrollbarStyles GetScrollbarStyles() const = 0;
 
@@ -95,13 +81,6 @@ public:
    */
   virtual nsMargin GetDesiredScrollbarSizes(nsBoxLayoutState* aState) = 0;
 
-  /**
-   * Query whether scroll bars should be displayed all the time, never or
-   * only when necessary.
-   * @return current scrollbar selection
-   */
-  NS_IMETHOD  GetScrollPreference(nsPresContext* aPresContext, nsScrollPref* aScrollPreference) const = 0;
-
   /**
    * Get the position of the scrolled view.
    */
@@ -120,15 +99,6 @@ public:
 
   NS_IMETHOD GetScrollableView(nsPresContext* aContext, nsIScrollableView** aResult)=0;
 
-
-  /**
-   * Set information about whether the vertical and horizontal scrollbars
-   * are currently visible
-   */
-  NS_IMETHOD SetScrollbarVisibility(nsPresContext* aPresContext,
-                                    PRBool aVerticalVisible,
-                                    PRBool aHorizontalVisible) = 0;
-
   NS_IMETHOD GetScrollbarBox(PRBool aVertical, nsIBox** aResult) = 0;
 
   NS_IMETHOD CurPosAttributeChanged(nsPresContext* aPresContext,
diff --git a/mozilla/layout/html/base/src/nsBlockFrame.cpp b/mozilla/layout/html/base/src/nsBlockFrame.cpp
index da6a7e6f985..79a528fc5b2 100644
--- a/mozilla/layout/html/base/src/nsBlockFrame.cpp
+++ b/mozilla/layout/html/base/src/nsBlockFrame.cpp
@@ -910,7 +910,7 @@ nsBlockFrame::Reflow(nsPresContext*          aPresContext,
   }
 
   if (NS_FRAME_IS_NOT_COMPLETE(state.mReflowStatus)) {
-    if (NS_STYLE_OVERFLOW_CLIP == aReflowState.mStyleDisplay->mOverflow) {
+    if (NS_STYLE_OVERFLOW_CLIP == aReflowState.mStyleDisplay->mOverflowX) {
       state.mReflowStatus = NS_FRAME_COMPLETE;
     }
     else {
@@ -1382,7 +1382,7 @@ nsBlockFrame::ComputeCombinedArea(const nsHTMLReflowState& aReflowState,
   // XXX_perf: This can be done incrementally.  It is currently one of
   // the things that makes incremental reflow O(N^2).
   nsRect area(0, 0, aMetrics.width, aMetrics.height);
-  if (NS_STYLE_OVERFLOW_CLIP != aReflowState.mStyleDisplay->mOverflow) {
+  if (NS_STYLE_OVERFLOW_CLIP != aReflowState.mStyleDisplay->mOverflowX) {
     for (line_iterator line = begin_lines(), line_end = end_lines();
          line != line_end;
          ++line) {
@@ -5326,7 +5326,7 @@ nsBlockFrame::Paint(nsPresContext*      aPresContext,
   // If overflow is hidden then set the clip rect so that children don't
   // leak out of us. Note that because overflow'-clip' only applies to
   // the content area we do this after painting the border and background
-  if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflow) {
+  if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflowX) {
     aRenderingContext.PushState();
     SetOverflowClipRect(aRenderingContext);
   }
@@ -5340,7 +5340,7 @@ nsBlockFrame::Paint(nsPresContext*      aPresContext,
   PaintDecorationsAndChildren(aPresContext, aRenderingContext,
                               aDirtyRect, aWhichLayer, PR_TRUE);
 
-  if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflow)
+  if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflowX)
     aRenderingContext.PopState();
 
 #if 0
diff --git a/mozilla/layout/html/base/src/nsContainerFrame.cpp b/mozilla/layout/html/base/src/nsContainerFrame.cpp
index 8f1005a5549..448c2a1dc21 100644
--- a/mozilla/layout/html/base/src/nsContainerFrame.cpp
+++ b/mozilla/layout/html/base/src/nsContainerFrame.cpp
@@ -650,7 +650,7 @@ SyncFrameViewGeometryDependentProperties(nsPresContext*  aPresContext,
     const nsStyleVisibility* vis = aStyleContext->GetStyleVisibility();
     if ((nsViewVisibility_kShow == aView->GetVisibility()
          && NS_STYLE_VISIBILITY_HIDDEN == vis->mVisible)
-        || (NS_STYLE_OVERFLOW_VISIBLE == display->mOverflow
+        || (NS_STYLE_OVERFLOW_VISIBLE == display->mOverflowX
             && (kidState & NS_FRAME_OUTSIDE_CHILDREN) != 0)) {
       viewHasTransparentContent = PR_TRUE;
     }
@@ -671,7 +671,7 @@ SyncFrameViewGeometryDependentProperties(nsPresContext*  aPresContext,
   //   in the style context...
   PRBool isBlockLevel = display->IsBlockLevel() || (kidState & NS_FRAME_OUT_OF_FLOW);
   PRBool hasClip = display->IsAbsolutelyPositioned() && (display->mClipFlags & NS_STYLE_CLIP_RECT);
-  PRBool hasOverflowClip = isBlockLevel && (display->mOverflow == NS_STYLE_OVERFLOW_CLIP);
+  PRBool hasOverflowClip = isBlockLevel && (display->mOverflowX == NS_STYLE_OVERFLOW_CLIP);
   if (hasClip || hasOverflowClip) {
     nsSize frameSize = aFrame->GetSize();
     nsRect  clipRect;
@@ -922,7 +922,7 @@ nsContainerFrame::FrameNeedsView(nsIFrame* aFrame)
   // block-level, but we can't trust that the style context 'display' value is
   // set correctly
   if ((display->IsBlockLevel() || display->IsFloating()) &&
-      (display->mOverflow == NS_STYLE_OVERFLOW_CLIP)) {
+      (display->mOverflowX == NS_STYLE_OVERFLOW_CLIP)) {
     // XXX Check for the frame being a block frame and only force a view
     // in that case, because adding a view for box frames seems to cause
     // problems for XUL...
diff --git a/mozilla/layout/html/base/src/nsFrame.cpp b/mozilla/layout/html/base/src/nsFrame.cpp
index aac1f82dec9..65927b1be64 100644
--- a/mozilla/layout/html/base/src/nsFrame.cpp
+++ b/mozilla/layout/html/base/src/nsFrame.cpp
@@ -4269,8 +4269,7 @@ nsFrame::ConsiderChildOverflow(nsPresContext* aPresContext,
   const nsStyleDisplay* disp = GetStyleDisplay();
   // check here also for hidden as table frames (table, tr and td) currently 
   // don't wrap their content into a scrollable frame if overflow is specified
-  if (NS_STYLE_OVERFLOW_CLIP != disp->mOverflow &&
-      NS_STYLE_OVERFLOW_HIDDEN != disp->mOverflow) {
+  if (!disp->IsTableClip()) {
     nsRect* overflowArea = aChildFrame->GetOverflowAreaProperty();
     if (overflowArea) {
       nsRect childOverflow(*overflowArea);
diff --git a/mozilla/layout/html/base/src/nsGfxScrollFrame.cpp b/mozilla/layout/html/base/src/nsGfxScrollFrame.cpp
index c33f6f3272c..acc5d19579a 100644
--- a/mozilla/layout/html/base/src/nsGfxScrollFrame.cpp
+++ b/mozilla/layout/html/base/src/nsGfxScrollFrame.cpp
@@ -45,6 +45,7 @@
 #include "nsIServiceManager.h"
 #include "nsIView.h"
 #include "nsIScrollableView.h"
+#include "nsIScrollable.h"
 #include "nsIViewManager.h"
 #include "nsHTMLContainerFrame.h"
 #include "nsWidgetsCID.h"
@@ -127,20 +128,6 @@ nsHTMLScrollFrame::ScrollTo(nsPresContext* aContext, nscoord aX, nscoord aY, PRU
    return s->ScrollTo(aX, aY, aFlags);
 }
 
-/**
- * Query whether scroll bars should be displayed all the time, never or
- * only when necessary.
- * @return current scrollbar selection
- * XXX roc only 'Auto' is really tested for. This API should be simplified or
- * eliminated.
- */
-NS_IMETHODIMP
-nsHTMLScrollFrame::GetScrollPreference(nsPresContext* aPresContext, nsScrollPref* aScrollPreference) const
-{
-  *aScrollPreference = mInner.GetScrollPreference();
-  return NS_OK;
-}
-
 nsGfxScrollFrameInner::ScrollbarStyles
 nsHTMLScrollFrame::GetScrollbarStyles() const {
   return mInner.GetScrollbarStylesFromFrame();
@@ -181,16 +168,6 @@ nsMargin nsHTMLScrollFrame::GetDesiredScrollbarSizes(nsBoxLayoutState* aState) {
   return result;
 }
 
-NS_IMETHODIMP
-nsHTMLScrollFrame::SetScrollbarVisibility(nsPresContext* aPresContext,
-                                    PRBool aVerticalVisible,
-                                    PRBool aHorizontalVisible)
-{
-  mInner.mNeverHasVerticalScrollbar = !aVerticalVisible;
-  mInner.mNeverHasHorizontalScrollbar = !aHorizontalVisible;
-  return NS_OK;
-}
-
 NS_IMETHODIMP
 nsHTMLScrollFrame::GetScrollbarBox(PRBool aVertical, nsIBox** aResult)
 {
@@ -667,20 +644,6 @@ nsXULScrollFrame::ScrollTo(nsPresContext* aContext, nscoord aX, nscoord aY, PRUi
    return s->ScrollTo(aX, aY, aFlags);
 }
 
-/**
- * Query whether scroll bars should be displayed all the time, never or
- * only when necessary.
- * @return current scrollbar selection
- * XXX roc only 'Auto' is really tested for. This API should be simplified or
- * eliminated.
- */
-NS_IMETHODIMP
-nsXULScrollFrame::GetScrollPreference(nsPresContext* aPresContext, nsScrollPref* aScrollPreference) const
-{
-  *aScrollPreference = mInner.GetScrollPreference();
-  return NS_OK;
-}
-
 nsGfxScrollFrameInner::ScrollbarStyles
 nsXULScrollFrame::GetScrollbarStyles() const {
   return mInner.GetScrollbarStylesFromFrame();
@@ -721,16 +684,6 @@ nsMargin nsXULScrollFrame::GetDesiredScrollbarSizes(nsBoxLayoutState* aState) {
   return result;
 }
 
-NS_IMETHODIMP
-nsXULScrollFrame::SetScrollbarVisibility(nsPresContext* aPresContext,
-                                    PRBool aVerticalVisible,
-                                    PRBool aHorizontalVisible)
-{
-  mInner.mNeverHasVerticalScrollbar = !aVerticalVisible;
-  mInner.mNeverHasHorizontalScrollbar = !aHorizontalVisible;
-  return NS_OK;
-}
-
 NS_IMETHODIMP
 nsXULScrollFrame::GetScrollbarBox(PRBool aVertical, nsIBox** aResult)
 {
@@ -1164,8 +1117,6 @@ nsGfxScrollFrameInner::nsGfxScrollFrameInner(nsBoxFrame* aOuter)
     mOuter(aOuter),
     mMaxElementWidth(0),
     mLastDir(-1),
-    mNeverHasVerticalScrollbar(PR_FALSE),
-    mNeverHasHorizontalScrollbar(PR_FALSE),
     mHasVerticalScrollbar(PR_FALSE), 
     mHasHorizontalScrollbar(PR_FALSE),
     mFirstPass(PR_FALSE),
@@ -1188,62 +1139,54 @@ NS_IMETHODIMP_(nsrefcnt) nsGfxScrollFrameInner::Release(void)
 
 NS_IMPL_QUERY_INTERFACE1(nsGfxScrollFrameInner, nsIScrollPositionListener)
 
+static void HandleScrollPref(nsIScrollable *aScrollable, PRInt32 aOrientation,
+                             PRUint8& aValue)
+{
+  PRInt32 pref;
+  aScrollable->GetDefaultScrollbarPreferences(aOrientation, &pref);
+  switch (pref) {
+    case nsIScrollable::Scrollbar_Auto:
+      // leave |aValue| untouched
+      break;
+    case nsIScrollable::Scrollbar_Never:
+      aValue = NS_STYLE_OVERFLOW_HIDDEN;
+      break;
+    case nsIScrollable::Scrollbar_Always:
+      aValue = NS_STYLE_OVERFLOW_SCROLL;
+      break;
+  }
+}
+
 nsGfxScrollFrameInner::ScrollbarStyles
 nsGfxScrollFrameInner::GetScrollbarStylesFromFrame() const
 {
-  PRUint8 overflow;
+  ScrollbarStyles result;
   nsIFrame* parent = mOuter->GetParent();
   if (parent && parent->GetType() == nsLayoutAtoms::viewportFrame &&
       // Make sure we're actually the root scrollframe
       parent->GetFirstChild(nsnull) ==
         NS_STATIC_CAST(const nsIFrame*, mOuter)) {
-    overflow = mOuter->GetPresContext()->GetViewportOverflowOverride();
+    nsPresContext *presContext = mOuter->GetPresContext();
+    result = presContext->GetViewportOverflowOverride();
+
+    nsCOMPtr<nsISupports> container = presContext->GetContainer();
+    nsCOMPtr<nsIScrollable> scrollable = do_QueryInterface(container);
+    HandleScrollPref(scrollable, nsIScrollable::ScrollOrientation_X,
+                     result.mHorizontal);
+    HandleScrollPref(scrollable, nsIScrollable::ScrollOrientation_Y,
+                     result.mVertical);
   } else {
-    overflow = mOuter->GetStyleDisplay()->mOverflow;
+    const nsStyleDisplay *disp = mOuter->GetStyleDisplay();
+    result.mHorizontal = disp->mOverflowX;
+    result.mVertical = disp->mOverflowY;
   }
 
-  switch (overflow) {
-  case NS_STYLE_OVERFLOW_SCROLL:
-  case NS_STYLE_OVERFLOW_HIDDEN:
-  case NS_STYLE_OVERFLOW_VISIBLE: // should never happen
-  case NS_STYLE_OVERFLOW_AUTO:
-    return ScrollbarStyles(overflow, overflow);
-  case NS_STYLE_OVERFLOW_CLIP:
-    // This isn't quite right (although the value is deprecated and not
-    // very important). The scrollframe will still be scrollable using
-    // keys.  This can happen when HTML or BODY has propagated the style
-    // to the viewport.  (In other cases, there will be no scrollframe.)
-    return ScrollbarStyles(NS_STYLE_OVERFLOW_HIDDEN, NS_STYLE_OVERFLOW_HIDDEN);
-  case NS_STYLE_OVERFLOW_SCROLLBARS_VERTICAL:
-    return ScrollbarStyles(NS_STYLE_OVERFLOW_HIDDEN, NS_STYLE_OVERFLOW_SCROLL);
-  case NS_STYLE_OVERFLOW_SCROLLBARS_HORIZONTAL:
-    return ScrollbarStyles(NS_STYLE_OVERFLOW_SCROLL, NS_STYLE_OVERFLOW_HIDDEN);
-  default:
-    NS_NOTREACHED("invalid overflow value");
-    return ScrollbarStyles(NS_STYLE_OVERFLOW_HIDDEN, NS_STYLE_OVERFLOW_HIDDEN);
-  }
-}
-
-nsIScrollableFrame::nsScrollPref
-nsGfxScrollFrameInner::GetScrollPreference() const
-{
-  nsCOMPtr<nsIScrollableFrame> scrollable =
-    do_QueryInterface(NS_STATIC_CAST(nsIFrame*, mOuter));
-  ScrollbarStyles styles = scrollable->GetScrollbarStyles();
-
-  if (styles.mHorizontal == NS_STYLE_OVERFLOW_SCROLL &&
-      styles.mVertical == NS_STYLE_OVERFLOW_SCROLL) {
-    return nsIScrollableFrame::AlwaysScroll;
-  } else if (styles.mHorizontal == NS_STYLE_OVERFLOW_SCROLL) {
-    return nsIScrollableFrame::AlwaysScrollHorizontal;
-  } else if (styles.mVertical == NS_STYLE_OVERFLOW_SCROLL) {
-    return nsIScrollableFrame::AlwaysScrollVertical;
-  } else if (styles.mHorizontal == NS_STYLE_OVERFLOW_AUTO ||
-             styles.mVertical == NS_STYLE_OVERFLOW_AUTO) {
-    return nsIScrollableFrame::Auto;
-  } else {
-    return nsIScrollableFrame::NeverScroll;
-  }
+  NS_ASSERTION(result.mHorizontal != NS_STYLE_OVERFLOW_VISIBLE &&
+               result.mHorizontal != NS_STYLE_OVERFLOW_CLIP &&
+               result.mVertical != NS_STYLE_OVERFLOW_VISIBLE &&
+               result.mVertical != NS_STYLE_OVERFLOW_CLIP,
+               "scrollbars should not have been created");
+  return result;
 }
 
 void
@@ -1314,45 +1257,31 @@ nsGfxScrollFrameInner::CreateAnonymousContent(nsISupportsArray& aAnonymousChildr
     // allow scrollbars if this is the child of the viewport, because
     // we must be the scrollbars for the print preview window
     if (!parent || parent->GetType() != nsLayoutAtoms::viewportFrame) {
-      mNeverHasVerticalScrollbar = mNeverHasHorizontalScrollbar = PR_TRUE;
+      // If we just return early here, we'll never create content or
+      // frames an |mHScrollbarBox| and |mVScrollbarBox| will always be
+      // null.
       return;
     }
   }
 
-  nsIPresShell *shell = presContext->GetPresShell();
-  nsIDocument *document = nsnull;
-  if (shell)
-    document = shell->GetDocument();
+  nsIScrollableFrame *scrollable;
+  CallQueryInterface(mOuter, &scrollable);
 
-  // The anonymous <div> used by <inputs> never gets scrollbars.
-  nsCOMPtr<nsITextControlFrame> textFrame(do_QueryInterface(parent));
-  if (textFrame) {
-    // Make sure we are not a text area.
-    nsCOMPtr<nsIDOMHTMLTextAreaElement> textAreaElement(do_QueryInterface(parent->GetContent()));
-    if (!textAreaElement) {
-      mNeverHasVerticalScrollbar = mNeverHasHorizontalScrollbar = PR_TRUE;
-      return;
-    }
-  }
-
-  // create horizontal scrollbar
-  if (!document) {
+  ScrollbarStyles styles = scrollable->GetScrollbarStyles();
+  PRBool canHaveHorizontal = styles.mHorizontal != NS_STYLE_OVERFLOW_HIDDEN;
+  PRBool canHaveVertical = styles.mVertical != NS_STYLE_OVERFLOW_HIDDEN;
+  if (!canHaveHorizontal && !canHaveVertical)
+    // Nothing to do.
     return;
-  }
-
-  nsNodeInfoManager *nodeInfoManager = document->NodeInfoManager();
 
+  nsNodeInfoManager *nodeInfoManager =
+    presContext->GetDocument()->NodeInfoManager();
   nsCOMPtr<nsINodeInfo> nodeInfo;
   nodeInfoManager->GetNodeInfo(nsXULAtoms::scrollbar, nsnull,
                                kNameSpaceID_XUL, getter_AddRefs(nodeInfo));
 
   nsCOMPtr<nsIContent> content;
 
-  nsCOMPtr<nsIScrollableFrame> scrollable =
-    do_QueryInterface(NS_STATIC_CAST(nsIFrame*, mOuter));
-  ScrollbarStyles styles = scrollable->GetScrollbarStyles();
-  PRBool canHaveHorizontal = styles.mHorizontal == NS_STYLE_OVERFLOW_AUTO
-    || styles.mHorizontal == NS_STYLE_OVERFLOW_SCROLL;
   if (canHaveHorizontal) {
     NS_NewElement(getter_AddRefs(content), kNameSpaceID_XUL, nodeInfo);
     content->SetAttr(kNameSpaceID_None, nsXULAtoms::orient,
@@ -1360,8 +1289,6 @@ nsGfxScrollFrameInner::CreateAnonymousContent(nsISupportsArray& aAnonymousChildr
     aAnonymousChildren.AppendElement(content);
   }
 
-  PRBool canHaveVertical = styles.mVertical == NS_STYLE_OVERFLOW_AUTO
-    || styles.mVertical == NS_STYLE_OVERFLOW_SCROLL;
   if (canHaveVertical) {
     NS_NewElement(getter_AddRefs(content), kNameSpaceID_XUL, nodeInfo);
     content->SetAttr(kNameSpaceID_None, nsXULAtoms::orient,
@@ -1617,7 +1544,7 @@ PRBool
 nsGfxScrollFrameInner::AddRemoveScrollbar(nsBoxLayoutState& aState, nsRect& aScrollAreaSize, PRBool aOnTop, PRBool aHorizontal, PRBool aAdd)
 {
   if (aHorizontal) {
-     if (mNeverHasHorizontalScrollbar || !mHScrollbarBox)
+     if (!mHScrollbarBox)
        return PR_FALSE;
 
      nsSize hSize;
@@ -1634,7 +1561,7 @@ nsGfxScrollFrameInner::AddRemoveScrollbar(nsBoxLayoutState& aState, nsRect& aScr
 
      return fit;
   } else {
-     if (mNeverHasVerticalScrollbar || !mVScrollbarBox)
+     if (!mVScrollbarBox)
        return PR_FALSE;
 
      nsSize vSize;
@@ -1807,8 +1734,8 @@ nsGfxScrollFrameInner::Layout(nsBoxLayoutState& aState)
    (if we're the viewport and we added or removed a scrollbar).
    **************/
 
-  nsCOMPtr<nsIScrollableFrame> scrollableFrame =
-    do_QueryInterface(NS_STATIC_CAST(nsIFrame*, mOuter));
+  nsIScrollableFrame *scrollableFrame;
+  CallQueryInterface(mOuter, &scrollableFrame);
   ScrollbarStyles styles = scrollableFrame->GetScrollbarStyles();
 
   // Look at our style do we always have vertical or horizontal scrollbars?
diff --git a/mozilla/layout/html/base/src/nsGfxScrollFrame.h b/mozilla/layout/html/base/src/nsGfxScrollFrame.h
index 0faf48ee878..2333ead6481 100644
--- a/mozilla/layout/html/base/src/nsGfxScrollFrame.h
+++ b/mozilla/layout/html/base/src/nsGfxScrollFrame.h
@@ -63,8 +63,6 @@ public:
   typedef nsIScrollableFrame::ScrollbarStyles ScrollbarStyles;
   ScrollbarStyles GetScrollbarStylesFromFrame() const;
 
-  nsIScrollableFrame::nsScrollPref GetScrollPreference() const;
-
   // If a child frame was added or removed on the scrollframe,
   // reload our child frame list.
   // We need this if a scrollbar frame is recreated.
@@ -246,18 +244,12 @@ public:
   NS_IMETHOD GetScrollPosition(nsPresContext* aContext, nscoord &aX, nscoord& aY) const;
   NS_IMETHOD ScrollTo(nsPresContext* aContext, nscoord aX, nscoord aY, PRUint32 aFlags);
 
-  NS_IMETHOD SetScrollbarVisibility(nsPresContext* aPresContext,
-                                    PRBool aVerticalVisible,
-                                    PRBool aHorizontalVisible);
-
   NS_IMETHOD GetScrollbarBox(PRBool aVertical, nsIBox** aResult);
 
   NS_IMETHOD CurPosAttributeChanged(nsPresContext* aPresContext,
                                     nsIContent* aChild,
                                     PRInt32 aModType);
 
-  NS_IMETHOD  GetScrollPreference(nsPresContext* aPresContext, nsScrollPref* aScrollPreference) const;
-
   virtual void ScrollToRestoredPosition() {
     mInner.ScrollToRestoredPosition();
   }
@@ -377,18 +369,12 @@ public:
   NS_IMETHOD GetScrollPosition(nsPresContext* aContext, nscoord &aX, nscoord& aY) const;
   NS_IMETHOD ScrollTo(nsPresContext* aContext, nscoord aX, nscoord aY, PRUint32 aFlags);
 
-  NS_IMETHOD SetScrollbarVisibility(nsPresContext* aPresContext,
-                                    PRBool aVerticalVisible,
-                                    PRBool aHorizontalVisible);
-
   NS_IMETHOD GetScrollbarBox(PRBool aVertical, nsIBox** aResult);
 
   NS_IMETHOD CurPosAttributeChanged(nsPresContext* aPresContext,
                                     nsIContent* aChild,
                                     PRInt32 aModType);
 
-  NS_IMETHOD  GetScrollPreference(nsPresContext* aPresContext, nsScrollPref* aScrollPreference) const;
-
   virtual void ScrollToRestoredPosition() {
     mInner.ScrollToRestoredPosition();
   }
diff --git a/mozilla/layout/html/document/src/forms.css b/mozilla/layout/html/document/src/forms.css
index e23e8697c55..4ba29daa189 100644
--- a/mozilla/layout/html/document/src/forms.css
+++ b/mozilla/layout/html/document/src/forms.css
@@ -98,10 +98,6 @@ input {
   text-indent: 0;
 }
 
-input > .anonymous-div {
-  white-space : nowrap;
-}
-
 textarea {
   margin: 1px 0 1px 0;
   border: 2px inset ThreeDFace;
@@ -118,6 +114,7 @@ textarea {
   -moz-binding: url("resource://gre/res/builtin/platformHTMLBindings.xml#textAreas");
   -moz-appearance: textfield;
   text-indent: 0;
+  overflow: auto;
 }
 
 textarea > scrollbar {
@@ -136,6 +133,11 @@ input > .anonymous-div {
   text-decoration: inherit;
 }
 
+input > .anonymous-div {
+  white-space : nowrap;
+  overflow: hidden ! important;
+}
+
 select {
   margin: 0;
   border-color: ThreeDFace;
diff --git a/mozilla/layout/html/document/src/nsFrameFrame.cpp b/mozilla/layout/html/document/src/nsFrameFrame.cpp
index 63f215c82b8..449917e136e 100644
--- a/mozilla/layout/html/document/src/nsFrameFrame.cpp
+++ b/mozilla/layout/html/document/src/nsFrameFrame.cpp
@@ -617,6 +617,20 @@ nsSubDocumentFrame::GetDocShell(nsIDocShell **aDocShell)
   return mFrameLoader->GetDocShell(aDocShell);
 }
 
+inline PRInt32 ConvertOverflow(PRUint8 aOverflow)
+{
+  switch (aOverflow) {
+    case NS_STYLE_OVERFLOW_VISIBLE:
+    case NS_STYLE_OVERFLOW_AUTO:
+      return nsIScrollable::Scrollbar_Auto;
+    case NS_STYLE_OVERFLOW_HIDDEN:
+    case NS_STYLE_OVERFLOW_CLIP:
+      return nsIScrollable::Scrollbar_Never;
+    case NS_STYLE_OVERFLOW_SCROLL:
+      return nsIScrollable::Scrollbar_Always;
+  }
+}
+
 nsresult
 nsSubDocumentFrame::ShowDocShell()
 {
@@ -645,33 +659,11 @@ nsSubDocumentFrame::ShowDocShell()
   nsCOMPtr<nsIScrollable> sc(do_QueryInterface(docShell));
 
   if (sc) {
-    PRInt32 scrolling = GetStyleDisplay()->mOverflow;
-    PRInt32 scrollX, scrollY;
-    switch (scrolling) {
-      case NS_STYLE_OVERFLOW_CLIP:
-        scrollX = NS_STYLE_OVERFLOW_HIDDEN;
-        scrollY = NS_STYLE_OVERFLOW_HIDDEN;
-        break;
-      case NS_STYLE_OVERFLOW_SCROLLBARS_HORIZONTAL:
-        scrollX = NS_STYLE_OVERFLOW_SCROLL;
-        scrollY = NS_STYLE_OVERFLOW_HIDDEN;
-        break;
-      case NS_STYLE_OVERFLOW_SCROLLBARS_VERTICAL:
-        scrollX = NS_STYLE_OVERFLOW_HIDDEN;
-        scrollY = NS_STYLE_OVERFLOW_SCROLL;
-        break;
-      case NS_STYLE_OVERFLOW_VISIBLE:
-        scrollX = scrollY = NS_STYLE_OVERFLOW_AUTO;
-        break;
-      default:
-        scrollX = scrollY = scrolling;
-        break;
-    }
-
-    sc->SetDefaultScrollbarPreferences(nsIScrollable::ScrollOrientation_Y,
-                                       scrollX);
+    const nsStyleDisplay *disp = GetStyleDisplay();
     sc->SetDefaultScrollbarPreferences(nsIScrollable::ScrollOrientation_X,
-                                       scrollY);
+                                       ConvertOverflow(disp->mOverflowX));
+    sc->SetDefaultScrollbarPreferences(nsIScrollable::ScrollOrientation_Y,
+                                       ConvertOverflow(disp->mOverflowY));
   }
 
   PRInt32 itemType = nsIDocShellTreeItem::typeContent;
diff --git a/mozilla/layout/html/forms/src/nsTextControlFrame.cpp b/mozilla/layout/html/forms/src/nsTextControlFrame.cpp
index 89c062f027a..3b0243152b8 100644
--- a/mozilla/layout/html/forms/src/nsTextControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsTextControlFrame.cpp
@@ -1637,9 +1637,8 @@ nsTextControlFrame::CreateAnonymousContent(nsPresContext* aPresContext,
     // setting -moz-hidden-unscrollable overflow (NS_STYLE_OVERFLOW_CLIP)
     // doesn't paint the caret for some reason.
     const nsStyleDisplay* disp = GetStyleDisplay();
-    if (disp->mOverflow != NS_STYLE_OVERFLOW_AUTO &&  // this is the default
-        disp->mOverflow != NS_STYLE_OVERFLOW_VISIBLE &&
-        disp->mOverflow != NS_STYLE_OVERFLOW_CLIP) {
+    if (disp->mOverflowX != NS_STYLE_OVERFLOW_VISIBLE &&
+        disp->mOverflowX != NS_STYLE_OVERFLOW_CLIP) {
       rv = divContent->SetAttr(kNameSpaceID_None, nsHTMLAtoms::style,
                                NS_LITERAL_STRING("overflow: inherit;"),
                                PR_FALSE);
@@ -2997,16 +2996,6 @@ nsTextControlFrame::SetInitialChildList(nsPresContext* aPresContext,
   // than descending from the root frame of the frame hierarchy.
   first->AddStateBits(NS_FRAME_REFLOW_ROOT);
 
-//we must turn off scrollbars for singleline text controls
-  if (IsSingleLineTextControl()) 
-  {
-    nsIScrollableFrame *scrollableFrame = nsnull;
-    if (first)
-      first->QueryInterface(NS_GET_IID(nsIScrollableFrame), (void **) &scrollableFrame);
-    if (scrollableFrame)
-      scrollableFrame->SetScrollbarVisibility(aPresContext,PR_FALSE,PR_FALSE);
-  }
-
   //register keylistener
   nsCOMPtr<nsIDOMEventReceiver> erP;
   if (NS_SUCCEEDED(mContent->QueryInterface(NS_GET_IID(nsIDOMEventReceiver), getter_AddRefs(erP))) && erP)
diff --git a/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp b/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
index e9cc62a2bc2..8831a728542 100644
--- a/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
+++ b/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
@@ -2708,7 +2708,7 @@ nsCSSFrameConstructor::ConstructTableRowGroupFrame(nsIPresShell*            aPre
   rv = aTableCreator.CreateTableRowGroupFrame(&aNewFrame);
 
   nsIFrame* scrollFrame = nsnull;
-  if (IsScrollable(aPresContext, styleDisplay)) {
+  if (styleDisplay->IsScrollableOverflow()) {
     // Create an area container for the frame
     BuildScrollFrame(aPresShell, aPresContext, aState, aContent, aStyleContext, 
                      aNewFrame, parentFrame, nsnull, scrollFrame, aStyleContext);
@@ -3341,6 +3341,21 @@ nsCSSFrameConstructor::ConstructDocElementTableFrame(nsIPresShell*        aPresS
   return NS_OK;
 }
 
+static PRBool CheckOverflow(nsPresContext* aPresContext,
+                            const nsStyleDisplay* aDisplay)
+{
+  if (aDisplay->mOverflowX == NS_STYLE_OVERFLOW_VISIBLE)
+    return PR_FALSE;
+
+  if (aDisplay->mOverflowX == NS_STYLE_OVERFLOW_CLIP)
+    aPresContext->SetViewportOverflowOverride(NS_STYLE_OVERFLOW_HIDDEN,
+                                              NS_STYLE_OVERFLOW_HIDDEN);
+  else
+    aPresContext->SetViewportOverflowOverride(aDisplay->mOverflowX,
+                                              aDisplay->mOverflowY);
+  return PR_TRUE;
+}
+
 /**
  * This checks the root element and the HTML BODY, if any, for an "overflow" property
  * that should be applied to the viewport. If one is found then we return the
@@ -3354,7 +3369,8 @@ nsIContent*
 nsCSSFrameConstructor::PropagateScrollToViewport(nsPresContext* aPresContext)
 {
   // Set default
-  aPresContext->SetViewportOverflowOverride(NS_STYLE_OVERFLOW_AUTO);
+  aPresContext->SetViewportOverflowOverride(NS_STYLE_OVERFLOW_AUTO,
+                                            NS_STYLE_OVERFLOW_AUTO);
 
   // We never mess with the viewport scroll state
   // when printing or in print preview
@@ -3366,14 +3382,12 @@ nsCSSFrameConstructor::PropagateScrollToViewport(nsPresContext* aPresContext)
 
   // Check the style on the document root element
   nsStyleSet *styleSet = aPresContext->PresShell()->StyleSet();
-  nsRefPtr<nsStyleContext> styleContext;
-  styleContext = styleSet->ResolveStyleFor(docElement, nsnull);
-  if (!styleContext) {
+  nsRefPtr<nsStyleContext> rootStyle;
+  rootStyle = styleSet->ResolveStyleFor(docElement, nsnull);
+  if (!rootStyle) {
     return nsnull;
   }
-  const nsStyleDisplay* display = styleContext->GetStyleDisplay();
-  if (display->mOverflow != NS_STYLE_OVERFLOW_VISIBLE) {
-    aPresContext->SetViewportOverflowOverride(display->mOverflow);
+  if (CheckOverflow(aPresContext, rootStyle->GetStyleDisplay())) {
     // tell caller we stole the overflow style from the root element
     return docElement;
   }
@@ -3399,15 +3413,13 @@ nsCSSFrameConstructor::PropagateScrollToViewport(nsPresContext* aPresContext)
     return nsnull;
   }
 
-  nsRefPtr<nsStyleContext> bodyContext;
-  bodyContext = styleSet->ResolveStyleFor(bodyElement, styleContext);
-  if (!bodyContext) {
+  nsRefPtr<nsStyleContext> bodyStyle;
+  bodyStyle = styleSet->ResolveStyleFor(bodyElement, rootStyle);
+  if (!bodyStyle) {
     return nsnull;
   }
 
-  display = bodyContext->GetStyleDisplay();
-  if (display->mOverflow != NS_STYLE_OVERFLOW_VISIBLE) {
-    aPresContext->SetViewportOverflowOverride(display->mOverflow);
+  if (CheckOverflow(aPresContext, bodyStyle->GetStyleDisplay())) {
     // tell caller we stole the overflow style from the body element
     return bodyElement;
   }
@@ -3521,7 +3533,7 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
 
   // The document root should not be scrollable in any paginated context,
   // even in print preview.
-  PRBool isScrollable = IsScrollable(aPresContext, display)
+  PRBool isScrollable = display->IsScrollableOverflow()
     && !aPresContext->IsPaginated()
     && !propagatedScrollToViewport;
 
@@ -3796,7 +3808,6 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
   // for print-preview, but not when printing), then create a scroll frame that
   // will act as the scrolling mechanism for the viewport. 
   // XXX Do we even need a viewport when printing to a printer?
-  PRBool isScrollable = PR_TRUE;
 
   //isScrollable = PR_FALSE;
 
@@ -3809,8 +3820,6 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
   //  2) NS_STYLE_OVERFLOW_AUTO = scrollbars appear if needed
   //  3) NS_STYLE_OVERFLOW_SCROLL = scrollbars always
   // Only need to create a scroll frame/view for cases 2 and 3.
-  // Currently OVERFLOW_SCROLL isn't honored, as
-  // scrollportview::SetScrollPref is not implemented.
 
   PRBool isHTML = aDocElement->IsContentOfType(nsIContent::eHTML);
   PRBool isXUL = PR_FALSE;
@@ -3820,28 +3829,13 @@ nsCSSFrameConstructor::ConstructRootFrame(nsIPresShell*        aPresShell,
   }
 
   // Never create scrollbars for XUL documents
-#ifdef MOZ_XUL
-  if (isXUL) {
-    isScrollable = PR_FALSE;
-  } else 
-#endif
-  {
-    nsresult rv;
-    if (aPresContext) {
-      nsCOMPtr<nsISupports> container = aPresContext->GetContainer();
-      if (container) {
-        nsCOMPtr<nsIScrollable> scrollableContainer = do_QueryInterface(container, &rv);
-        if (NS_SUCCEEDED(rv) && scrollableContainer) {
-          PRInt32 scrolling = -1;
-          // XXX We should get prefs for X and Y and deal with these independently!
-          scrollableContainer->GetCurrentScrollbarPreferences(nsIScrollable::ScrollOrientation_Y,&scrolling);
-          if (NS_STYLE_OVERFLOW_HIDDEN == scrolling) {
-            isScrollable = PR_FALSE;
-          }
-          // XXX NS_STYLE_OVERFLOW_SCROLL should create 'always on' scrollbars
-        }
-      }
-    }
+  PRBool isScrollable = !isXUL;
+
+  // Never create scrollbars for frameset documents.
+  if (isHTML) {
+    nsCOMPtr<nsIHTMLDocument> htmlDoc = do_QueryInterface(mDocument);
+    if (htmlDoc && htmlDoc->GetIsFrameset())
+      isScrollable = PR_FALSE;
   }
 
   if (isPaginated) {
@@ -5480,7 +5474,7 @@ nsCSSFrameConstructor::ConstructXULFrame(nsIPresShell*            aPresShell,
         }
 
         // Boxes can scroll.
-        if (IsScrollable(aPresContext, display)) {
+        if (display->IsScrollableOverflow()) {
 
           nsIFrame* scrollPort = nsnull;
           if (listboxScrollPort) {
@@ -5580,7 +5574,7 @@ nsCSSFrameConstructor::ConstructXULFrame(nsIPresShell*            aPresShell,
 #endif
     }
 
-    if (mayBeScrollable && IsScrollable(aPresContext, display)) {
+    if (mayBeScrollable && display->IsScrollableOverflow()) {
       // set the top to be the newly created scrollframe
       BuildScrollFrame(aPresShell, aPresContext, aState, aContent,
                        aStyleContext, newFrame, aParentFrame, nsnull,
@@ -6088,7 +6082,7 @@ nsCSSFrameConstructor::ConstructFrameByDisplayType(nsIPresShell*            aPre
   // XXX Ignore tables for the time being
   if (aDisplay->IsBlockLevel() &&
       aDisplay->mDisplay != NS_STYLE_DISPLAY_TABLE &&
-      IsScrollable(aPresContext, aDisplay) &&
+      aDisplay->IsScrollableOverflow() &&
       !propagatedScrollToViewport) {
 
     if (!pseudoParent && !aState.mPseudoFrames.IsEmpty()) { // process pending pseudo frames
@@ -6494,25 +6488,6 @@ nsCSSFrameConstructor::ConstructFrameByDisplayType(nsIPresShell*            aPre
   return rv;
 }
 
-
-PRBool
-nsCSSFrameConstructor::IsScrollable(nsPresContext*       aPresContext,
-                                    const nsStyleDisplay* aDisplay)
-{
-  // For the time being it's scrollable if the overflow property is auto or
-  // scroll, regardless of whether the width or height is fixed in size
-  switch (aDisplay->mOverflow) {
-    case NS_STYLE_OVERFLOW_SCROLL:
-    case NS_STYLE_OVERFLOW_AUTO:
-    case NS_STYLE_OVERFLOW_HIDDEN:
-    case NS_STYLE_OVERFLOW_SCROLLBARS_HORIZONTAL:
-    case NS_STYLE_OVERFLOW_SCROLLBARS_VERTICAL:
-      return PR_TRUE;
-  }
-  return PR_FALSE;
-}
-
-
 nsresult 
 nsCSSFrameConstructor::InitAndRestoreFrame(nsPresContext*          aPresContext,
                                            nsFrameConstructorState& aState,
diff --git a/mozilla/layout/html/style/src/nsCSSFrameConstructor.h b/mozilla/layout/html/style/src/nsCSSFrameConstructor.h
index 229bc774c9e..e6803adac13 100644
--- a/mozilla/layout/html/style/src/nsCSSFrameConstructor.h
+++ b/mozilla/layout/html/style/src/nsCSSFrameConstructor.h
@@ -685,8 +685,6 @@ private:
                                       nsIContent*               aChild,
                                       nsIDOMHTMLSelectElement*  aSelectElement);
 
-  PRBool IsScrollable(nsPresContext* aPresContext, const nsStyleDisplay* aDisplay);
-
   nsIFrame* GetFrameFor(nsIPresShell*   aPresShell,
                         nsPresContext* aPresContext,
                         nsIContent*     aContent);
diff --git a/mozilla/layout/html/table/src/nsTableCellFrame.cpp b/mozilla/layout/html/table/src/nsTableCellFrame.cpp
index e4c52e98709..8a67f737245 100644
--- a/mozilla/layout/html/table/src/nsTableCellFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableCellFrame.cpp
@@ -432,10 +432,9 @@ nsTableCellFrame::Paint(nsPresContext*      aPresContext,
                                     nsClipCombine_kIntersect);
     }
     else {
-      if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflow ||
-          // XXXldb HIDDEN should really create a scrollframe,
-          // but test here since it doesn't.
-          NS_STYLE_OVERFLOW_HIDDEN == disp->mOverflow ||
+      // XXXldb HIDDEN should really create a scrollframe,
+      // but use |IsTableClip| here since it doesn't.
+      if (disp->IsTableClip() ||
           HasPctOverHeight()) {
         aRenderingContext.PushState();
         pushed = PR_TRUE;
diff --git a/mozilla/layout/html/table/src/nsTableFrame.cpp b/mozilla/layout/html/table/src/nsTableFrame.cpp
index fe1805c004a..0ce731528d5 100644
--- a/mozilla/layout/html/table/src/nsTableFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableFrame.cpp
@@ -1360,11 +1360,8 @@ nsTableFrame::PaintChildren(nsPresContext*      aPresContext,
                             const nsRect&        aDirtyRect,
                             nsFramePaintLayer    aWhichLayer,
                             PRUint32             aFlags)
-
 {
-  PRUint8 overflow = GetStyleDisplay()->mOverflow;
-  PRBool clip = overflow == NS_STYLE_OVERFLOW_CLIP ||
-                overflow == NS_STYLE_OVERFLOW_HIDDEN;
+  PRBool clip = GetStyleDisplay()->IsTableClip();
   // If overflow is hidden then set the clip rect so that children don't
   // leak out of us. Note that because overflow'-clip' only applies to
   // the content area we do this after painting the border and background
@@ -2076,7 +2073,7 @@ NS_METHOD nsTableFrame::Reflow(nsPresContext*          aPresContext,
   if (aDesiredSize.mFlags & NS_REFLOW_CALC_MAX_WIDTH) {
     aDesiredSize.mMaximumWidth = GetPreferredWidth();
   }
-  if (NS_STYLE_OVERFLOW_CLIP != aReflowState.mStyleDisplay->mOverflow) {
+  if (!aReflowState.mStyleDisplay->IsTableClip()) {
     // collapsed border may leak out
     nsMargin bcMargin = GetBCMargin(aPresContext);
     nsRect tableRect(0, 0, aDesiredSize.width, aDesiredSize.height) ;
diff --git a/mozilla/layout/html/table/src/nsTableOuterFrame.cpp b/mozilla/layout/html/table/src/nsTableOuterFrame.cpp
index 127772f39a6..e7eb8565e6b 100644
--- a/mozilla/layout/html/table/src/nsTableOuterFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableOuterFrame.cpp
@@ -333,9 +333,7 @@ nsTableOuterFrame::Paint(nsPresContext*      aPresContext,
   
   // If overflow is hidden then set the clip rect so that children
   // don't leak out of us
-  PRUint8 overflow = GetStyleDisplay()->mOverflow;
-  PRBool clip = overflow == NS_STYLE_OVERFLOW_CLIP ||
-                overflow == NS_STYLE_OVERFLOW_HIDDEN;
+  PRBool clip = GetStyleDisplay()->IsTableClip();
   if (clip) {
     aRenderingContext.PushState();
     SetOverflowClipRect(aRenderingContext);
diff --git a/mozilla/layout/html/table/src/nsTableRowFrame.cpp b/mozilla/layout/html/table/src/nsTableRowFrame.cpp
index ddc21633fbf..3a27edb0afb 100644
--- a/mozilla/layout/html/table/src/nsTableRowFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableRowFrame.cpp
@@ -555,9 +555,7 @@ NS_METHOD nsTableRowFrame::Paint(nsPresContext*      aPresContext,
     aFlags |= NS_PAINT_FLAG_TABLE_BG_PAINT;
   }
 
-  PRUint8 overflow = GetStyleDisplay()->mOverflow;
-  PRBool clip = overflow == NS_STYLE_OVERFLOW_CLIP ||
-                overflow == NS_STYLE_OVERFLOW_HIDDEN;
+  PRBool clip = GetStyleDisplay()->IsTableClip();
   if (clip) {
     aRenderingContext.PushState();
     SetOverflowClipRect(aRenderingContext);
diff --git a/mozilla/layout/style/forms.css b/mozilla/layout/style/forms.css
index e23e8697c55..4ba29daa189 100644
--- a/mozilla/layout/style/forms.css
+++ b/mozilla/layout/style/forms.css
@@ -98,10 +98,6 @@ input {
   text-indent: 0;
 }
 
-input > .anonymous-div {
-  white-space : nowrap;
-}
-
 textarea {
   margin: 1px 0 1px 0;
   border: 2px inset ThreeDFace;
@@ -118,6 +114,7 @@ textarea {
   -moz-binding: url("resource://gre/res/builtin/platformHTMLBindings.xml#textAreas");
   -moz-appearance: textfield;
   text-indent: 0;
+  overflow: auto;
 }
 
 textarea > scrollbar {
@@ -136,6 +133,11 @@ input > .anonymous-div {
   text-decoration: inherit;
 }
 
+input > .anonymous-div {
+  white-space : nowrap;
+  overflow: hidden ! important;
+}
+
 select {
   margin: 0;
   border-color: ThreeDFace;
diff --git a/mozilla/layout/style/nsCSSDeclaration.cpp b/mozilla/layout/style/nsCSSDeclaration.cpp
index 66ad6686027..84df769f526 100644
--- a/mozilla/layout/style/nsCSSDeclaration.cpp
+++ b/mozilla/layout/style/nsCSSDeclaration.cpp
@@ -500,6 +500,7 @@ nsCSSDeclaration::GetValue(nsCSSProperty aProperty,
 
   // shorthands
   // XXX What about checking the consistency of '!important'?
+  // XXXldb Can we share shorthand logic with ToString?
   switch (aProperty) {
     case eCSSProperty_margin: 
     case eCSSProperty_padding: 
@@ -629,6 +630,14 @@ nsCSSDeclaration::GetValue(nsCSSProperty aProperty,
         aValue.Append(PRUnichar(' '));
       AppendValueToString(eCSSProperty_list_style_image, aValue);
       break;
+    case eCSSProperty_overflow: {
+      nsCSSValue xValue, yValue;
+      GetValueOrImportantValue(eCSSProperty_overflow_x, xValue);
+      GetValueOrImportantValue(eCSSProperty_overflow_y, yValue);
+      if (xValue == yValue)
+        AppendValueToString(eCSSProperty_overflow_x, aValue);
+      break;
+    }
     case eCSSProperty_pause: {
       if (AppendValueToString(eCSSProperty_pause_after, aValue)) {
         aValue.Append(PRUnichar(' '));
@@ -968,6 +977,27 @@ nsCSSDeclaration::UseBackgroundPosition(nsAString & aString,
   aBgPositionY = 0;
 }
 
+void
+nsCSSDeclaration::TryOverflowShorthand(nsAString & aString,
+                                       PRInt32 & aOverflowX,
+                                       PRInt32 & aOverflowY) const
+{
+  PRBool isImportant;
+  if (aOverflowX && aOverflowY &&
+      AllPropertiesSameImportance(aOverflowX, aOverflowY,
+                                  0, 0, 0, 0, isImportant)) {
+    nsCSSValue xValue, yValue;
+    GetValueOrImportantValue(eCSSProperty_overflow_x, xValue);
+    GetValueOrImportantValue(eCSSProperty_overflow_y, yValue);
+    if (xValue == yValue) {
+      AppendCSSValueToString(eCSSProperty_overflow_x, xValue, aString);
+      AppendImportanceToString(isImportant, aString);
+      aString.AppendLiteral("; ");
+      aOverflowX = aOverflowY = 0;
+    }
+  }
+}
+
 #define NS_CASE_OUTPUT_PROPERTY_VALUE(_prop, _index) \
 case _prop: \
           if (_index) { \
@@ -1012,6 +1042,7 @@ nsCSSDeclaration::ToString(nsAString& aString) const
   PRInt32 paddingTop = 0, paddingBottom = 0, paddingLeft = 0, paddingRight = 0;
   PRInt32 bgColor = 0, bgImage = 0, bgRepeat = 0, bgAttachment = 0;
   PRInt32 bgPositionX = 0, bgPositionY = 0;
+  PRInt32 overflowX = 0, overflowY = 0;
   PRUint32 borderPropertiesSet = 0, finalBorderPropertiesToSet = 0;
   for (index = 0; index < count; index++) {
     nsCSSProperty property = OrderValueAt(index);
@@ -1055,23 +1086,27 @@ nsCSSDeclaration::ToString(nsAString& aString) const
         PropertyIsSet(borderRightColor, index, borderPropertiesSet, B_BORDER_RIGHT_COLOR);
         break;
 
-      case eCSSProperty_margin_top:            marginTop         = index+1; break;
-      case eCSSProperty_margin_bottom:         marginBottom      = index+1; break;
-      case eCSSProperty_margin_left_value:     marginLeft        = index+1; break;
-      case eCSSProperty_margin_right_value:    marginRight       = index+1; break;
+      case eCSSProperty_margin_top:            marginTop     = index+1; break;
+      case eCSSProperty_margin_bottom:         marginBottom  = index+1; break;
+      case eCSSProperty_margin_left_value:     marginLeft    = index+1; break;
+      case eCSSProperty_margin_right_value:    marginRight   = index+1; break;
 
-      case eCSSProperty_padding_top:           paddingTop        = index+1; break;
-      case eCSSProperty_padding_bottom:        paddingBottom     = index+1; break;
-      case eCSSProperty_padding_left_value:    paddingLeft       = index+1; break;
-      case eCSSProperty_padding_right_value:   paddingRight      = index+1; break;
+      case eCSSProperty_padding_top:           paddingTop    = index+1; break;
+      case eCSSProperty_padding_bottom:        paddingBottom = index+1; break;
+      case eCSSProperty_padding_left_value:    paddingLeft   = index+1; break;
+      case eCSSProperty_padding_right_value:   paddingRight  = index+1; break;
 
-      case eCSSProperty_background_color:      bgColor           = index+1; break;
-      case eCSSProperty_background_image:      bgImage           = index+1; break;
-      case eCSSProperty_background_repeat:     bgRepeat          = index+1; break;
-      case eCSSProperty_background_attachment: bgAttachment      = index+1; break;
-      case eCSSProperty_background_x_position: bgPositionX       = index+1; break;
-      case eCSSProperty_background_y_position: bgPositionY       = index+1; break;
-      default:                                 ;
+      case eCSSProperty_background_color:      bgColor       = index+1; break;
+      case eCSSProperty_background_image:      bgImage       = index+1; break;
+      case eCSSProperty_background_repeat:     bgRepeat      = index+1; break;
+      case eCSSProperty_background_attachment: bgAttachment  = index+1; break;
+      case eCSSProperty_background_x_position: bgPositionX   = index+1; break;
+      case eCSSProperty_background_y_position: bgPositionY   = index+1; break;
+
+      case eCSSProperty_overflow_x:            overflowX     = index+1; break;
+      case eCSSProperty_overflow_y:            overflowY     = index+1; break;
+
+      default: break;
     }
   }
 
@@ -1139,6 +1174,7 @@ nsCSSDeclaration::ToString(nsAString& aString) const
   TryBackgroundShorthand(aString,
                          bgColor, bgImage, bgRepeat, bgAttachment,
                          bgPositionX, bgPositionY);
+  TryOverflowShorthand(aString, overflowX, overflowY);
 
   for (index = 0; index < count; index++) {
     nsCSSProperty property = OrderValueAt(index);
@@ -1214,6 +1250,9 @@ nsCSSDeclaration::ToString(nsAString& aString) const
         break;
       }
 
+      NS_CASE_OUTPUT_PROPERTY_VALUE(eCSSProperty_overflow_x, overflowX)
+      NS_CASE_OUTPUT_PROPERTY_VALUE(eCSSProperty_overflow_y, overflowY)
+
       case eCSSProperty_margin_left_ltr_source:
       case eCSSProperty_margin_left_rtl_source:
       case eCSSProperty_margin_right_ltr_source:
diff --git a/mozilla/layout/style/nsCSSDeclaration.h b/mozilla/layout/style/nsCSSDeclaration.h
index fe7a3bb0d83..ead908df86a 100644
--- a/mozilla/layout/style/nsCSSDeclaration.h
+++ b/mozilla/layout/style/nsCSSDeclaration.h
@@ -190,6 +190,8 @@ private:
   void  UseBackgroundPosition(nsAString & aString,
                               PRInt32 & aBgPositionX,
                               PRInt32 & aBgPositionY) const;
+  void  TryOverflowShorthand(nsAString & aString,
+                             PRInt32 & aOverflowX, PRInt32 & aOverflowY) const;
 
   PRBool   AllPropertiesSameImportance(PRInt32 aFirst, PRInt32 aSecond,
                                        PRInt32 aThird, PRInt32 aFourth,
diff --git a/mozilla/layout/style/nsCSSParser.cpp b/mozilla/layout/style/nsCSSParser.cpp
index 58f254ef2d8..8a92cad5468 100644
--- a/mozilla/layout/style/nsCSSParser.cpp
+++ b/mozilla/layout/style/nsCSSParser.cpp
@@ -261,6 +261,7 @@ protected:
 #ifdef ENABLE_OUTLINE
   PRBool ParseOutline(nsresult& aErrorCode);
 #endif
+  PRBool ParseOverflow(nsresult& aErrorCode);
   PRBool ParsePadding(nsresult& aErrorCode);
   PRBool ParsePause(nsresult& aErrorCode);
   PRBool ParsePlayDuring(nsresult& aErrorCode);
@@ -4024,6 +4025,8 @@ PRBool CSSParserImpl::ParseProperty(nsresult& aErrorCode,
   case eCSSProperty__moz_outline:
     return ParseOutline(aErrorCode);
 #endif
+  case eCSSProperty_overflow:
+    return ParseOverflow(aErrorCode);
   case eCSSProperty_padding:
     return ParsePadding(aErrorCode);
   case eCSSProperty_padding_end:
@@ -4157,6 +4160,7 @@ PRBool CSSParserImpl::ParseSingleValueProperty(nsresult& aErrorCode,
   case eCSSProperty__moz_outline:
   case eCSSProperty__moz_outline_radius:
 #endif
+  case eCSSProperty_overflow:
   case eCSSProperty_padding:
   case eCSSProperty_padding_end:
   case eCSSProperty_padding_left:
@@ -4443,9 +4447,10 @@ PRBool CSSParserImpl::ParseSingleValueProperty(nsresult& aErrorCode,
     return ParseVariant(aErrorCode, aValue, VARIANT_HKL,
                         nsCSSProps::kBorderWidthKTable);
 #endif
-  case eCSSProperty_overflow:
+  case eCSSProperty_overflow_x:
+  case eCSSProperty_overflow_y:
     return ParseVariant(aErrorCode, aValue, VARIANT_AHK,
-                        nsCSSProps::kOverflowKTable);
+                        nsCSSProps::kOverflowSubKTable);
   case eCSSProperty_padding_bottom:
   case eCSSProperty_padding_end_value: // for internal use
   case eCSSProperty_padding_left_value: // for internal use
@@ -5554,6 +5559,33 @@ PRBool CSSParserImpl::ParseOutline(nsresult& aErrorCode)
 }
 #endif
 
+PRBool CSSParserImpl::ParseOverflow(nsresult& aErrorCode)
+{
+  nsCSSValue overflow;
+  if (!ParseVariant(aErrorCode, overflow, VARIANT_AHK,
+                   nsCSSProps::kOverflowKTable) ||
+      !ExpectEndProperty(aErrorCode, PR_TRUE))
+    return PR_FALSE;
+
+  nsCSSValue overflowX(overflow);
+  nsCSSValue overflowY(overflow);
+  if (eCSSUnit_Enumerated == overflow.GetUnit())
+    switch(overflow.GetIntValue()) {
+      case NS_STYLE_OVERFLOW_SCROLLBARS_HORIZONTAL:
+        overflowX.SetIntValue(NS_STYLE_OVERFLOW_SCROLL, eCSSUnit_Enumerated);
+        overflowY.SetIntValue(NS_STYLE_OVERFLOW_HIDDEN, eCSSUnit_Enumerated);
+        break;
+      case NS_STYLE_OVERFLOW_SCROLLBARS_VERTICAL:
+        overflowX.SetIntValue(NS_STYLE_OVERFLOW_HIDDEN, eCSSUnit_Enumerated);
+        overflowY.SetIntValue(NS_STYLE_OVERFLOW_SCROLL, eCSSUnit_Enumerated);
+        break;
+    }
+  AppendValue(eCSSProperty_overflow_x, overflowX);
+  AppendValue(eCSSProperty_overflow_y, overflowY);
+  aErrorCode = NS_OK;
+  return PR_TRUE;
+}
+
 PRBool CSSParserImpl::ParsePadding(nsresult& aErrorCode)
 {
   static const nsCSSProperty kPaddingSideIDs[] = {
diff --git a/mozilla/layout/style/nsCSSPropList.h b/mozilla/layout/style/nsCSSPropList.h
index cae3293be7e..bdab54964bd 100644
--- a/mozilla/layout/style/nsCSSPropList.h
+++ b/mozilla/layout/style/nsCSSPropList.h
@@ -406,7 +406,9 @@ CSS_PROP_SHORTHAND(-moz-outline, _moz_outline, MozOutline)  // XXX This is tempo
 CSS_PROP_OUTLINE(-moz-outline-color, _moz_outline_color, MozOutlineColor, Margin, mOutlineColor, eCSSType_Value, PR_FALSE, kOutlineColorKTable) // XXX bug 48973
 CSS_PROP_OUTLINE(-moz-outline-style, _moz_outline_style, MozOutlineStyle, Margin, mOutlineStyle, eCSSType_Value, PR_FALSE, kBorderStyleKTable) // XXX bug 48973
 CSS_PROP_OUTLINE(-moz-outline-width, _moz_outline_width, MozOutlineWidth, Margin, mOutlineWidth, eCSSType_Value, PR_TRUE, kBorderWidthKTable) // XXX bug 48973
-CSS_PROP_DISPLAY(overflow, overflow, Overflow, Display, mOverflow, eCSSType_Value, PR_FALSE, kOverflowKTable)
+CSS_PROP_SHORTHAND(overflow, overflow, Overflow)
+CSS_PROP_DISPLAY(overflow-x, overflow_x, OverflowX, Display, mOverflowX, eCSSType_Value, PR_FALSE, kOverflowSubKTable)
+CSS_PROP_DISPLAY(overflow-y, overflow_y, OverflowY, Display, mOverflowY, eCSSType_Value, PR_FALSE, kOverflowSubKTable)
 CSS_PROP_SHORTHAND(padding, padding, Padding)
 CSS_PROP_PADDING(padding-bottom, padding_bottom, PaddingBottom, Margin, mPadding.mBottom, eCSSType_Value, PR_TRUE, nsnull)
 CSS_PROP_SHORTHAND(-moz-padding-end, padding_end, MozPaddingEnd)
diff --git a/mozilla/layout/style/nsCSSProps.cpp b/mozilla/layout/style/nsCSSProps.cpp
index e90497b114c..e9d144ce36e 100644
--- a/mozilla/layout/style/nsCSSProps.cpp
+++ b/mozilla/layout/style/nsCSSProps.cpp
@@ -679,6 +679,7 @@ const PRInt32 nsCSSProps::kOverflowKTable[] = {
   eCSSKeyword_visible, NS_STYLE_OVERFLOW_VISIBLE,
   eCSSKeyword_hidden, NS_STYLE_OVERFLOW_HIDDEN,
   eCSSKeyword_scroll, NS_STYLE_OVERFLOW_SCROLL,
+  // Deprecated:
   eCSSKeyword__moz_scrollbars_none, NS_STYLE_OVERFLOW_HIDDEN,
   eCSSKeyword__moz_scrollbars_horizontal, NS_STYLE_OVERFLOW_SCROLLBARS_HORIZONTAL,
   eCSSKeyword__moz_scrollbars_vertical, NS_STYLE_OVERFLOW_SCROLLBARS_VERTICAL,
@@ -686,6 +687,15 @@ const PRInt32 nsCSSProps::kOverflowKTable[] = {
   -1,-1
 };
 
+const PRInt32 nsCSSProps::kOverflowSubKTable[] = {
+  eCSSKeyword_visible, NS_STYLE_OVERFLOW_VISIBLE,
+  eCSSKeyword_hidden, NS_STYLE_OVERFLOW_HIDDEN,
+  eCSSKeyword_scroll, NS_STYLE_OVERFLOW_SCROLL,
+  // Deprecated:
+  eCSSKeyword__moz_hidden_unscrollable, NS_STYLE_OVERFLOW_CLIP,
+  -1,-1
+};
+
 const PRInt32 nsCSSProps::kPageBreakKTable[] = {
   eCSSKeyword_always, NS_STYLE_PAGE_BREAK_ALWAYS,
   eCSSKeyword_avoid, NS_STYLE_PAGE_BREAK_AVOID,
@@ -1316,6 +1326,12 @@ static const nsCSSProperty gMozOutlineSubpropTable[] = {
   eCSSProperty_UNKNOWN
 };
 
+static const nsCSSProperty gOverflowSubpropTable[] = {
+  eCSSProperty_overflow_x,
+  eCSSProperty_overflow_y,
+  eCSSProperty_UNKNOWN
+};
+
 static const nsCSSProperty gPaddingSubpropTable[] = {
   // Code relies on these being in top-right-bottom-left order.
   eCSSProperty_padding_top,
diff --git a/mozilla/layout/style/nsCSSProps.h b/mozilla/layout/style/nsCSSProps.h
index 0da4a705dcc..57c70d3e45a 100644
--- a/mozilla/layout/style/nsCSSProps.h
+++ b/mozilla/layout/style/nsCSSProps.h
@@ -149,6 +149,7 @@ public:
   static const PRInt32 kListStyleKTable[];
   static const PRInt32 kOutlineColorKTable[];
   static const PRInt32 kOverflowKTable[];
+  static const PRInt32 kOverflowSubKTable[];
   static const PRInt32 kPageBreakKTable[];
   static const PRInt32 kPageBreakInsideKTable[];
   static const PRInt32 kPageMarksKTable[];
diff --git a/mozilla/layout/style/nsCSSStruct.cpp b/mozilla/layout/style/nsCSSStruct.cpp
index 1470519b68b..a4cac3eaa95 100644
--- a/mozilla/layout/style/nsCSSStruct.cpp
+++ b/mozilla/layout/style/nsCSSStruct.cpp
@@ -487,7 +487,8 @@ nsCSSDisplay::nsCSSDisplay(const nsCSSDisplay& aCopy)
     mFloat(aCopy.mFloat),
     mClear(aCopy.mClear),
     mClip(aCopy.mClip),
-    mOverflow(aCopy.mOverflow),
+    mOverflowX(aCopy.mOverflowX),
+    mOverflowY(aCopy.mOverflowY),
     mVisibility(aCopy.mVisibility),
     mOpacity(aCopy.mOpacity),
     // temp fix for bug 24000
@@ -523,7 +524,8 @@ void nsCSSDisplay::List(FILE* out, PRInt32 aIndent) const
   fputs(NS_LossyConvertUCS2toASCII(buffer).get(), out);
   mClip.List(out, eCSSProperty_clip);
   buffer.SetLength(0);
-  mOverflow.AppendToString(buffer, eCSSProperty_overflow);
+  mOverflowX.AppendToString(buffer, eCSSProperty_overflow_x);
+  mOverflowY.AppendToString(buffer, eCSSProperty_overflow_y);
   fputs(NS_LossyConvertUCS2toASCII(buffer).get(), out);
 }
 #endif
diff --git a/mozilla/layout/style/nsCSSStruct.h b/mozilla/layout/style/nsCSSStruct.h
index a5a06ad9d83..ae641fcff59 100644
--- a/mozilla/layout/style/nsCSSStruct.h
+++ b/mozilla/layout/style/nsCSSStruct.h
@@ -234,7 +234,8 @@ struct nsCSSDisplay : public nsCSSStruct  {
   nsCSSValue mFloat;
   nsCSSValue mClear;
   nsCSSRect  mClip;
-  nsCSSValue mOverflow;
+  nsCSSValue mOverflowX;
+  nsCSSValue mOverflowY;
   nsCSSValue mVisibility;
   nsCSSValue mOpacity;
 
diff --git a/mozilla/layout/style/nsComputedDOMStyle.cpp b/mozilla/layout/style/nsComputedDOMStyle.cpp
index af6f875d0f8..dbdd5b85c35 100644
--- a/mozilla/layout/style/nsComputedDOMStyle.cpp
+++ b/mozilla/layout/style/nsComputedDOMStyle.cpp
@@ -2344,10 +2344,56 @@ nsComputedDOMStyle::GetOverflow(nsIFrame *aFrame,
   const nsStyleDisplay* display = nsnull;
   GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display, aFrame);
 
-  if (display && display->mOverflow != NS_STYLE_OVERFLOW_AUTO) {
+  if (display && display->mOverflowX == display->mOverflowY) {
+    if (display->mOverflowX != NS_STYLE_OVERFLOW_AUTO) {
+      const nsAFlatCString& overflow =
+        nsCSSProps::SearchKeywordTable(display->mOverflowX,
+                                       nsCSSProps::kOverflowKTable);
+      val->SetIdent(overflow);
+    } else {
+      val->SetIdent(nsLayoutAtoms::autoAtom);
+    }
+  } // XXX else what?
+
+  return CallQueryInterface(val, aValue);
+}
+
+nsresult
+nsComputedDOMStyle::GetOverflowX(nsIFrame *aFrame,
+                                 nsIDOMCSSValue** aValue)
+{
+  nsROCSSPrimitiveValue* val = GetROCSSPrimitiveValue();
+  NS_ENSURE_TRUE(val, NS_ERROR_OUT_OF_MEMORY);
+
+  const nsStyleDisplay* display = nsnull;
+  GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display, aFrame);
+
+  if (display && display->mOverflowX != NS_STYLE_OVERFLOW_AUTO) {
     const nsAFlatCString& overflow =
-      nsCSSProps::SearchKeywordTable(display->mOverflow,
-                                     nsCSSProps::kOverflowKTable);
+      nsCSSProps::SearchKeywordTable(display->mOverflowX,
+                                     nsCSSProps::kOverflowSubKTable);
+    val->SetIdent(overflow);
+  } else {
+    val->SetIdent(nsLayoutAtoms::autoAtom);
+  }
+
+  return CallQueryInterface(val, aValue);
+}
+
+nsresult
+nsComputedDOMStyle::GetOverflowY(nsIFrame *aFrame,
+                                 nsIDOMCSSValue** aValue)
+{
+  nsROCSSPrimitiveValue* val = GetROCSSPrimitiveValue();
+  NS_ENSURE_TRUE(val, NS_ERROR_OUT_OF_MEMORY);
+
+  const nsStyleDisplay* display = nsnull;
+  GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display, aFrame);
+
+  if (display && display->mOverflowY != NS_STYLE_OVERFLOW_AUTO) {
+    const nsAFlatCString& overflow =
+      nsCSSProps::SearchKeywordTable(display->mOverflowY,
+                                     nsCSSProps::kOverflowSubKTable);
     val->SetIdent(overflow);
   } else {
     val->SetIdent(nsLayoutAtoms::autoAtom);
@@ -3533,6 +3579,8 @@ nsComputedDOMStyle::GetQueryablePropertyMap(PRUint32* aLength)
     // COMPUTED_STYLE_MAP_ENTRY(outline_style,              OutlineStyle),
     // COMPUTED_STYLE_MAP_ENTRY(outline_width,              OutlineWidth),
     COMPUTED_STYLE_MAP_ENTRY(overflow,                      Overflow),
+    COMPUTED_STYLE_MAP_ENTRY(overflow_x,                    OverflowX),
+    COMPUTED_STYLE_MAP_ENTRY(overflow_y,                    OverflowY),
     //// COMPUTED_STYLE_MAP_ENTRY(padding,                  Padding),
     COMPUTED_STYLE_MAP_ENTRY(padding_bottom,                PaddingBottom),
     COMPUTED_STYLE_MAP_ENTRY(padding_left,                  PaddingLeft),
diff --git a/mozilla/layout/style/nsComputedDOMStyle.h b/mozilla/layout/style/nsComputedDOMStyle.h
index f5bff76c134..89ea422be79 100644
--- a/mozilla/layout/style/nsComputedDOMStyle.h
+++ b/mozilla/layout/style/nsComputedDOMStyle.h
@@ -272,6 +272,8 @@ private:
   nsresult GetPosition(nsIFrame *aFrame, nsIDOMCSSValue** aValue);
   nsresult GetClip(nsIFrame *aFrame, nsIDOMCSSValue** aValue);
   nsresult GetOverflow(nsIFrame *aFrame, nsIDOMCSSValue** aValue);
+  nsresult GetOverflowX(nsIFrame *aFrame, nsIDOMCSSValue** aValue);
+  nsresult GetOverflowY(nsIFrame *aFrame, nsIDOMCSSValue** aValue);
 
   /* User interface properties */
   nsresult GetCursor(nsIFrame *aFrame, nsIDOMCSSValue** aValue);
diff --git a/mozilla/layout/style/nsHTMLCSSStyleSheet.cpp b/mozilla/layout/style/nsHTMLCSSStyleSheet.cpp
index cf65efc5a68..0ade20aeea4 100644
--- a/mozilla/layout/style/nsHTMLCSSStyleSheet.cpp
+++ b/mozilla/layout/style/nsHTMLCSSStyleSheet.cpp
@@ -184,7 +184,8 @@ CSSDisablePropsRule::CommonMapRuleInfoInto(nsRuleData* aData)
     aData->mDisplayData->mPosition = staticposition;
 
     nsCSSValue visible(NS_STYLE_OVERFLOW_VISIBLE, eCSSUnit_Enumerated);
-    aData->mDisplayData->mOverflow = visible;
+    aData->mDisplayData->mOverflowX = visible;
+    aData->mDisplayData->mOverflowY = visible;
 
     // Nobody will care about 'break-before' or 'break-after', since
     // they only apply to blocks (assuming we implement them correctly).
diff --git a/mozilla/layout/style/nsRuleNode.cpp b/mozilla/layout/style/nsRuleNode.cpp
index 70b8ddb1114..2c0a7cafc20 100644
--- a/mozilla/layout/style/nsRuleNode.cpp
+++ b/mozilla/layout/style/nsRuleNode.cpp
@@ -2614,16 +2614,55 @@ nsRuleNode::ComputeDisplayData(nsStyleStruct* aStartStruct,
     display->mFloats = parentDisplay->mFloats;
   }
 
-  // overflow: enum, auto, inherit
-  if (eCSSUnit_Enumerated == displayData.mOverflow.GetUnit()) {
-    display->mOverflow = displayData.mOverflow.GetIntValue();
+  // overflow-x: enum, auto, inherit
+  if (eCSSUnit_Enumerated == displayData.mOverflowX.GetUnit()) {
+    display->mOverflowX = displayData.mOverflowX.GetIntValue();
   }
-  else if (eCSSUnit_Auto == displayData.mOverflow.GetUnit()) {
-    display->mOverflow = NS_STYLE_OVERFLOW_AUTO;
+  else if (eCSSUnit_Auto == displayData.mOverflowX.GetUnit()) {
+    display->mOverflowX = NS_STYLE_OVERFLOW_AUTO;
   }
-  else if (eCSSUnit_Inherit == displayData.mOverflow.GetUnit()) {
+  else if (eCSSUnit_Inherit == displayData.mOverflowX.GetUnit()) {
     inherited = PR_TRUE;
-    display->mOverflow = parentDisplay->mOverflow;
+    display->mOverflowX = parentDisplay->mOverflowX;
+  }
+
+  // overflow-y: enum, auto, inherit
+  if (eCSSUnit_Enumerated == displayData.mOverflowY.GetUnit()) {
+    display->mOverflowY = displayData.mOverflowY.GetIntValue();
+  }
+  else if (eCSSUnit_Auto == displayData.mOverflowY.GetUnit()) {
+    display->mOverflowY = NS_STYLE_OVERFLOW_AUTO;
+  }
+  else if (eCSSUnit_Inherit == displayData.mOverflowY.GetUnit()) {
+    inherited = PR_TRUE;
+    display->mOverflowY = parentDisplay->mOverflowY;
+  }
+
+  // CSS3 overflow-x and overflow-y require some fixup as well in some
+  // cases.  NS_STYLE_OVERFLOW_VISIBLE and NS_STYLE_OVERFLOW_CLIP are
+  // meaningful only when used in both dimensions.
+  if (display->mOverflowX != display->mOverflowY &&
+      (display->mOverflowX == NS_STYLE_OVERFLOW_VISIBLE ||
+       display->mOverflowX == NS_STYLE_OVERFLOW_CLIP ||
+       display->mOverflowY == NS_STYLE_OVERFLOW_VISIBLE ||
+       display->mOverflowY == NS_STYLE_OVERFLOW_CLIP)) {
+    // We can't store in the rule tree since a more specific rule might
+    // change these conditions.
+    inherited = PR_TRUE;
+
+    // NS_STYLE_OVERFLOW_CLIP is a deprecated value, so if it's specified
+    // in only one dimension, convert it to NS_STYLE_OVERFLOW_HIDDEN.
+    if (display->mOverflowX == NS_STYLE_OVERFLOW_CLIP)
+      display->mOverflowX = NS_STYLE_OVERFLOW_HIDDEN;
+    if (display->mOverflowY == NS_STYLE_OVERFLOW_CLIP)
+      display->mOverflowY = NS_STYLE_OVERFLOW_HIDDEN;
+
+    // If 'visible' is specified but doesn't match the other dimension, it
+    // turns into 'auto'.
+    if (display->mOverflowX == NS_STYLE_OVERFLOW_VISIBLE)
+      display->mOverflowX = NS_STYLE_OVERFLOW_AUTO;
+    if (display->mOverflowY == NS_STYLE_OVERFLOW_VISIBLE)
+      display->mOverflowY = NS_STYLE_OVERFLOW_AUTO;
   }
 
   // clip property: length, auto, inherit
diff --git a/mozilla/layout/style/nsStyleStruct.cpp b/mozilla/layout/style/nsStyleStruct.cpp
index fe11994fb64..eb4e27f48c2 100644
--- a/mozilla/layout/style/nsStyleStruct.cpp
+++ b/mozilla/layout/style/nsStyleStruct.cpp
@@ -1102,7 +1102,8 @@ nsStyleDisplay::nsStyleDisplay()
   mBreakType = NS_STYLE_CLEAR_NONE;
   mBreakBefore = PR_FALSE;
   mBreakAfter = PR_FALSE;
-  mOverflow = NS_STYLE_OVERFLOW_VISIBLE;
+  mOverflowX = NS_STYLE_OVERFLOW_VISIBLE;
+  mOverflowY = NS_STYLE_OVERFLOW_VISIBLE;
   mClipFlags = NS_STYLE_CLIP_AUTO;
   mClip.SetRect(0,0,0,0);
   mOpacity = 1.0f;
@@ -1119,7 +1120,8 @@ nsStyleDisplay::nsStyleDisplay(const nsStyleDisplay& aSource)
   mBreakType = aSource.mBreakType;
   mBreakBefore = aSource.mBreakBefore;
   mBreakAfter = aSource.mBreakAfter;
-  mOverflow = aSource.mOverflow;
+  mOverflowX = aSource.mOverflowX;
+  mOverflowY = aSource.mOverflowY;
   mClipFlags = aSource.mClipFlags;
   mClip = aSource.mClip;
   mOpacity = aSource.mOpacity;
@@ -1133,7 +1135,8 @@ nsChangeHint nsStyleDisplay::CalcDifference(const nsStyleDisplay& aOther) const
       || mPosition != aOther.mPosition
       || mDisplay != aOther.mDisplay
       || (mFloats == NS_STYLE_FLOAT_NONE) != (aOther.mFloats == NS_STYLE_FLOAT_NONE)
-      || mOverflow != aOther.mOverflow
+      || mOverflowX != aOther.mOverflowX
+      || mOverflowY != aOther.mOverflowY
       // might need to create a view to handle change from 1.0 to partial opacity
       || (mOpacity != aOther.mOpacity
           && ((mOpacity < 1.0) != (aOther.mOpacity < 1.0))))
diff --git a/mozilla/layout/style/nsStyleStruct.h b/mozilla/layout/style/nsStyleStruct.h
index 305c4e2ec01..4d9fdf026d0 100644
--- a/mozilla/layout/style/nsStyleStruct.h
+++ b/mozilla/layout/style/nsStyleStruct.h
@@ -731,7 +731,8 @@ struct nsStyleDisplay : public nsStyleStruct {
   PRUint8 mBreakType;           // [reset] see nsStyleConsts.h NS_STYLE_CLEAR_*
   PRPackedBool mBreakBefore;    // [reset] 
   PRPackedBool mBreakAfter;     // [reset] 
-  PRUint8   mOverflow;          // [reset] see nsStyleConsts.h
+  PRUint8 mOverflowX;           // [reset] see nsStyleConsts.h
+  PRUint8 mOverflowY;           // [reset] see nsStyleConsts.h
   PRUint8   mClipFlags;         // [reset] see nsStyleConsts.h
   
   PRBool IsBlockLevel() const {return (NS_STYLE_DISPLAY_BLOCK == mDisplay) ||
@@ -747,6 +748,21 @@ struct nsStyleDisplay : public nsStyleStruct {
 
   PRBool IsPositioned() const {return IsAbsolutelyPositioned() ||
                                       (NS_STYLE_POSITION_RELATIVE == mPosition);}
+
+  PRBool IsScrollableOverflow() const {
+    // mOverflowX and mOverflowY always match when one of them is
+    // NS_STYLE_OVERFLOW_VISIBLE or NS_STYLE_OVERFLOW_CLIP.
+    return mOverflowX != NS_STYLE_OVERFLOW_VISIBLE &&
+           mOverflowX != NS_STYLE_OVERFLOW_CLIP;
+  }
+
+  // For table elements that don't support scroll frame creation, we
+  // support 'overflow: hidden' to mean 'overflow: -moz-hidden-unscrollable'.
+  PRBool IsTableClip() const {
+    return mOverflowX == NS_STYLE_OVERFLOW_CLIP ||
+           (mOverflowX == NS_STYLE_OVERFLOW_HIDDEN &&
+            mOverflowY == NS_STYLE_OVERFLOW_HIDDEN);
+  }
 };
 
 struct nsStyleTable: public nsStyleStruct {
diff --git a/mozilla/layout/tables/nsTableCellFrame.cpp b/mozilla/layout/tables/nsTableCellFrame.cpp
index e4c52e98709..8a67f737245 100644
--- a/mozilla/layout/tables/nsTableCellFrame.cpp
+++ b/mozilla/layout/tables/nsTableCellFrame.cpp
@@ -432,10 +432,9 @@ nsTableCellFrame::Paint(nsPresContext*      aPresContext,
                                     nsClipCombine_kIntersect);
     }
     else {
-      if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflow ||
-          // XXXldb HIDDEN should really create a scrollframe,
-          // but test here since it doesn't.
-          NS_STYLE_OVERFLOW_HIDDEN == disp->mOverflow ||
+      // XXXldb HIDDEN should really create a scrollframe,
+      // but use |IsTableClip| here since it doesn't.
+      if (disp->IsTableClip() ||
           HasPctOverHeight()) {
         aRenderingContext.PushState();
         pushed = PR_TRUE;
diff --git a/mozilla/layout/tables/nsTableFrame.cpp b/mozilla/layout/tables/nsTableFrame.cpp
index fe1805c004a..0ce731528d5 100644
--- a/mozilla/layout/tables/nsTableFrame.cpp
+++ b/mozilla/layout/tables/nsTableFrame.cpp
@@ -1360,11 +1360,8 @@ nsTableFrame::PaintChildren(nsPresContext*      aPresContext,
                             const nsRect&        aDirtyRect,
                             nsFramePaintLayer    aWhichLayer,
                             PRUint32             aFlags)
-
 {
-  PRUint8 overflow = GetStyleDisplay()->mOverflow;
-  PRBool clip = overflow == NS_STYLE_OVERFLOW_CLIP ||
-                overflow == NS_STYLE_OVERFLOW_HIDDEN;
+  PRBool clip = GetStyleDisplay()->IsTableClip();
   // If overflow is hidden then set the clip rect so that children don't
   // leak out of us. Note that because overflow'-clip' only applies to
   // the content area we do this after painting the border and background
@@ -2076,7 +2073,7 @@ NS_METHOD nsTableFrame::Reflow(nsPresContext*          aPresContext,
   if (aDesiredSize.mFlags & NS_REFLOW_CALC_MAX_WIDTH) {
     aDesiredSize.mMaximumWidth = GetPreferredWidth();
   }
-  if (NS_STYLE_OVERFLOW_CLIP != aReflowState.mStyleDisplay->mOverflow) {
+  if (!aReflowState.mStyleDisplay->IsTableClip()) {
     // collapsed border may leak out
     nsMargin bcMargin = GetBCMargin(aPresContext);
     nsRect tableRect(0, 0, aDesiredSize.width, aDesiredSize.height) ;
diff --git a/mozilla/layout/tables/nsTableOuterFrame.cpp b/mozilla/layout/tables/nsTableOuterFrame.cpp
index 127772f39a6..e7eb8565e6b 100644
--- a/mozilla/layout/tables/nsTableOuterFrame.cpp
+++ b/mozilla/layout/tables/nsTableOuterFrame.cpp
@@ -333,9 +333,7 @@ nsTableOuterFrame::Paint(nsPresContext*      aPresContext,
   
   // If overflow is hidden then set the clip rect so that children
   // don't leak out of us
-  PRUint8 overflow = GetStyleDisplay()->mOverflow;
-  PRBool clip = overflow == NS_STYLE_OVERFLOW_CLIP ||
-                overflow == NS_STYLE_OVERFLOW_HIDDEN;
+  PRBool clip = GetStyleDisplay()->IsTableClip();
   if (clip) {
     aRenderingContext.PushState();
     SetOverflowClipRect(aRenderingContext);
diff --git a/mozilla/layout/tables/nsTableRowFrame.cpp b/mozilla/layout/tables/nsTableRowFrame.cpp
index ddc21633fbf..3a27edb0afb 100644
--- a/mozilla/layout/tables/nsTableRowFrame.cpp
+++ b/mozilla/layout/tables/nsTableRowFrame.cpp
@@ -555,9 +555,7 @@ NS_METHOD nsTableRowFrame::Paint(nsPresContext*      aPresContext,
     aFlags |= NS_PAINT_FLAG_TABLE_BG_PAINT;
   }
 
-  PRUint8 overflow = GetStyleDisplay()->mOverflow;
-  PRBool clip = overflow == NS_STYLE_OVERFLOW_CLIP ||
-                overflow == NS_STYLE_OVERFLOW_HIDDEN;
+  PRBool clip = GetStyleDisplay()->IsTableClip();
   if (clip) {
     aRenderingContext.PushState();
     SetOverflowClipRect(aRenderingContext);
diff --git a/mozilla/layout/xul/base/src/nsBoxFrame.cpp b/mozilla/layout/xul/base/src/nsBoxFrame.cpp
index 6c39e7bbf54..e2f19886c7b 100644
--- a/mozilla/layout/xul/base/src/nsBoxFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsBoxFrame.cpp
@@ -1630,7 +1630,7 @@ nsBoxFrame::PaintChildren(nsPresContext*      aPresContext,
   
   // If overflow is hidden then set the clip rect so that children
   // don't leak out of us
-  if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflow) {
+  if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflowX) {
     nsMargin im(0,0,0,0);
     GetInset(im);
     r.Deflate(im);
@@ -1643,7 +1643,7 @@ nsBoxFrame::PaintChildren(nsPresContext*      aPresContext,
     nsIFrame* frame = nsnull;
     kid->GetFrame(&frame);
 
-    if (!hasClipped && NS_STYLE_OVERFLOW_CLIP == disp->mOverflow) {
+    if (!hasClipped && NS_STYLE_OVERFLOW_CLIP == disp->mOverflowX) {
         // if we haven't already clipped and we should
         // check to see if the child is in out bounds. If not then
         // we begin clipping.
@@ -1672,7 +1672,7 @@ nsBoxFrame::PaintChildren(nsPresContext*      aPresContext,
     nscoord onePixel = aPresContext->IntScaledPixelsToTwips(1);
     GetContentRect(r);
 
-    if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflow) {
+    if (NS_STYLE_OVERFLOW_CLIP == disp->mOverflowX) {
       GetDebugMargin(debugMargin);
       PixelMarginToTwips(aPresContext, debugMargin);
       r.Deflate(debugMargin);
@@ -1682,7 +1682,7 @@ nsBoxFrame::PaintChildren(nsPresContext*      aPresContext,
 
     GetChildBox(&kid);
     while (nsnull != kid) {
-         if (!hasClipped && NS_STYLE_OVERFLOW_CLIP == disp->mOverflow) {
+         if (!hasClipped && NS_STYLE_OVERFLOW_CLIP == disp->mOverflowX) {
             // if we haven't already clipped and we should
             // check to see if the child is in out bounds. If not then
             // we begin clipping.
diff --git a/mozilla/layout/xul/base/src/nsListBoxBodyFrame.cpp b/mozilla/layout/xul/base/src/nsListBoxBodyFrame.cpp
index bedaceecd9d..343cbbef98e 100644
--- a/mozilla/layout/xul/base/src/nsListBoxBodyFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsListBoxBodyFrame.cpp
@@ -1473,14 +1473,11 @@ nsListboxScrollPortFrame::GetMinSize(nsBoxLayoutState& aBoxLayoutState, nsSize&
   outer->GetContent()->GetAttr(kNameSpaceID_None, nsXULAtoms::sizemode, sizeMode);
   if (!sizeMode.IsEmpty()) {  
     nsCOMPtr<nsIScrollableFrame> scrollFrame(do_QueryInterface(mParent));
-    if (scrollFrame) {
-      nsIScrollableFrame::nsScrollPref scrollPref;
-      scrollFrame->GetScrollPreference(aBoxLayoutState.PresContext(), &scrollPref);
-
-      if (scrollPref == nsIScrollableFrame::Auto) {
-        nsMargin scrollbars = scrollFrame->GetDesiredScrollbarSizes(&aBoxLayoutState);
-        aSize.width += scrollbars.left + scrollbars.right;
-      }
+    if (scrollFrame &&
+        scrollFrame->GetScrollbarStyles().mVertical == NS_STYLE_OVERFLOW_AUTO) {
+      nsMargin scrollbars =
+        scrollFrame->GetDesiredScrollbarSizes(&aBoxLayoutState);
+      aSize.width += scrollbars.left + scrollbars.right;
     }
   }
   else aSize.width = 0;
@@ -1510,14 +1507,10 @@ nsListboxScrollPortFrame::GetPrefSize(nsBoxLayoutState& aBoxLayoutState, nsSize&
     aSize.height = size*outer->GetRowHeightTwips();
    
   nsCOMPtr<nsIScrollableFrame> scrollFrame(do_QueryInterface(mParent));
-  if (scrollFrame) {
-    nsIScrollableFrame::nsScrollPref scrollPref;
-    scrollFrame->GetScrollPreference(aBoxLayoutState.PresContext(), &scrollPref);
-
-    if (scrollPref == nsIScrollableFrame::Auto) {
-      nsMargin scrollbars = scrollFrame->GetDesiredScrollbarSizes(&aBoxLayoutState);
-      aSize.width += scrollbars.left + scrollbars.right;
-    }
+  if (scrollFrame &&
+      scrollFrame->GetScrollbarStyles().mVertical == NS_STYLE_OVERFLOW_AUTO) {
+    nsMargin scrollbars = scrollFrame->GetDesiredScrollbarSizes(&aBoxLayoutState);
+    aSize.width += scrollbars.left + scrollbars.right;
   }
 
   AddMargin(child, aSize);
diff --git a/mozilla/layout/xul/base/src/nsMenuFrame.cpp b/mozilla/layout/xul/base/src/nsMenuFrame.cpp
index 4b843eddce3..16540a561f9 100644
--- a/mozilla/layout/xul/base/src/nsMenuFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsMenuFrame.cpp
@@ -1007,23 +1007,18 @@ nsMenuFrame::DoLayout(nsBoxLayoutState& aState)
     ibox->GetBounds(bounds);
 
     nsCOMPtr<nsIScrollableFrame> scrollframe(do_QueryInterface(child));
-    if (scrollframe) {
-      nsIScrollableFrame::nsScrollPref pref;
-      scrollframe->GetScrollPreference(aState.PresContext(), &pref);
+    if (scrollframe &&
+        scrollframe->GetScrollbarStyles().mVertical == NS_STYLE_OVERFLOW_AUTO) {
+      if (bounds.height < prefSize.height) {
+        // layout the child
+        ibox->Layout(aState);
 
-      if (pref == nsIScrollableFrame::Auto)  
-      {
-        if (bounds.height < prefSize.height) {
-           // layout the child
-           ibox->Layout(aState);
-
-           nsMargin scrollbars = scrollframe->GetActualScrollbarSizes();
-           if (bounds.width < prefSize.width + scrollbars.left + scrollbars.right)
-           {
-             bounds.width += scrollbars.left + scrollbars.right;
-             //printf("Width=%d\n",width);
-             ibox->SetBounds(aState, bounds);
-           }
+        nsMargin scrollbars = scrollframe->GetActualScrollbarSizes();
+        if (bounds.width < prefSize.width + scrollbars.left + scrollbars.right)
+        {
+          bounds.width += scrollbars.left + scrollbars.right;
+          //printf("Width=%d\n",width);
+          ibox->SetBounds(aState, bounds);
         }
       }
     }
diff --git a/mozilla/layout/xul/base/src/nsPopupSetFrame.cpp b/mozilla/layout/xul/base/src/nsPopupSetFrame.cpp
index 6ea75394467..954e8f76a62 100644
--- a/mozilla/layout/xul/base/src/nsPopupSetFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsPopupSetFrame.cpp
@@ -252,24 +252,19 @@ nsPopupSetFrame::DoLayout(nsBoxLayoutState& aState)
       ibox->GetBounds(bounds);
 
       nsCOMPtr<nsIScrollableFrame> scrollframe = do_QueryInterface(child);
-      if (scrollframe) {
-        nsIScrollableFrame::nsScrollPref pref;
-        scrollframe->GetScrollPreference(aState.PresContext(), &pref);
+      if (scrollframe &&
+          scrollframe->GetScrollbarStyles().mVertical == NS_STYLE_OVERFLOW_AUTO) {
+        // if our pref height
+        if (bounds.height < prefSize.height) {
+          // layout the child
+          ibox->Layout(aState);
 
-        if (pref == nsIScrollableFrame::Auto)  
-        {
-          // if our pref height
-          if (bounds.height < prefSize.height) {
-             // layout the child
-             ibox->Layout(aState);
-
-             nsMargin scrollbars = scrollframe->GetActualScrollbarSizes();
-             if (bounds.width < prefSize.width + scrollbars.left + scrollbars.right)
-             {
-               bounds.width += scrollbars.left + scrollbars.right;
-               //printf("Width=%d\n",width);
-               ibox->SetBounds(aState, bounds);
-             }
+          nsMargin scrollbars = scrollframe->GetActualScrollbarSizes();
+          if (bounds.width < prefSize.width + scrollbars.left + scrollbars.right)
+          {
+            bounds.width += scrollbars.left + scrollbars.right;
+            //printf("Width=%d\n",width);
+            ibox->SetBounds(aState, bounds);
           }
         }
       }