diff --git a/mozilla/content/base/src/nsDocument.cpp b/mozilla/content/base/src/nsDocument.cpp
index 290344c761d..0015adaee4a 100644
--- a/mozilla/content/base/src/nsDocument.cpp
+++ b/mozilla/content/base/src/nsDocument.cpp
@@ -2586,7 +2586,9 @@ nsDocument::AddBinding(nsIDOMElement* aContent, const nsAString& aURL)
   GetBindingManager(getter_AddRefs(bm));
   nsCOMPtr<nsIContent> content(do_QueryInterface(aContent));
 
-  return bm->AddLayeredBinding(content, aURL);
+  nsCOMPtr<nsIURI> uri;
+  NS_NewURI(getter_AddRefs(uri), aURL);
+  return bm->AddLayeredBinding(content, uri);
 }
 
 NS_IMETHODIMP
@@ -2599,7 +2601,9 @@ nsDocument::RemoveBinding(nsIDOMElement* aContent, const nsAString& aURL)
 
   if (mBindingManager) {
     nsCOMPtr<nsIContent> content(do_QueryInterface(aContent));
-    return mBindingManager->RemoveLayeredBinding(content, aURL);
+    nsCOMPtr<nsIURI> uri;
+    NS_NewURI(getter_AddRefs(uri), aURL);
+    return mBindingManager->RemoveLayeredBinding(content, uri);
   }
 
   return NS_ERROR_FAILURE;
diff --git a/mozilla/content/base/src/nsRuleNode.cpp b/mozilla/content/base/src/nsRuleNode.cpp
index 61bba67ac11..11d24f40a90 100644
--- a/mozilla/content/base/src/nsRuleNode.cpp
+++ b/mozilla/content/base/src/nsRuleNode.cpp
@@ -2321,7 +2321,7 @@ nsRuleNode::ComputeUserInterfaceData(nsStyleStruct* aStartData,
       ui->mCursor = NS_STYLE_CURSOR_AUTO;
     }
     else if (eCSSUnit_URL == list->mValue.GetUnit()) {
-      list->mValue.GetStringValue(ui->mCursorImage);
+      ui->mCursorImage = list->mValue.GetURLValue();
     }
     else if (eCSSUnit_Inherit == list->mValue.GetUnit()) {
       inherited = PR_TRUE;
@@ -2530,10 +2530,10 @@ nsRuleNode::ComputeDisplayData(nsStyleStruct* aStartStruct,
 
   // binding: url, none, inherit
   if (eCSSUnit_URL == displayData.mBinding.GetUnit()) {
-    displayData.mBinding.GetStringValue(display->mBinding);
+    display->mBinding = displayData.mBinding.GetURLValue();
   }
   else if (eCSSUnit_None == displayData.mBinding.GetUnit()) {
-    display->mBinding.Truncate();
+    display->mBinding = nsnull;
   }
   else if (eCSSUnit_Inherit == displayData.mBinding.GetUnit()) {
     inherited = PR_TRUE;
@@ -2926,11 +2926,11 @@ nsRuleNode::ComputeBackgroundData(nsStyleStruct* aStartStruct,
 
   // background-image: url, none, inherit
   if (eCSSUnit_URL == colorData.mBackImage.GetUnit()) {
-    colorData.mBackImage.GetStringValue(bg->mBackgroundImage);
+    bg->mBackgroundImage = colorData.mBackImage.GetURLValue();
     bg->mBackgroundFlags &= ~NS_STYLE_BG_IMAGE_NONE;
   }
   else if (eCSSUnit_None == colorData.mBackImage.GetUnit()) {
-    bg->mBackgroundImage.Truncate();
+    bg->mBackgroundImage = nsnull;
     bg->mBackgroundFlags |= NS_STYLE_BG_IMAGE_NONE;
   }
   else if (eCSSUnit_Inherit == colorData.mBackImage.GetUnit()) {
@@ -3448,10 +3448,10 @@ nsRuleNode::ComputeListData(nsStyleStruct* aStartStruct,
 
   // list-style-image: url, none, inherit
   if (eCSSUnit_URL == listData.mImage.GetUnit()) {
-    listData.mImage.GetStringValue(list->mListStyleImage);
+    list->mListStyleImage = listData.mImage.GetURLValue();
   }
   else if (eCSSUnit_None == listData.mImage.GetUnit()) {
-    list->mListStyleImage.Truncate();
+    list->mListStyleImage = nsnull;
   }
   else if (eCSSUnit_Inherit == listData.mImage.GetUnit()) {
     inherited = PR_TRUE;
@@ -3813,10 +3813,8 @@ nsRuleNode::ComputeContentData(nsStyleStruct* aStartStruct,
       inherited = PR_TRUE;
       count = parentContent->ContentCount();
       if (NS_SUCCEEDED(content->AllocateContents(count))) {
-        nsStyleContentType type;
         while (0 < count--) {
-          parentContent->GetContentAt(count, type, buffer);
-          content->SetContentAt(count, type, buffer);
+          content->ContentAt(count) = parentContent->ContentAt(count);
         }
       }
     }
@@ -3834,6 +3832,7 @@ nsRuleNode::ComputeContentData(nsStyleStruct* aStartStruct,
           const nsCSSValue& value = contentValue->mValue;
           nsCSSUnit unit = value.GetUnit();
           nsStyleContentType type;
+          nsStyleContentData &data = content->ContentAt(count++);
           switch (unit) {
             case eCSSUnit_String:   type = eStyleContentType_String;    break;
             case eCSSUnit_URL:      type = eStyleContentType_URL;       break;
@@ -3857,13 +3856,18 @@ nsRuleNode::ComputeContentData(nsStyleStruct* aStartStruct,
             default:
               NS_ERROR("bad content type");
           }
-          if (type < eStyleContentType_OpenQuote) {
+          data.mType = type;
+          if (type == eStyleContentType_URL) {
+            data.mContent.mURL = value.GetURLValue();
+            NS_IF_ADDREF(data.mContent.mURL);
+          }
+          else if (type < eStyleContentType_OpenQuote) {
             value.GetStringValue(buffer);
             Unquote(buffer);
-            content->SetContentAt(count++, type, buffer);
+            data.mContent.mString = nsCRT::strdup(buffer.get());
           }
           else {
-            content->SetContentAt(count++, type, nullStr);
+            data.mContent.mString = nsnull;
           }
           contentValue = contentValue->mNext;
         }
diff --git a/mozilla/content/html/content/src/nsGenericHTMLElement.cpp b/mozilla/content/html/content/src/nsGenericHTMLElement.cpp
index a4a6fdf0a76..b335b65bafc 100644
--- a/mozilla/content/html/content/src/nsGenericHTMLElement.cpp
+++ b/mozilla/content/html/content/src/nsGenericHTMLElement.cpp
@@ -3419,7 +3419,6 @@ nsGenericHTMLElement::MapBackgroundAttributesInto(const nsIHTMLMappedAttributes*
     if (NS_CONTENT_ATTR_HAS_VALUE ==
         aAttributes->GetAttribute(nsHTMLAtoms::background, value)) {
       if (eHTMLUnit_String == value.GetUnit()) {
-        nsAutoString absURLSpec;
         nsAutoString spec;
         value.GetStringValue(spec);
         if (!spec.IsEmpty()) {
@@ -3437,10 +3436,11 @@ nsGenericHTMLElement::MapBackgroundAttributesInto(const nsIHTMLMappedAttributes*
               aAttributes->GetAttribute(nsHTMLAtoms::_baseHref, baseHref);
               nsGenericHTMLElement::GetBaseURL(baseHref, doc,
                                                getter_AddRefs(docURL));
-              rv = NS_MakeAbsoluteURI(absURLSpec, spec, docURL);
+              nsCOMPtr<nsIURI> uri;
+              rv = nsContentUtils::NewURIWithDocumentCharset(
+                                       getter_AddRefs(uri), spec, doc, docURL);
               if (NS_SUCCEEDED(rv))
-                aData->mColorData->mBackImage.SetStringValue(absURLSpec,
-                                                             eCSSUnit_URL);
+                aData->mColorData->mBackImage.SetURLValue(uri);
             }
           }
         }
@@ -3451,8 +3451,7 @@ nsGenericHTMLElement::MapBackgroundAttributesInto(const nsIHTMLMappedAttributes*
         aData->mPresContext->GetCompatibilityMode(&mode);
         if (eCompatibility_NavQuirks == mode &&
             eHTMLUnit_Empty == value.GetUnit())
-          aData->mColorData->mBackImage.SetStringValue(NS_LITERAL_STRING(""),
-                                                       eCSSUnit_URL);
+          aData->mColorData->mBackImage.SetNoneValue();
       }
     }
   }
diff --git a/mozilla/content/html/style/src/nsCSSDeclaration.cpp b/mozilla/content/html/style/src/nsCSSDeclaration.cpp
index dcb3c6f3a5d..dd26f79903b 100644
--- a/mozilla/content/html/style/src/nsCSSDeclaration.cpp
+++ b/mozilla/content/html/style/src/nsCSSDeclaration.cpp
@@ -282,8 +282,6 @@ PRBool nsCSSDeclaration::AppendCSSValueToString(nsCSSProperty aProperty, const n
 
   if ((eCSSUnit_String <= unit) && (unit <= eCSSUnit_Counters)) {
     switch (unit) {
-      case eCSSUnit_URL:      aResult.Append(NS_LITERAL_STRING("url("));
-        break;
       case eCSSUnit_Attr:     aResult.Append(NS_LITERAL_STRING("attr("));
         break;
       case eCSSUnit_Counter:  aResult.Append(NS_LITERAL_STRING("counter("));
@@ -385,7 +383,7 @@ PRBool nsCSSDeclaration::AppendCSSValueToString(nsCSSProperty aProperty, const n
       aResult.Append(NS_ConvertASCIItoUCS2(name));
     }
   }
-  else if (eCSSUnit_Color == unit){
+  else if (eCSSUnit_Color == unit) {
     nsAutoString tmpStr;
     nscolor color = aValue.GetColorValue();
 
@@ -406,6 +404,13 @@ PRBool nsCSSDeclaration::AppendCSSValueToString(nsCSSProperty aProperty, const n
 
     aResult.Append(PRUnichar(')'));
   }
+  else if (eCSSUnit_URL == unit) {
+    nsCAutoString spec;
+    aValue.GetURLValue()->GetSpec(spec);
+    aResult.Append(NS_LITERAL_STRING("url(") +
+                   NS_ConvertUTF8toUCS2(spec) +
+                   NS_LITERAL_STRING(")"));
+  }
   else if (eCSSUnit_Percent == unit) {
     nsAutoString tmpStr;
     tmpStr.AppendFloat(aValue.GetPercentValue() * 100.0f);
@@ -426,7 +431,7 @@ PRBool nsCSSDeclaration::AppendCSSValueToString(nsCSSProperty aProperty, const n
     case eCSSUnit_Normal:       aResult.Append(NS_LITERAL_STRING("normal"));   break;
 
     case eCSSUnit_String:       break;
-    case eCSSUnit_URL:
+    case eCSSUnit_URL:          break;
     case eCSSUnit_Attr:
     case eCSSUnit_Counter:
     case eCSSUnit_Counters:     aResult.Append(PRUnichar(')'));    break;
diff --git a/mozilla/content/html/style/src/nsCSSParser.cpp b/mozilla/content/html/style/src/nsCSSParser.cpp
index b1cdffd94c9..b3dba2dacfe 100644
--- a/mozilla/content/html/style/src/nsCSSParser.cpp
+++ b/mozilla/content/html/style/src/nsCSSParser.cpp
@@ -3602,13 +3602,6 @@ PRBool CSSParserImpl::ParseAttr(PRInt32& aErrorCode, nsCSSValue& aValue)
   return PR_FALSE;
 }
 
-inline static PRBool
-css_RequiresAbsoluteURI(const nsString& uri)
-{
-  // cheap shot at figuring out if this requires an absolute url translation
-  return !StringBeginsWith(uri, NS_LITERAL_STRING("chrome:"));
-}
-
 PRBool CSSParserImpl::ParseURL(PRInt32& aErrorCode, nsCSSValue& aValue)
 {
   if (ExpectSymbol(aErrorCode, '(', PR_FALSE)) {
@@ -3620,16 +3613,12 @@ PRBool CSSParserImpl::ParseURL(PRInt32& aErrorCode, nsCSSValue& aValue)
       // Translate url into an absolute url if the url is relative to
       // the style sheet.
       // XXX editors won't like this - too bad for now
-      nsAutoString absURL;
-      nsresult rv = NS_ERROR_FAILURE;
-      if (mURL && css_RequiresAbsoluteURI(tk->mIdent)) {
-        rv = NS_MakeAbsoluteURI(absURL, tk->mIdent, mURL);
-      }
-      if (NS_FAILED(rv)) {
-        absURL = tk->mIdent;
-      }
+      nsCOMPtr<nsIURI> url;
+      NS_NewURI(getter_AddRefs(url), tk->mIdent, nsnull, mURL);
       if (ExpectSymbol(aErrorCode, ')', PR_TRUE)) {
-        aValue.SetStringValue(absURL, eCSSUnit_URL);
+        // Set a null value on failure.  Most failure cases should be
+        // NS_ERROR_MALFORMED_URI.
+        aValue.SetURLValue(url);
         return PR_TRUE;
       }
     }
diff --git a/mozilla/content/html/style/src/nsCSSValue.cpp b/mozilla/content/html/style/src/nsCSSValue.cpp
index bf5e042e2c0..fc2d28c4cf4 100644
--- a/mozilla/content/html/style/src/nsCSSValue.cpp
+++ b/mozilla/content/html/style/src/nsCSSValue.cpp
@@ -90,6 +90,13 @@ nsCSSValue::nsCSSValue(nscolor aValue)
   mValue.mColor = aValue;
 }
 
+nsCSSValue::nsCSSValue(nsIURI* aValue)
+  : mUnit(eCSSUnit_URL)
+{
+  mValue.mURL = aValue;
+  NS_IF_ADDREF(aValue);
+}
+
 nsCSSValue::nsCSSValue(const nsCSSValue& aCopy)
   : mUnit(aCopy.mUnit)
 {
@@ -107,6 +114,10 @@ nsCSSValue::nsCSSValue(const nsCSSValue& aCopy)
   else if (eCSSUnit_Color == mUnit){
     mValue.mColor = aCopy.mValue.mColor;
   }
+  else if (eCSSUnit_URL == mUnit){
+    mValue.mURL = aCopy.mValue.mURL;
+    NS_IF_ADDREF(mValue.mURL);
+  }
   else {
     mValue.mFloat = aCopy.mValue.mFloat;
   }
@@ -127,6 +138,10 @@ nsCSSValue& nsCSSValue::operator=(const nsCSSValue& aCopy)
   else if (eCSSUnit_Color == mUnit){
     mValue.mColor = aCopy.mValue.mColor;
   }
+  else if (eCSSUnit_URL == mUnit){
+    mValue.mURL = aCopy.mValue.mURL;
+    NS_IF_ADDREF(mValue.mURL);
+  }
   else {
     mValue.mFloat = aCopy.mValue.mFloat;
   }
@@ -147,13 +162,20 @@ PRBool nsCSSValue::operator==(const nsCSSValue& aOther) const
       }
     }
     else if ((eCSSUnit_Integer <= mUnit) && (mUnit <= eCSSUnit_Enumerated)) {
-      return PRBool(mValue.mInt == aOther.mValue.mInt);
+      return mValue.mInt == aOther.mValue.mInt;
     }
-    else if (eCSSUnit_Color == mUnit){
-      return PRBool(mValue.mColor == aOther.mValue.mColor);
+    else if (eCSSUnit_Color == mUnit) {
+      return mValue.mColor == aOther.mValue.mColor;
+    }
+    else if (eCSSUnit_URL == mUnit) {
+      PRBool eq;
+      return (mValue.mURL == aOther.mValue.mURL || // handles null == null
+              (mValue.mURL && aOther.mValue.mURL &&
+               NS_SUCCEEDED(mValue.mURL->Equals(aOther.mValue.mURL, &eq)) &&
+               eq));
     }
     else {
-      return PRBool(mValue.mFloat == aOther.mValue.mFloat);
+      return mValue.mFloat == aOther.mValue.mFloat;
     }
   }
   return PR_FALSE;
@@ -189,6 +211,14 @@ void nsCSSValue::SetColorValue(nscolor aValue)
   mValue.mColor = aValue;
 }
 
+void nsCSSValue::SetURLValue(nsIURI* aValue)
+{
+  Reset();
+  mUnit = eCSSUnit_URL;
+  mValue.mURL = aValue;
+  NS_IF_ADDREF(mValue.mURL);
+}
+
 void nsCSSValue::SetAutoValue(void)
 {
   Reset();
@@ -261,7 +291,7 @@ void nsCSSValue::AppendToString(nsAString& aBuffer,
 
     aBuffer.Append(PRUnichar(']'));
   }
-  else if (eCSSUnit_Color == mUnit){
+  else if (eCSSUnit_Color == mUnit) {
     aBuffer.Append(NS_LITERAL_STRING("(0x"));
 
     nsAutoString intStr;
@@ -288,6 +318,15 @@ void nsCSSValue::AppendToString(nsAString& aBuffer,
 
     aBuffer.Append(PRUnichar(')'));
   }
+  else if (eCSSUnit_URL == mUnit) {
+    if (mValue.mURL) {
+      nsCAutoString spec;
+      mValue.mURL->GetSpec(spec);
+      AppendUTF8toUTF16(spec, aBuffer);
+    } else {
+      aBuffer.Append(NS_LITERAL_STRING("url(invalid-url:)"));
+    }
+  }
   else if (eCSSUnit_Percent == mUnit) {
     nsAutoString floatString;
     floatString.AppendFloat(mValue.mFloat * 100.0f);
@@ -351,4 +390,3 @@ void nsCSSValue::ToString(nsAString& aBuffer,
   aBuffer.Truncate();
   AppendToString(aBuffer, aPropID);
 }
-
diff --git a/mozilla/content/html/style/src/nsCSSValue.h b/mozilla/content/html/style/src/nsCSSValue.h
index 1afbf2443d7..3f730eab873 100644
--- a/mozilla/content/html/style/src/nsCSSValue.h
+++ b/mozilla/content/html/style/src/nsCSSValue.h
@@ -44,7 +44,7 @@
 #include "nsCoord.h"
 #include "nsCSSProperty.h"
 #include "nsUnitConversion.h"
-
+#include "nsIURI.h"
 
 enum nsCSSUnit {
   eCSSUnit_Null         = 0,      // (n/a) null unit, value is not specified
@@ -53,11 +53,11 @@ enum nsCSSUnit {
   eCSSUnit_Initial      = 3,      // (n/a) value is default UA value
   eCSSUnit_None         = 4,      // (n/a) value is none
   eCSSUnit_Normal       = 5,      // (n/a) value is normal (algorithmic, different than auto)
-  eCSSUnit_String       = 10,     // (nsString) a string value
-  eCSSUnit_URL          = 11,     // (nsString) a URL value
-  eCSSUnit_Attr         = 12,     // (nsString) a attr(string) value
-  eCSSUnit_Counter      = 13,     // (nsString) a counter(string,[string]) value
-  eCSSUnit_Counters     = 14,     // (nsString) a counters(string,string[,string]) value
+  eCSSUnit_String       = 10,     // (PRUnichar*) a string value
+  eCSSUnit_Attr         = 11,     // (PRUnichar*) a attr(string) value
+  eCSSUnit_Counter      = 12,     // (PRUnichar*) a counter(string,[string]) value
+  eCSSUnit_Counters     = 13,     // (PRUnichar*) a counters(string,string[,string]) value
+  eCSSUnit_URL          = 14,     // (nsIURI*) a URL value (null == invalid URI)
   eCSSUnit_Integer      = 50,     // (int) simple value
   eCSSUnit_Enumerated   = 51,     // (int) value has enumerated meaning
   eCSSUnit_Color        = 80,     // (color) an RGBA value
@@ -129,6 +129,7 @@ public:
   nsCSSValue(float aValue, nsCSSUnit aUnit);
   nsCSSValue(const nsAString& aValue, nsCSSUnit aUnit);
   nsCSSValue(nscolor aValue);
+  nsCSSValue(nsIURI* aValue);
   nsCSSValue(const nsCSSValue& aCopy);
   ~nsCSSValue(void)
   {
@@ -138,7 +139,11 @@ public:
 
   nsCSSValue&  operator=(const nsCSSValue& aCopy);
   PRBool      operator==(const nsCSSValue& aOther) const;
-  PRBool      operator!=(const nsCSSValue& aOther) const;
+
+  PRBool operator!=(const nsCSSValue& aOther) const
+  {
+    return !(*this == aOther);
+  }
 
   nsCSSUnit GetUnit(void) const { return mUnit; };
   PRBool    IsLengthUnit(void) const
@@ -154,11 +159,56 @@ public:
   PRBool    IsTimeUnit(void) const  
     { return PRBool((eCSSUnit_Seconds <= mUnit) && (mUnit <= eCSSUnit_Milliseconds)); }
 
-  PRInt32   GetIntValue(void) const;
-  float     GetPercentValue(void) const;
-  float     GetFloatValue(void) const;
-  nsAString& GetStringValue(nsAString& aBuffer) const;
-  nscolor   GetColorValue(void) const;
+  PRInt32 GetIntValue(void) const
+  {
+    NS_ASSERTION(mUnit == eCSSUnit_Integer || mUnit == eCSSUnit_Enumerated,
+                 "not an int value");
+    return mValue.mInt;
+  }
+
+  float GetPercentValue(void) const
+  {
+    NS_ASSERTION(mUnit == eCSSUnit_Percent, "not a percent value");
+    return mValue.mFloat;
+  }
+
+  float GetFloatValue(void) const
+  {
+    NS_ASSERTION(eCSSUnit_Number <= mUnit, "not a float value");
+    return mValue.mFloat;
+  }
+
+  nsAString& GetStringValue(nsAString& aBuffer) const
+  {
+    NS_ASSERTION(eCSSUnit_String <= mUnit && mUnit <= eCSSUnit_Counters,
+                 "not a string value");
+    aBuffer.Truncate();
+    if (nsnull != mValue.mString) {
+      aBuffer.Append(mValue.mString);
+    }
+    return aBuffer;
+  }
+
+  const PRUnichar* GetStringBufferValue() const
+  {
+    NS_ASSERTION(eCSSUnit_String <= mUnit && mUnit <= eCSSUnit_Counters,
+                 "not a string value");
+    return mValue.mString;
+  }
+
+  nscolor GetColorValue(void) const
+  {
+    NS_ASSERTION((mUnit == eCSSUnit_Color), "not a color value");
+    return mValue.mColor;
+  }
+
+  nsIURI* GetURLValue(void) const
+  {
+    NS_ASSERTION(mUnit == eCSSUnit_URL, "not a URL value");
+    return mValue.mURL;
+  }
+
+
   nscoord   GetLengthTwips(void) const
   {
     NS_ASSERTION(IsFixedLengthUnit(), "not a fixed length unit");
@@ -202,6 +252,8 @@ public:
     if ((eCSSUnit_String <= mUnit) && (mUnit <= eCSSUnit_Counters) &&
         (nsnull != mValue.mString)) {
       nsCRT::free(mValue.mString);
+    } else if (eCSSUnit_URL == mUnit) {
+      NS_IF_RELEASE(mValue.mURL);
     }
     mUnit = eCSSUnit_Null;
     mValue.mInt = 0;
@@ -227,6 +279,7 @@ public:
 
   void  SetStringValue(const nsAString& aValue, nsCSSUnit aUnit);
   void  SetColorValue(nscolor aValue);
+  void  SetURLValue(nsIURI* aURI);
   void  SetAutoValue(void);
   void  SetInheritValue(void);
   void  SetInitialValue(void);
@@ -234,6 +287,7 @@ public:
   void  SetNormalValue(void);
 
   // debugging methods only
+  // XXXldb Not anymore!
   void  AppendToString(nsAString& aBuffer, nsCSSProperty aPropID = eCSSProperty_UNKNOWN) const;
   void  ToString(nsAString& aBuffer, nsCSSProperty aPropID = eCSSProperty_UNKNOWN) const;
 
@@ -244,64 +298,9 @@ protected:
     float      mFloat;
     PRUnichar* mString;
     nscolor    mColor;
+    nsIURI*    mURL;
   }         mValue;
 };
 
-inline PRInt32 nsCSSValue::GetIntValue(void) const
-{
-  NS_ASSERTION((mUnit == eCSSUnit_Integer) ||
-               (mUnit == eCSSUnit_Enumerated), "not an int value");
-  if ((mUnit == eCSSUnit_Integer) ||
-      (mUnit == eCSSUnit_Enumerated)) {
-    return mValue.mInt;
-  }
-  return 0;
-}
-
-inline float nsCSSValue::GetPercentValue(void) const
-{
-  NS_ASSERTION((mUnit == eCSSUnit_Percent), "not a percent value");
-  if ((mUnit == eCSSUnit_Percent)) {
-    return mValue.mFloat;
-  }
-  return 0.0f;
-}
-
-inline float nsCSSValue::GetFloatValue(void) const
-{
-  NS_ASSERTION((eCSSUnit_Number <= mUnit), "not a float value");
-  if ((mUnit >= eCSSUnit_Number)) {
-    return mValue.mFloat;
-  }
-  return 0.0f;
-}
-
-inline nsAString& nsCSSValue::GetStringValue(nsAString& aBuffer) const
-{
-  NS_ASSERTION((eCSSUnit_String <= mUnit) && (mUnit <= eCSSUnit_Counters), "not a string value");
-  aBuffer.Truncate();
-  if ((eCSSUnit_String <= mUnit) && (mUnit <= eCSSUnit_Counters) && 
-      (nsnull != mValue.mString)) {
-    aBuffer.Append(mValue.mString);
-  }
-  return aBuffer;
-}
-
-inline nscolor nsCSSValue::GetColorValue(void) const
-{
-  NS_ASSERTION((mUnit == eCSSUnit_Color), "not a color value");
-  if (mUnit == eCSSUnit_Color) {
-    return mValue.mColor;
-  }
-  return NS_RGB(0,0,0);
-}
-
-inline PRBool nsCSSValue::operator!=(const nsCSSValue& aOther) const
-{
-  return PRBool(! ((*this) == aOther));
-}
-
-
-
 #endif /* nsCSSValue_h___ */
 
diff --git a/mozilla/content/html/style/src/nsComputedDOMStyle.cpp b/mozilla/content/html/style/src/nsComputedDOMStyle.cpp
index 7113e1befee..0d728a9a73b 100644
--- a/mozilla/content/html/style/src/nsComputedDOMStyle.cpp
+++ b/mozilla/content/html/style/src/nsComputedDOMStyle.cpp
@@ -339,7 +339,7 @@ nsComputedDOMStyle::GetBinding(nsIFrame *aFrame,
 
   GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display, aFrame);
 
-  if (display && !display->mBinding.IsEmpty()) {
+  if (display && display->mBinding) {
     val->SetURI(display->mBinding);
   } else {
     val->SetIdent(NS_LITERAL_STRING("none"));
@@ -1307,7 +1307,7 @@ nsComputedDOMStyle::GetListStyleImage(nsIFrame *aFrame,
   GetStyleData(eStyleStruct_List, (const nsStyleStruct*&)list, aFrame);
 
   if (list) {
-    if (list->mListStyleImage.IsEmpty()) {
+    if (!list->mListStyleImage) {
       val->SetIdent(NS_LITERAL_STRING("none"));
     } else {
       val->SetURI(list->mListStyleImage);
@@ -1741,7 +1741,7 @@ nsComputedDOMStyle::GetCursor(nsIFrame *aFrame,
   GetStyleData(eStyleStruct_UserInterface, (const nsStyleStruct*&)ui, aFrame);
 
   if (ui) {
-    if (!ui->mCursorImage.IsEmpty()) {
+    if (ui->mCursorImage) {
       val->SetURI(ui->mCursorImage);
     } else {
       if (ui->mCursor == NS_STYLE_CURSOR_AUTO) {
diff --git a/mozilla/content/html/style/src/nsROCSSPrimitiveValue.cpp b/mozilla/content/html/style/src/nsROCSSPrimitiveValue.cpp
index 75a1b521a10..6c1c1ace849 100644
--- a/mozilla/content/html/style/src/nsROCSSPrimitiveValue.cpp
+++ b/mozilla/content/html/style/src/nsROCSSPrimitiveValue.cpp
@@ -58,16 +58,20 @@ nsROCSSPrimitiveValue::~nsROCSSPrimitiveValue()
 }
 
 void
-nsROCSSPrimitiveValue::GetEscapedURI(PRUnichar *aURI, PRUnichar **aReturn)
+nsROCSSPrimitiveValue::GetEscapedURI(nsIURI *aURI, PRUnichar **aReturn)
 {
-  PRUint16 length = nsCRT::strlen(aURI);
+  nsCAutoString specUTF8;
+  aURI->GetSpec(specUTF8);
+  NS_ConvertUTF8toUCS2 spec(specUTF8);
+
+  PRUint16 length = spec.Length();
   PRUnichar *escaped = (PRUnichar *)nsMemory::Alloc(length * 2 * sizeof(PRUnichar) + sizeof(PRUnichar('\0')));
 
   if (escaped) {
     PRUnichar *ptr = escaped;
 
     for (PRUint16 i = 0; i < length; ++i) {
-      switch (aURI[i]) {
+      switch (spec[i]) {
         case ' ' : // space
         case '\t': // tab
         case '(' : // opening parenthesis
@@ -83,7 +87,7 @@ nsROCSSPrimitiveValue::GetEscapedURI(PRUnichar *aURI, PRUnichar **aReturn)
         default:
           break;
       }
-      *ptr++ = aURI[i];
+      *ptr++ = spec[i];
     }
     *ptr = 0;
   }
@@ -159,10 +163,16 @@ nsROCSSPrimitiveValue::GetCssText(nsAString& aCssText)
     case CSS_URI :
       {
         nsXPIDLString uri;
-        GetEscapedURI(mValue.mString, getter_Copies(uri));
-        tmpStr.Assign(NS_LITERAL_STRING("url(") +
-                      uri +
-                      NS_LITERAL_STRING(")"));
+        if (mValue.mURI) {
+          GetEscapedURI(mValue.mURI, getter_Copies(uri));
+          tmpStr.Assign(NS_LITERAL_STRING("url(") +
+                        uri +
+                        NS_LITERAL_STRING(")"));
+        } else {
+          // XXXldb Any better ideas?  It's good to have something that
+          // doesn't parse so that things round-trip "correctly".
+          tmpStr.Assign(NS_LITERAL_STRING("url(invalid-url:)"));
+        }
         break;
       }
     case CSS_PERCENTAGE :
@@ -401,9 +411,14 @@ nsROCSSPrimitiveValue::GetStringValue(nsAString& aReturn)
   switch (mType) {
     case CSS_IDENT:
     case CSS_STRING:
-    case CSS_URI:
       aReturn.Assign(mValue.mString);
       break;
+    case CSS_URI: {
+      nsCAutoString spec;
+      if (mValue.mURI)
+        mValue.mURI->GetSpec(spec);
+      CopyUTF8toUTF16(spec, aReturn);
+      } break;
     case CSS_ATTR:
     default:
       aReturn.Truncate();
diff --git a/mozilla/content/html/style/src/nsROCSSPrimitiveValue.h b/mozilla/content/html/style/src/nsROCSSPrimitiveValue.h
index b7f47a9caa8..d46528621f4 100644
--- a/mozilla/content/html/style/src/nsROCSSPrimitiveValue.h
+++ b/mozilla/content/html/style/src/nsROCSSPrimitiveValue.h
@@ -44,6 +44,7 @@
 #include "nsCoord.h"
 #include "nsUnitConversion.h"
 #include "nsReadableUtils.h"
+#include "nsIURI.h"
 
 #include "nsCOMPtr.h"
 #include "nsDOMError.h"
@@ -151,26 +152,12 @@ public:
     }
   }
 
-  void SetURI(const nsACString& aString)
+  void SetURI(nsIURI *aURI)
   {
     Reset();
-    mValue.mString = ToNewUnicode(aString);
-    if (mValue.mString) {
-      mType = CSS_URI;
-    } else {
-      mType = CSS_UNKNOWN;
-    }
-  }
-
-  void SetURI(const nsAString& aString)
-  {
-    Reset();
-    mValue.mString = ToNewUnicode(aString);
-    if (mValue.mString) {
-      mType = CSS_URI;
-    } else {
-      mType = CSS_UNKNOWN;
-    }
+    mValue.mURI = aURI;
+    NS_IF_ADDREF(mValue.mURI);
+    mType = CSS_URI;
   }
 
   void SetColor(nsIDOMRGBColor* aColor)
@@ -206,11 +193,13 @@ public:
     switch (mType) {
       case CSS_IDENT:
       case CSS_STRING:
-      case CSS_URI:
         NS_ASSERTION(mValue.mString, "Null string should never happen");
         nsMemory::Free(mValue.mString);
         mValue.mString = nsnull;
         break;
+      case CSS_URI:
+        NS_IF_RELEASE(mValue.mURI);
+        break;
       case CSS_RECT:
         NS_ASSERTION(mValue.mRect, "Null Rect should never happen");
         NS_RELEASE(mValue.mRect);
@@ -225,7 +214,7 @@ public:
   }
 
 private:
-  void GetEscapedURI(PRUnichar *aURI, PRUnichar **aReturn);
+  void GetEscapedURI(nsIURI *aURI, PRUnichar **aReturn);
 
   PRUint16 mType;
 
@@ -235,6 +224,7 @@ private:
     nsIDOMRGBColor* mColor;
     nsIDOMRect*     mRect;
     PRUnichar*      mString;
+    nsIURI*         mURI;
   } mValue;
   
   float mT2P;
diff --git a/mozilla/content/shared/public/nsStyleStruct.h b/mozilla/content/shared/public/nsStyleStruct.h
index 34381e87c16..c10c15bc946 100644
--- a/mozilla/content/shared/public/nsStyleStruct.h
+++ b/mozilla/content/shared/public/nsStyleStruct.h
@@ -52,6 +52,7 @@
 #include "nsIPresShell.h"
 #include "nsCOMPtr.h"
 #include "nsILanguageAtom.h"
+#include "nsIURI.h"
 
 class nsIFrame;
 
@@ -183,7 +184,7 @@ struct nsStyleBackground : public nsStyleStruct {
     mBackgroundYPosition;         // [reset]
 
   nscolor mBackgroundColor;       // [reset]
-  nsString mBackgroundImage;      // [reset] absolute url string
+  nsCOMPtr<nsIURI> mBackgroundImage; // [reset]
 
   PRBool IsTransparent() const
   {
@@ -586,7 +587,7 @@ struct nsStyleList : public nsStyleStruct {
   
   PRUint8   mListStyleType;             // [inherited] See nsStyleConsts.h
   PRUint8   mListStylePosition;         // [inherited] 
-  nsString  mListStyleImage;            // [inherited] absolute url string
+  nsCOMPtr<nsIURI> mListStyleImage;     // [inherited]
   nsRect        mImageRegion;           // [inherited] the rect to use within an image  
 };
 
@@ -732,7 +733,7 @@ struct nsStyleDisplay : public nsStyleStruct {
 
   nsChangeHint CalcDifference(const nsStyleDisplay& aOther) const;
   
-  nsString  mBinding;           // [reset] absolute url string
+  nsCOMPtr<nsIURI> mBinding;    // [reset]
 #if 0
   // XXX This is how it is defined in the CSS2 spec, but the errata
   // changed it to be consistent with the positioning draft and how
@@ -834,7 +835,48 @@ enum nsStyleContentType {
 
 struct nsStyleContentData {
   nsStyleContentType  mType;
-  nsString            mContent;
+  union {
+    PRUnichar *mString;
+    nsIURI    *mURL;
+  } mContent;
+
+  ~nsStyleContentData() {
+    if (mType == eStyleContentType_URL) {
+      NS_IF_RELEASE(mContent.mURL);
+    } else if (mContent.mString) {
+      nsCRT::free(mContent.mString);
+    }
+  }
+
+  nsStyleContentData& operator=(const nsStyleContentData& aOther) {
+    mType = aOther.mType;
+    if (mType == eStyleContentType_URL) {
+      mContent.mURL = aOther.mContent.mURL;
+      NS_IF_ADDREF(mContent.mURL);
+    } else if (aOther.mContent.mString) {
+      mContent.mString = nsCRT::strdup(aOther.mContent.mString);
+    } else {
+      mContent.mString = nsnull;
+    }
+    return *this;
+  }
+
+  PRBool operator==(const nsStyleContentData& aOther) {
+    if (mType != aOther.mType)
+      return PR_FALSE;
+    if (mType == eStyleContentType_URL) {
+      PRBool eq;
+      return mContent.mURL == aOther.mContent.mURL ||  // handles null==null
+             (mContent.mURL && aOther.mContent.mURL &&
+              NS_SUCCEEDED(mContent.mURL->Equals(aOther.mContent.mURL, &eq)) &&
+              eq);
+    }
+    return mContent.mString == aOther.mContent.mString;
+  }
+
+  PRBool operator!=(const nsStyleContentData& aOther) {
+    return !(*this == aOther);
+  }
 };
 
 struct nsStyleCounterData {
@@ -926,13 +968,15 @@ struct nsStyleContent: public nsStyleStruct {
   nsChangeHint CalcDifference(const nsStyleContent& aOther) const;
 
   PRUint32  ContentCount(void) const  { return mContentCount; } // [reset]
-  nsresult  GetContentAt(PRUint32 aIndex, nsStyleContentType& aType, nsString& aContent) const {
-    if (aIndex < mContentCount) {
-      aType = mContents[aIndex].mType;
-      aContent = mContents[aIndex].mContent;
-      return NS_OK;
-    }
-    return NS_ERROR_ILLEGAL_VALUE;
+
+  const nsStyleContentData& ContentAt(PRUint32 aIndex) const {
+    NS_ASSERTION(aIndex < mContentCount, "out of range");
+    return mContents[aIndex];
+  }
+
+  nsStyleContentData& ContentAt(PRUint32 aIndex) {
+    NS_ASSERTION(aIndex < mContentCount, "out of range");
+    return mContents[aIndex];
   }
 
   nsresult  AllocateContents(PRUint32 aCount) {
@@ -950,20 +994,6 @@ struct nsStyleContent: public nsStyleStruct {
     return NS_OK;
   }
 
-  nsresult  SetContentAt(PRUint32 aIndex, nsStyleContentType aType, const nsString& aContent) {
-    if (aIndex < mContentCount) {
-      mContents[aIndex].mType = aType;
-      if (aType < eStyleContentType_OpenQuote) {
-        mContents[aIndex].mContent = aContent;
-      }
-      else {
-        mContents[aIndex].mContent.Truncate();
-      }
-      return NS_OK;
-    }
-    return NS_ERROR_ILLEGAL_VALUE;
-  }
-
   PRUint32  CounterIncrementCount(void) const { return mIncrementCount; }  // [reset]
   nsresult  GetCounterIncrementAt(PRUint32 aIndex, nsString& aCounter, PRInt32& aIncrement) const {
     if (aIndex < mIncrementCount) {
@@ -1094,7 +1124,7 @@ struct nsStyleUserInterface: public nsStyleStruct {
   PRUint8   mUserFocus;       // [inherited] (auto-select)
   
   PRUint8 mCursor;                // [inherited] See nsStyleConsts.h NS_STYLE_CURSOR_*
-  nsString mCursorImage;          // [inherited] url string
+  nsCOMPtr<nsIURI> mCursorImage; // [inherited] url string
 };
 
 struct nsStyleXUL : public nsStyleStruct {
diff --git a/mozilla/content/shared/src/nsStyleStruct.cpp b/mozilla/content/shared/src/nsStyleStruct.cpp
index f6886c08c89..a4b9438d1e6 100644
--- a/mozilla/content/shared/src/nsStyleStruct.cpp
+++ b/mozilla/content/shared/src/nsStyleStruct.cpp
@@ -701,7 +701,6 @@ nsStyleList::nsStyleList()
 {
   mListStyleType = NS_STYLE_LIST_STYLE_BASIC;
   mListStylePosition = NS_STYLE_LIST_STYLE_POSITION_OUTSIDE;
-  mListStyleImage.Truncate();  
 }
 
 nsStyleList::~nsStyleList() 
@@ -709,10 +708,10 @@ nsStyleList::~nsStyleList()
 }
 
 nsStyleList::nsStyleList(const nsStyleList& aSource)
+  : mListStyleType(aSource.mListStyleType),
+    mListStylePosition(aSource.mListStylePosition),
+    mListStyleImage(aSource.mListStyleImage)
 {
-  mListStyleType = aSource.mListStyleType;
-  mListStylePosition = aSource.mListStylePosition;
-  mListStyleImage = aSource.mListStyleImage;
 }
 
 nsChangeHint nsStyleList::CalcDifference(const nsStyleList& aOther) const
@@ -1192,7 +1191,7 @@ nsStyleContent::nsStyleContent(const nsStyleContent& aSource)
   PRUint32 index;
   if (NS_SUCCEEDED(AllocateContents(aSource.ContentCount()))) {
     for (index = 0; index < mContentCount; index++) {
-      aSource.GetContentAt(index, mContents[index].mType, mContents[index].mContent);
+      ContentAt(index) = aSource.ContentAt(index);
     }
   }
 
@@ -1219,8 +1218,7 @@ nsChangeHint nsStyleContent::CalcDifference(const nsStyleContent& aOther) const
         (mResetCount == aOther.mResetCount)) {
       PRUint32 ix = mContentCount;
       while (0 < ix--) {
-        if ((mContents[ix].mType != aOther.mContents[ix].mType) || 
-            (mContents[ix].mContent != aOther.mContents[ix].mContent)) {
+        if (mContents[ix] != aOther.mContents[ix]) {
           // Unfortunately we need to reframe here; a simple reflow
           // will not pick up different text or different image URLs,
           // since we set all that up in the CSSFrameConstructor
diff --git a/mozilla/content/xbl/public/nsIBindingManager.h b/mozilla/content/xbl/public/nsIBindingManager.h
index 925bbd8a6d0..1967ac1f894 100644
--- a/mozilla/content/xbl/public/nsIBindingManager.h
+++ b/mozilla/content/xbl/public/nsIBindingManager.h
@@ -54,6 +54,7 @@ class nsIXBLBinding;
 class nsIXBLDocumentInfo;
 class nsIAtom;
 class nsIStreamListener;
+class nsIURI;
 class nsIXPConnectWrappedJS;
 class nsIDOMNodeList;
 class nsVoidArray;
@@ -150,8 +151,8 @@ public:
   NS_IMETHOD GetSingleInsertionPoint(nsIContent* aParent, nsIContent** aResult, PRUint32* aIndex,  
                                      PRBool* aMultipleInsertionPoints) = 0;
 
-  NS_IMETHOD AddLayeredBinding(nsIContent* aContent, const nsAString& aURL) = 0;
-  NS_IMETHOD RemoveLayeredBinding(nsIContent* aContent, const nsAString& aURL) = 0;
+  NS_IMETHOD AddLayeredBinding(nsIContent* aContent, nsIURI* aURL) = 0;
+  NS_IMETHOD RemoveLayeredBinding(nsIContent* aContent, nsIURI* aURL) = 0;
   NS_IMETHOD LoadBindingDocument(nsIDocument* aDocument, const nsAString& aURL,
                                  nsIDocument** aResult) = 0;
 
diff --git a/mozilla/content/xbl/public/nsIXBLService.h b/mozilla/content/xbl/public/nsIXBLService.h
index 326dcad7ed6..4dd1297ffdf 100644
--- a/mozilla/content/xbl/public/nsIXBLService.h
+++ b/mozilla/content/xbl/public/nsIXBLService.h
@@ -69,7 +69,7 @@ public:
 
   // This function loads a particular XBL file and installs all of the bindings
   // onto the element.
-  NS_IMETHOD LoadBindings(nsIContent* aContent, const nsAString& aURL, PRBool aAugmentFlag,
+  NS_IMETHOD LoadBindings(nsIContent* aContent, nsIURI* aURL, PRBool aAugmentFlag,
                           nsIXBLBinding** aBinding, PRBool* aResolveStyle) = 0;
 
   // Indicates whether or not a binding is fully loaded.
diff --git a/mozilla/content/xbl/src/nsBindingManager.cpp b/mozilla/content/xbl/src/nsBindingManager.cpp
index 86b046ec9a3..c1f919dd65a 100644
--- a/mozilla/content/xbl/src/nsBindingManager.cpp
+++ b/mozilla/content/xbl/src/nsBindingManager.cpp
@@ -352,8 +352,8 @@ public:
   NS_IMETHOD GetSingleInsertionPoint(nsIContent* aParent, nsIContent** aResult, PRUint32* aIndex,  
                                      PRBool* aMultipleInsertionPoints);
 
-  NS_IMETHOD AddLayeredBinding(nsIContent* aContent, const nsAString& aURL);
-  NS_IMETHOD RemoveLayeredBinding(nsIContent* aContent, const nsAString& aURL);
+  NS_IMETHOD AddLayeredBinding(nsIContent* aContent, nsIURI* aURL);
+  NS_IMETHOD RemoveLayeredBinding(nsIContent* aContent, nsIURI* aURL);
   NS_IMETHOD LoadBindingDocument(nsIDocument* aBoundDoc, const nsAString& aURL,
                                  nsIDocument** aResult);
 
@@ -801,7 +801,7 @@ nsBindingManager::GetSingleInsertionPoint(nsIContent* aParent, nsIContent** aRes
 }
 
 NS_IMETHODIMP
-nsBindingManager::AddLayeredBinding(nsIContent* aContent, const nsAString& aURL)
+nsBindingManager::AddLayeredBinding(nsIContent* aContent, nsIURI* aURL)
 {
   // First we need to load our binding.
   nsresult rv;
@@ -823,7 +823,7 @@ nsBindingManager::AddLayeredBinding(nsIContent* aContent, const nsAString& aURL)
 }
 
 NS_IMETHODIMP
-nsBindingManager::RemoveLayeredBinding(nsIContent* aContent, const nsAString& aURL)
+nsBindingManager::RemoveLayeredBinding(nsIContent* aContent, nsIURI* aURL)
 {
   nsCOMPtr<nsIXBLBinding> binding;
   GetBinding(aContent, getter_AddRefs(binding));
@@ -844,11 +844,8 @@ nsBindingManager::RemoveLayeredBinding(nsIContent* aContent, const nsAString& aU
   nsresult rv = NS_NewURI(getter_AddRefs(bindingUri), bindingUriStr);
   NS_ENSURE_SUCCESS(rv, rv);
   
-  nsCOMPtr<nsIURI> uri;
-  rv = NS_NewURI(getter_AddRefs(uri), aURL);
-  NS_ENSURE_SUCCESS(rv, rv);
   PRBool equalUri;
-  rv = uri->Equals(bindingUri, &equalUri);
+  rv = aURL->Equals(bindingUri, &equalUri);
   NS_ENSURE_SUCCESS(rv, rv);
   if (!equalUri) {
     return NS_OK;
diff --git a/mozilla/content/xbl/src/nsXBLService.cpp b/mozilla/content/xbl/src/nsXBLService.cpp
index 7f6709d86b9..b5f44fd3d97 100644
--- a/mozilla/content/xbl/src/nsXBLService.cpp
+++ b/mozilla/content/xbl/src/nsXBLService.cpp
@@ -528,7 +528,7 @@ nsXBLService::~nsXBLService(void)
 // This function loads a particular XBL file and installs all of the bindings
 // onto the element.
 NS_IMETHODIMP
-nsXBLService::LoadBindings(nsIContent* aContent, const nsAString& aURL, PRBool aAugmentFlag,
+nsXBLService::LoadBindings(nsIContent* aContent, nsIURI* aURL, PRBool aAugmentFlag,
                            nsIXBLBinding** aBinding, PRBool* aResolveStyle) 
 { 
   *aBinding = nsnull;
@@ -559,14 +559,16 @@ nsXBLService::LoadBindings(nsIContent* aContent, const nsAString& aURL, PRBool a
       }
       else {
         // See if the URIs match.
-        nsCAutoString uri;
-        styleBinding->GetBindingURI(uri);
-        if (uri.Equals(NS_ConvertUCS2toUTF8(aURL)))
+        nsCAutoString spec;
+        styleBinding->GetBindingURI(spec);
+        nsCOMPtr<nsIURI> uri;
+        // XXX This needs an origin charset.
+        NS_NewURI(getter_AddRefs(uri), spec.get());
+        PRBool equal;
+        if (NS_SUCCEEDED(uri->Equals(aURL, &equal)) && equal)
           return NS_OK;
-        else {
-          FlushStyleBindings(aContent);
-          binding = nsnull;
-        }
+        FlushStyleBindings(aContent);
+        binding = nsnull;
       }
     }
   }
@@ -579,29 +581,29 @@ nsXBLService::LoadBindings(nsIContent* aContent, const nsAString& aURL, PRBool a
   rv = docURI->SchemeIs("chrome", &isChrome);
 
   if (NS_FAILED(rv) || !isChrome) {
-    nsCOMPtr<nsIURI> bindingURI;
-    rv = NS_NewURI(getter_AddRefs(bindingURI), aURL);
-    NS_ENSURE_SUCCESS(rv, rv);
-
     nsCOMPtr<nsIScriptSecurityManager> secMan(
       do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID, &rv));
     NS_ENSURE_SUCCESS(rv, rv);
 
-    rv = secMan->CheckLoadURI(docURI, bindingURI,
+    rv = secMan->CheckLoadURI(docURI, aURL,
                               nsIScriptSecurityManager::ALLOW_CHROME);
     if (NS_FAILED(rv))
       return rv;
   }
   nsCOMPtr<nsIXBLBinding> newBinding;
-  nsCAutoString url; url.AssignWithConversion(aURL);
-  if (NS_FAILED(rv = GetBinding(aContent, url, getter_AddRefs(newBinding)))) {
+  nsCAutoString spec;
+  aURL->GetSpec(spec);
+  if (NS_FAILED(rv = GetBinding(aContent, spec, getter_AddRefs(newBinding)))) {
     return rv;
   }
 
   if (!newBinding) {
-    nsCAutoString str( "Failed to locate XBL binding. XBL is now using id instead of name to reference bindings. Make sure you have switched over.  The invalid binding name is: ");
-    str.AppendWithConversion(aURL);
+#ifdef DEBUG
+    nsCAutoString spec;
+    aURL->GetSpec(spec);
+    nsCAutoString str(NS_LITERAL_CSTRING("Failed to locate XBL binding. XBL is now using id instead of name to reference bindings. Make sure you have switched over.  The invalid binding name is: ") + spec);
     NS_ERROR(str.get());
+#endif
     return NS_OK;
   }
 
diff --git a/mozilla/content/xbl/src/nsXBLService.h b/mozilla/content/xbl/src/nsXBLService.h
index e719e9f629b..5813a75c425 100644
--- a/mozilla/content/xbl/src/nsXBLService.h
+++ b/mozilla/content/xbl/src/nsXBLService.h
@@ -67,7 +67,7 @@ class nsXBLService : public nsIXBLService,
 
   // This function loads a particular XBL file and installs all of the bindings
   // onto the element.
-  NS_IMETHOD LoadBindings(nsIContent* aContent, const nsAString& aURL, PRBool aAugmentFlag,
+  NS_IMETHOD LoadBindings(nsIContent* aContent, nsIURI* aURL, PRBool aAugmentFlag,
                           nsIXBLBinding** aBinding, PRBool* aResolveStyle);
 
   // Indicates whether or not a binding is fully loaded.
diff --git a/mozilla/dom/src/base/nsDOMClassInfo.cpp b/mozilla/dom/src/base/nsDOMClassInfo.cpp
index 35a077b7d4f..2c31dbba713 100644
--- a/mozilla/dom/src/base/nsDOMClassInfo.cpp
+++ b/mozilla/dom/src/base/nsDOMClassInfo.cpp
@@ -4661,9 +4661,9 @@ nsElementSH::PostCreate(nsIXPConnectWrappedNative *wrapper, JSContext *cx,
   // the DOM computed style API.  We can get rid of this hack if we merge
   // the jsdom library with layout.
 
-  nsAutoString bindingURL;
-  pctx->GetXBLBindingURL(content, bindingURL);
-  if (bindingURL.IsEmpty()) {
+  nsCOMPtr<nsIURI> bindingURL;
+  pctx->GetXBLBindingURL(content, getter_AddRefs(bindingURL));
+  if (!binding) {
     // No binding, nothing left to do here.
     return NS_OK;
   }
diff --git a/mozilla/embedding/browser/webBrowser/nsContextMenuInfo.cpp b/mozilla/embedding/browser/webBrowser/nsContextMenuInfo.cpp
index 0f29e0ae82e..e6ffb21c685 100644
--- a/mozilla/embedding/browser/webBrowser/nsContextMenuInfo.cpp
+++ b/mozilla/embedding/browser/webBrowser/nsContextMenuInfo.cpp
@@ -269,9 +269,9 @@ nsContextMenuInfo::GetBackgroundImageRequest(nsIDOMNode * aDOMNode, imgIRequest
     do {
       bg = frame->GetStyleBackground();
       frame = frame->GetParent();
-    } while (bg && bg->mBackgroundImage.IsEmpty() && frame);
+    } while (!bg->mBackgroundImage && frame);
      
-    if (bg && !bg->mBackgroundImage.IsEmpty())
+    if (bg->mBackgroundImage)
     {
       nsIFrame *pBGFrame = nsnull;
       rv = GetFrameForBackgroundUpdate(presContext, frame, &pBGFrame);
@@ -304,7 +304,7 @@ nsContextMenuInfo::GetBackgroundImageRequest(nsIDOMNode * aDOMNode, imgIRequest
     PRBool isCanvas;
     PRBool foundBackground;
     presContext->FindFrameBackground(frame, &bg, &isCanvas, &foundBackground);
-    if (bg && !bg->mBackgroundImage.IsEmpty())
+    if (bg && bg->mBackgroundImage)
     {
       nsIFrame *pBGFrame = nsnull;
       rv = GetFrameForBackgroundUpdate(presContext, frame, &pBGFrame);
diff --git a/mozilla/extensions/inspector/base/src/inCSSValueSearch.cpp b/mozilla/extensions/inspector/base/src/inCSSValueSearch.cpp
index 2a7bfe8988c..6c39e143195 100644
--- a/mozilla/extensions/inspector/base/src/inCSSValueSearch.cpp
+++ b/mozilla/extensions/inspector/base/src/inCSSValueSearch.cpp
@@ -332,12 +332,16 @@ inCSSValueSearch::SearchStyleValue(nsICSSStyleRule* aRule, nsCSSProperty aProp)
   aRule->GetValue(aProp, value);
 
   if (value.GetUnit() == eCSSUnit_URL) {
-    nsAutoString* result = new nsAutoString();
-    value.GetStringValue(*result);
-    if (mReturnRelativeURLs)
+    nsCAutoString spec;
+    nsIURI* url = value.GetURLValue();
+    if (url) {
+      url->GetSpec(spec);
+      nsAutoString* result = new NS_ConvertUTF8toUTF16(spec);
+      if (mReturnRelativeURLs)
         EqualizeURL(result);
-    mResults->AppendElement((void*)result);
-    mResultCount++;
+      mResults->AppendElement(result);
+      mResultCount++;
+    }
   }
 
   return NS_OK;
diff --git a/mozilla/layout/base/nsCSSFrameConstructor.cpp b/mozilla/layout/base/nsCSSFrameConstructor.cpp
index b156ed393f6..c826f880248 100644
--- a/mozilla/layout/base/nsCSSFrameConstructor.cpp
+++ b/mozilla/layout/base/nsCSSFrameConstructor.cpp
@@ -1367,9 +1367,8 @@ nsCSSFrameConstructor::CreateGeneratedFrameFor(nsIPresContext*       aPresContex
   *aFrame = nsnull;  // initialize OUT parameter
 
   // Get the content value
-  nsStyleContentType  type;
-  nsAutoString        contentString;
-  aStyleContent->GetContentAt(aContentIndex, type, contentString);
+  const nsStyleContentData &data = aStyleContent->ContentAt(aContentIndex);
+  nsStyleContentType  type = data.mType;
 
   nsCOMPtr<nsIPresShell> shell;
   aPresContext->GetShell(getter_AddRefs(shell));
@@ -1395,8 +1394,10 @@ nsCSSFrameConstructor::CreateGeneratedFrameFor(nsIPresContext*       aPresContex
     rv = ef->CreateInstanceByTag(nodeInfo,getter_AddRefs(content));
     NS_ENSURE_SUCCESS(rv, rv);
 
-    content->SetAttr(kNameSpaceID_None, nsHTMLAtoms::src, contentString,
-                     PR_FALSE);
+    nsCAutoString spec;
+    data.mContent.mURL->GetSpec(spec); // XXXldb Ugh.
+    content->SetAttr(kNameSpaceID_None, nsHTMLAtoms::src,
+                     NS_ConvertUTF8toUCS2(spec), PR_FALSE);
 
     // Set aContent as the parent content and set the document object. This
     // way event handling works
@@ -1421,6 +1422,8 @@ nsCSSFrameConstructor::CreateGeneratedFrameFor(nsIPresContext*       aPresContex
 
   } else {
 
+    nsAutoString contentString(data.mContent.mString);
+
     switch (type) {
     case eStyleContentType_String:
       break;
@@ -3356,7 +3359,7 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
   const nsStyleDisplay* display = styleContext->GetStyleDisplay();
 
   // Ensure that our XBL bindings are installed.
-  if (!display->mBinding.IsEmpty()) {
+  if (display->mBinding) {
     // Get the XBL loader.
     nsresult rv;
     PRBool resolveStyle;
@@ -7112,7 +7115,7 @@ nsCSSFrameConstructor::ConstructFrameInternal( nsIPresShell*            aPresShe
   {
     
     // Ensure that our XBL bindings are installed.
-    if (!display->mBinding.IsEmpty()) {
+    if (display->mBinding) {
       // Get the XBL loader.
       nsresult rv;
       // Load the bindings.
diff --git a/mozilla/layout/base/nsCSSRendering.cpp b/mozilla/layout/base/nsCSSRendering.cpp
index bda5c1108cd..90b60a34cb1 100644
--- a/mozilla/layout/base/nsCSSRendering.cpp
+++ b/mozilla/layout/base/nsCSSRendering.cpp
@@ -2926,7 +2926,7 @@ nsCSSRendering::PaintBackgroundWithSC(nsIPresContext* aPresContext,
   }
 
   // if there is no background image or background images are turned off, try a color.
-  if (aColor.mBackgroundImage.IsEmpty() || !canDrawBackgroundImage) {
+  if (!aColor.mBackgroundImage || !canDrawBackgroundImage) {
     PaintBackgroundColor(aPresContext, aRenderingContext, aForFrame, bgClipArea,
                          aColor, aBorder, aPadding, canDrawBackgroundColor);
     return;
diff --git a/mozilla/layout/base/nsFrameManager.cpp b/mozilla/layout/base/nsFrameManager.cpp
index 80615d5bf52..5cdff410f61 100644
--- a/mozilla/layout/base/nsFrameManager.cpp
+++ b/mozilla/layout/base/nsFrameManager.cpp
@@ -1564,12 +1564,11 @@ HasAttributeContent(nsStyleContext* aStyleContext,
     const nsStyleContent* content = aStyleContext->GetStyleContent();
     PRUint32 count = content->ContentCount();
     while ((0 < count) && (! result)) {
-      nsStyleContentType  contentType;
-      nsAutoString        contentString;
-      content->GetContentAt(--count, contentType, contentString);
-      if (eStyleContentType_Attr == contentType) {
+      const nsStyleContentData &data = content->ContentAt(--count);
+      if (eStyleContentType_Attr == data.mType) {
         nsIAtom* attrName = nsnull;
         PRInt32 attrNameSpace = kNameSpaceID_None;
+        nsAutoString contentString(data.mContent.mString);
         PRInt32 barIndex = contentString.FindChar('|'); // CSS namespace delimiter
         if (-1 != barIndex) {
           nsAutoString  nameSpaceVal;
@@ -1731,8 +1730,12 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
         const nsStyleBackground* oldColor = oldContext->GetStyleBackground();
         const nsStyleBackground* newColor = newContext->GetStyleBackground();
 
-        if (!oldColor->mBackgroundImage.IsEmpty() &&
-            oldColor->mBackgroundImage != newColor->mBackgroundImage) {
+        PRBool equal;
+        if (oldColor->mBackgroundImage &&
+            (!newColor->mBackgroundImage ||
+             NS_FAILED(oldColor->mBackgroundImage->Equals(
+                                        newColor->mBackgroundImage, &equal)) ||
+             !equal)) {
           // stop the image loading for the frame, the image has changed
           aPresContext->StopImagesFor(aFrame);
         }
diff --git a/mozilla/layout/base/nsPresContext.cpp b/mozilla/layout/base/nsPresContext.cpp
index b46330a52d0..fafab68d844 100644
--- a/mozilla/layout/base/nsPresContext.cpp
+++ b/mozilla/layout/base/nsPresContext.cpp
@@ -985,13 +985,14 @@ nsPresContext::ProbePseudoStyleContextFor(nsIContent* aParentContent,
 }
 
 NS_IMETHODIMP
-nsPresContext::GetXBLBindingURL(nsIContent* aContent, nsAString& aResult)
+nsPresContext::GetXBLBindingURL(nsIContent* aContent, nsIURI** aResult)
 {
   nsRefPtr<nsStyleContext> sc;
   sc = ResolveStyleContextFor(aContent, nsnull);
   NS_ENSURE_TRUE(sc, NS_ERROR_FAILURE);
 
-  aResult = sc->GetStyleDisplay()->mBinding;
+  *aResult = sc->GetStyleDisplay()->mBinding;
+  NS_IF_ADDREF(*aResult);
   return NS_OK;
 }
 
@@ -1357,7 +1358,7 @@ nsPresContext::GetImageLoadFlags(nsLoadFlags& aLoadFlags)
 }
 
 NS_IMETHODIMP
-nsPresContext::LoadImage(const nsString& aURL,
+nsPresContext::LoadImage(nsIURI* aURL,
                          nsIFrame* aTargetFrame,
                          imgIRequest **aRequest)
 {
@@ -1368,18 +1369,6 @@ nsPresContext::LoadImage(const nsString& aURL,
   nsVoidKey key(aTargetFrame);
   nsImageLoader *loader = NS_REINTERPRET_CAST(nsImageLoader*, mImageLoaders.Get(&key)); // addrefs
 
-  nsCOMPtr<nsIDocument> doc;
-  rv = mShell->GetDocument(getter_AddRefs(doc));
-  if (NS_FAILED(rv)) return rv;
-
-  nsCOMPtr<nsIURI> baseURI;
-  doc->GetBaseURL(getter_AddRefs(baseURI));
-
-  nsCOMPtr<nsIURI> uri;
-  nsCOMPtr<nsIIOService> ioService;
-  GetIOService(getter_AddRefs(ioService));
-  NS_NewURI(getter_AddRefs(uri), aURL, nsnull, baseURI, ioService);
-
   if (!loader) {
     nsIContent* content = aTargetFrame->GetContent();
 
@@ -1402,7 +1391,7 @@ nsPresContext::LoadImage(const nsString& aURL,
 
           PRBool shouldLoad = PR_TRUE;
           rv = NS_CheckContentLoadPolicy(nsIContentPolicy::IMAGE,
-                                         uri, element, domWin, &shouldLoad);
+                                         aURL, element, domWin, &shouldLoad);
           if (NS_SUCCEEDED(rv) && !shouldLoad)
             return NS_ERROR_FAILURE;
         }
@@ -1431,7 +1420,7 @@ nsPresContext::LoadImage(const nsString& aURL,
     aTargetFrame->AddStateBits(NS_FRAME_HAS_LOADED_IMAGES);
   }
 
-  loader->Load(uri);
+  loader->Load(aURL);
 
   loader->GetRequest(aRequest);
 
diff --git a/mozilla/layout/base/nsPresContext.h b/mozilla/layout/base/nsPresContext.h
index 846bc91a731..2d1c61573d6 100644
--- a/mozilla/layout/base/nsPresContext.h
+++ b/mozilla/layout/base/nsPresContext.h
@@ -247,10 +247,9 @@ public:
  
    /**
     * Resolve a new style context for a content node and return the URL
-    * for its XBL binding, or the empty string if it has no binding
-    * specified in CSS.
+    * for its XBL binding, or null if it has no binding specified in CSS.
     */
-   NS_IMETHOD GetXBLBindingURL(nsIContent* aContent, nsAString& aResult) = 0;
+   NS_IMETHOD GetXBLBindingURL(nsIContent* aContent, nsIURI** aResult) = 0;
 
   /** 
    * For a given frame tree, get a new style context that is the equivalent
@@ -319,7 +318,7 @@ public:
    * method will be invoked (via the ViewManager) so that the
    * appropriate damage repair is done.
    */
-  NS_IMETHOD LoadImage(const nsString& aURL,
+  NS_IMETHOD LoadImage(nsIURI* aURL,
                        nsIFrame* aTargetFrame,
                        imgIRequest **aRequest) = 0;
 
diff --git a/mozilla/layout/base/public/nsIPresContext.h b/mozilla/layout/base/public/nsIPresContext.h
index 846bc91a731..2d1c61573d6 100644
--- a/mozilla/layout/base/public/nsIPresContext.h
+++ b/mozilla/layout/base/public/nsIPresContext.h
@@ -247,10 +247,9 @@ public:
  
    /**
     * Resolve a new style context for a content node and return the URL
-    * for its XBL binding, or the empty string if it has no binding
-    * specified in CSS.
+    * for its XBL binding, or null if it has no binding specified in CSS.
     */
-   NS_IMETHOD GetXBLBindingURL(nsIContent* aContent, nsAString& aResult) = 0;
+   NS_IMETHOD GetXBLBindingURL(nsIContent* aContent, nsIURI** aResult) = 0;
 
   /** 
    * For a given frame tree, get a new style context that is the equivalent
@@ -319,7 +318,7 @@ public:
    * method will be invoked (via the ViewManager) so that the
    * appropriate damage repair is done.
    */
-  NS_IMETHOD LoadImage(const nsString& aURL,
+  NS_IMETHOD LoadImage(nsIURI* aURL,
                        nsIFrame* aTargetFrame,
                        imgIRequest **aRequest) = 0;
 
diff --git a/mozilla/layout/base/public/nsPresContext.h b/mozilla/layout/base/public/nsPresContext.h
index 846bc91a731..2d1c61573d6 100644
--- a/mozilla/layout/base/public/nsPresContext.h
+++ b/mozilla/layout/base/public/nsPresContext.h
@@ -247,10 +247,9 @@ public:
  
    /**
     * Resolve a new style context for a content node and return the URL
-    * for its XBL binding, or the empty string if it has no binding
-    * specified in CSS.
+    * for its XBL binding, or null if it has no binding specified in CSS.
     */
-   NS_IMETHOD GetXBLBindingURL(nsIContent* aContent, nsAString& aResult) = 0;
+   NS_IMETHOD GetXBLBindingURL(nsIContent* aContent, nsIURI** aResult) = 0;
 
   /** 
    * For a given frame tree, get a new style context that is the equivalent
@@ -319,7 +318,7 @@ public:
    * method will be invoked (via the ViewManager) so that the
    * appropriate damage repair is done.
    */
-  NS_IMETHOD LoadImage(const nsString& aURL,
+  NS_IMETHOD LoadImage(nsIURI* aURL,
                        nsIFrame* aTargetFrame,
                        imgIRequest **aRequest) = 0;
 
diff --git a/mozilla/layout/base/src/nsPresContext.cpp b/mozilla/layout/base/src/nsPresContext.cpp
index b46330a52d0..fafab68d844 100644
--- a/mozilla/layout/base/src/nsPresContext.cpp
+++ b/mozilla/layout/base/src/nsPresContext.cpp
@@ -985,13 +985,14 @@ nsPresContext::ProbePseudoStyleContextFor(nsIContent* aParentContent,
 }
 
 NS_IMETHODIMP
-nsPresContext::GetXBLBindingURL(nsIContent* aContent, nsAString& aResult)
+nsPresContext::GetXBLBindingURL(nsIContent* aContent, nsIURI** aResult)
 {
   nsRefPtr<nsStyleContext> sc;
   sc = ResolveStyleContextFor(aContent, nsnull);
   NS_ENSURE_TRUE(sc, NS_ERROR_FAILURE);
 
-  aResult = sc->GetStyleDisplay()->mBinding;
+  *aResult = sc->GetStyleDisplay()->mBinding;
+  NS_IF_ADDREF(*aResult);
   return NS_OK;
 }
 
@@ -1357,7 +1358,7 @@ nsPresContext::GetImageLoadFlags(nsLoadFlags& aLoadFlags)
 }
 
 NS_IMETHODIMP
-nsPresContext::LoadImage(const nsString& aURL,
+nsPresContext::LoadImage(nsIURI* aURL,
                          nsIFrame* aTargetFrame,
                          imgIRequest **aRequest)
 {
@@ -1368,18 +1369,6 @@ nsPresContext::LoadImage(const nsString& aURL,
   nsVoidKey key(aTargetFrame);
   nsImageLoader *loader = NS_REINTERPRET_CAST(nsImageLoader*, mImageLoaders.Get(&key)); // addrefs
 
-  nsCOMPtr<nsIDocument> doc;
-  rv = mShell->GetDocument(getter_AddRefs(doc));
-  if (NS_FAILED(rv)) return rv;
-
-  nsCOMPtr<nsIURI> baseURI;
-  doc->GetBaseURL(getter_AddRefs(baseURI));
-
-  nsCOMPtr<nsIURI> uri;
-  nsCOMPtr<nsIIOService> ioService;
-  GetIOService(getter_AddRefs(ioService));
-  NS_NewURI(getter_AddRefs(uri), aURL, nsnull, baseURI, ioService);
-
   if (!loader) {
     nsIContent* content = aTargetFrame->GetContent();
 
@@ -1402,7 +1391,7 @@ nsPresContext::LoadImage(const nsString& aURL,
 
           PRBool shouldLoad = PR_TRUE;
           rv = NS_CheckContentLoadPolicy(nsIContentPolicy::IMAGE,
-                                         uri, element, domWin, &shouldLoad);
+                                         aURL, element, domWin, &shouldLoad);
           if (NS_SUCCEEDED(rv) && !shouldLoad)
             return NS_ERROR_FAILURE;
         }
@@ -1431,7 +1420,7 @@ nsPresContext::LoadImage(const nsString& aURL,
     aTargetFrame->AddStateBits(NS_FRAME_HAS_LOADED_IMAGES);
   }
 
-  loader->Load(uri);
+  loader->Load(aURL);
 
   loader->GetRequest(aRequest);
 
diff --git a/mozilla/layout/base/src/nsPresContext.h b/mozilla/layout/base/src/nsPresContext.h
index f4bb03af3a6..9ca3f93073c 100644
--- a/mozilla/layout/base/src/nsPresContext.h
+++ b/mozilla/layout/base/src/nsPresContext.h
@@ -105,7 +105,7 @@ public:
                              nsIAtom* aPseudoTag,
                              nsStyleContext* aParentContext);
 
-  NS_IMETHOD GetXBLBindingURL(nsIContent* aContent, nsAString& aResult);
+  NS_IMETHOD GetXBLBindingURL(nsIContent* aContent, nsIURI** aResult);
   NS_IMETHOD ReParentStyleContext(nsIFrame* aFrame, 
                                   nsStyleContext* aNewParentContext);
   NS_IMETHOD GetMetricsFor(const nsFont& aFont, nsIFontMetrics** aResult);
@@ -133,7 +133,7 @@ public:
   NS_IMETHOD SetDefaultLinkColor(nscolor aColor);
   NS_IMETHOD SetDefaultVisitedLinkColor(nscolor aColor);
 
-  NS_IMETHOD LoadImage(const nsString& aURL,
+  NS_IMETHOD LoadImage(nsIURI* aURL,
                        nsIFrame* aTargetFrame,
                        imgIRequest **aRequest);
 
diff --git a/mozilla/layout/forms/nsGfxCheckboxControlFrame.cpp b/mozilla/layout/forms/nsGfxCheckboxControlFrame.cpp
index dba59377cd3..9918a1830be 100644
--- a/mozilla/layout/forms/nsGfxCheckboxControlFrame.cpp
+++ b/mozilla/layout/forms/nsGfxCheckboxControlFrame.cpp
@@ -231,7 +231,7 @@ nsGfxCheckboxControlFrame::Paint(nsIPresContext*   aPresContext,
     if (!mCheckButtonFaceStyle && GetCheckboxState()) {
       const nsStyleBackground* myColor = mCheckButtonFaceStyle->GetStyleBackground();
 
-      if (!myColor->mBackgroundImage.IsEmpty()) {
+      if (myColor->mBackgroundImage) {
         const nsStyleBorder* myBorder = mCheckButtonFaceStyle->GetStyleBorder();
         const nsStylePadding* myPadding = mCheckButtonFaceStyle->GetStylePadding();
         const nsStylePosition* myPosition = mCheckButtonFaceStyle->GetStylePosition();
diff --git a/mozilla/layout/generic/nsBulletFrame.cpp b/mozilla/layout/generic/nsBulletFrame.cpp
index 1ad649a1b61..d78847be840 100644
--- a/mozilla/layout/generic/nsBulletFrame.cpp
+++ b/mozilla/layout/generic/nsBulletFrame.cpp
@@ -124,9 +124,8 @@ nsBulletFrame::Init(nsIPresContext*  aPresContext,
   
   nsresult  rv = nsFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
 
-  const nsStyleList* myList = GetStyleList();
-
-  if (!myList->mListStyleImage.IsEmpty()) {
+  nsIURI *imgURI = GetStyleList()->mListStyleImage;
+  if (imgURI) {
     nsCOMPtr<imgILoader> il(do_GetService("@mozilla.org/image/loader;1", &rv));
     if (NS_FAILED(rv))
       return rv;
@@ -134,12 +133,6 @@ nsBulletFrame::Init(nsIPresContext*  aPresContext,
     nsCOMPtr<nsILoadGroup> loadGroup;
     GetLoadGroup(aPresContext, getter_AddRefs(loadGroup));
 
-    nsCOMPtr<nsIURI> baseURI;
-    mContent->GetBaseURL(getter_AddRefs(baseURI));
-
-    nsCOMPtr<nsIURI> imgURI;
-    NS_NewURI(getter_AddRefs(imgURI), myList->mListStyleImage, nsnull, baseURI);
-
     // Get the document URI for the referrer...
     nsCOMPtr<nsIURI> documentURI;
     nsCOMPtr<nsIDocument> doc;
@@ -201,7 +194,7 @@ nsBulletFrame::Paint(nsIPresContext*      aPresContext,
     const nsStyleList* myList = GetStyleList();
     PRUint8 listStyleType = myList->mListStyleType;
 
-    if (!myList->mListStyleImage.IsEmpty() && mImageRequest) {
+    if (myList->mListStyleImage && mImageRequest) {
       PRUint32 status;
       mImageRequest->GetImageStatus(&status);
       if (status & imgIRequest::STATUS_LOAD_COMPLETE &&
@@ -1379,7 +1372,7 @@ nsBulletFrame::GetDesiredSize(nsIPresContext*  aCX,
   const nsStyleList* myList = GetStyleList();
   nscoord ascent;
 
-  if (!myList->mListStyleImage.IsEmpty() && mImageRequest) {
+  if (myList->mListStyleImage && mImageRequest) {
     PRUint32 status;
     mImageRequest->GetImageStatus(&status);
     if (status & imgIRequest::STATUS_SIZE_AVAILABLE &&
@@ -1595,12 +1588,9 @@ nsBulletFrame::Reflow(nsIPresContext* aPresContext,
   }
 
   if (isStyleChange) {
-    nsCOMPtr<nsIURI> baseURI;
-    mContent->GetBaseURL(getter_AddRefs(baseURI));
+    nsIURI *newURI = GetStyleList()->mListStyleImage;
 
-    const nsStyleList* myList = GetStyleList();
-
-    if (!myList->mListStyleImage.IsEmpty()) {
+    if (newURI) {
 
       if (!mListener) {
         nsBulletListener *listener;
@@ -1612,10 +1602,6 @@ nsBulletFrame::Reflow(nsIPresContext* aPresContext,
         NS_RELEASE(listener);
       }
 
-
-      nsCOMPtr<nsIURI> newURI;
-      NS_NewURI(getter_AddRefs(newURI), myList->mListStyleImage, nsnull, baseURI);
-
       PRBool needNewRequest = PR_TRUE;
 
       if (mImageRequest) {
diff --git a/mozilla/layout/html/base/src/nsBulletFrame.cpp b/mozilla/layout/html/base/src/nsBulletFrame.cpp
index 1ad649a1b61..d78847be840 100644
--- a/mozilla/layout/html/base/src/nsBulletFrame.cpp
+++ b/mozilla/layout/html/base/src/nsBulletFrame.cpp
@@ -124,9 +124,8 @@ nsBulletFrame::Init(nsIPresContext*  aPresContext,
   
   nsresult  rv = nsFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
 
-  const nsStyleList* myList = GetStyleList();
-
-  if (!myList->mListStyleImage.IsEmpty()) {
+  nsIURI *imgURI = GetStyleList()->mListStyleImage;
+  if (imgURI) {
     nsCOMPtr<imgILoader> il(do_GetService("@mozilla.org/image/loader;1", &rv));
     if (NS_FAILED(rv))
       return rv;
@@ -134,12 +133,6 @@ nsBulletFrame::Init(nsIPresContext*  aPresContext,
     nsCOMPtr<nsILoadGroup> loadGroup;
     GetLoadGroup(aPresContext, getter_AddRefs(loadGroup));
 
-    nsCOMPtr<nsIURI> baseURI;
-    mContent->GetBaseURL(getter_AddRefs(baseURI));
-
-    nsCOMPtr<nsIURI> imgURI;
-    NS_NewURI(getter_AddRefs(imgURI), myList->mListStyleImage, nsnull, baseURI);
-
     // Get the document URI for the referrer...
     nsCOMPtr<nsIURI> documentURI;
     nsCOMPtr<nsIDocument> doc;
@@ -201,7 +194,7 @@ nsBulletFrame::Paint(nsIPresContext*      aPresContext,
     const nsStyleList* myList = GetStyleList();
     PRUint8 listStyleType = myList->mListStyleType;
 
-    if (!myList->mListStyleImage.IsEmpty() && mImageRequest) {
+    if (myList->mListStyleImage && mImageRequest) {
       PRUint32 status;
       mImageRequest->GetImageStatus(&status);
       if (status & imgIRequest::STATUS_LOAD_COMPLETE &&
@@ -1379,7 +1372,7 @@ nsBulletFrame::GetDesiredSize(nsIPresContext*  aCX,
   const nsStyleList* myList = GetStyleList();
   nscoord ascent;
 
-  if (!myList->mListStyleImage.IsEmpty() && mImageRequest) {
+  if (myList->mListStyleImage && mImageRequest) {
     PRUint32 status;
     mImageRequest->GetImageStatus(&status);
     if (status & imgIRequest::STATUS_SIZE_AVAILABLE &&
@@ -1595,12 +1588,9 @@ nsBulletFrame::Reflow(nsIPresContext* aPresContext,
   }
 
   if (isStyleChange) {
-    nsCOMPtr<nsIURI> baseURI;
-    mContent->GetBaseURL(getter_AddRefs(baseURI));
+    nsIURI *newURI = GetStyleList()->mListStyleImage;
 
-    const nsStyleList* myList = GetStyleList();
-
-    if (!myList->mListStyleImage.IsEmpty()) {
+    if (newURI) {
 
       if (!mListener) {
         nsBulletListener *listener;
@@ -1612,10 +1602,6 @@ nsBulletFrame::Reflow(nsIPresContext* aPresContext,
         NS_RELEASE(listener);
       }
 
-
-      nsCOMPtr<nsIURI> newURI;
-      NS_NewURI(getter_AddRefs(newURI), myList->mListStyleImage, nsnull, baseURI);
-
       PRBool needNewRequest = PR_TRUE;
 
       if (mImageRequest) {
diff --git a/mozilla/layout/html/base/src/nsFrameManager.cpp b/mozilla/layout/html/base/src/nsFrameManager.cpp
index 80615d5bf52..5cdff410f61 100644
--- a/mozilla/layout/html/base/src/nsFrameManager.cpp
+++ b/mozilla/layout/html/base/src/nsFrameManager.cpp
@@ -1564,12 +1564,11 @@ HasAttributeContent(nsStyleContext* aStyleContext,
     const nsStyleContent* content = aStyleContext->GetStyleContent();
     PRUint32 count = content->ContentCount();
     while ((0 < count) && (! result)) {
-      nsStyleContentType  contentType;
-      nsAutoString        contentString;
-      content->GetContentAt(--count, contentType, contentString);
-      if (eStyleContentType_Attr == contentType) {
+      const nsStyleContentData &data = content->ContentAt(--count);
+      if (eStyleContentType_Attr == data.mType) {
         nsIAtom* attrName = nsnull;
         PRInt32 attrNameSpace = kNameSpaceID_None;
+        nsAutoString contentString(data.mContent.mString);
         PRInt32 barIndex = contentString.FindChar('|'); // CSS namespace delimiter
         if (-1 != barIndex) {
           nsAutoString  nameSpaceVal;
@@ -1731,8 +1730,12 @@ FrameManager::ReResolveStyleContext(nsIPresContext* aPresContext,
         const nsStyleBackground* oldColor = oldContext->GetStyleBackground();
         const nsStyleBackground* newColor = newContext->GetStyleBackground();
 
-        if (!oldColor->mBackgroundImage.IsEmpty() &&
-            oldColor->mBackgroundImage != newColor->mBackgroundImage) {
+        PRBool equal;
+        if (oldColor->mBackgroundImage &&
+            (!newColor->mBackgroundImage ||
+             NS_FAILED(oldColor->mBackgroundImage->Equals(
+                                        newColor->mBackgroundImage, &equal)) ||
+             !equal)) {
           // stop the image loading for the frame, the image has changed
           aPresContext->StopImagesFor(aFrame);
         }
diff --git a/mozilla/layout/html/forms/src/nsGfxCheckboxControlFrame.cpp b/mozilla/layout/html/forms/src/nsGfxCheckboxControlFrame.cpp
index dba59377cd3..9918a1830be 100644
--- a/mozilla/layout/html/forms/src/nsGfxCheckboxControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsGfxCheckboxControlFrame.cpp
@@ -231,7 +231,7 @@ nsGfxCheckboxControlFrame::Paint(nsIPresContext*   aPresContext,
     if (!mCheckButtonFaceStyle && GetCheckboxState()) {
       const nsStyleBackground* myColor = mCheckButtonFaceStyle->GetStyleBackground();
 
-      if (!myColor->mBackgroundImage.IsEmpty()) {
+      if (myColor->mBackgroundImage) {
         const nsStyleBorder* myBorder = mCheckButtonFaceStyle->GetStyleBorder();
         const nsStylePadding* myPadding = mCheckButtonFaceStyle->GetStylePadding();
         const nsStylePosition* myPosition = mCheckButtonFaceStyle->GetStylePosition();
diff --git a/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp b/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
index b156ed393f6..c826f880248 100644
--- a/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
+++ b/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
@@ -1367,9 +1367,8 @@ nsCSSFrameConstructor::CreateGeneratedFrameFor(nsIPresContext*       aPresContex
   *aFrame = nsnull;  // initialize OUT parameter
 
   // Get the content value
-  nsStyleContentType  type;
-  nsAutoString        contentString;
-  aStyleContent->GetContentAt(aContentIndex, type, contentString);
+  const nsStyleContentData &data = aStyleContent->ContentAt(aContentIndex);
+  nsStyleContentType  type = data.mType;
 
   nsCOMPtr<nsIPresShell> shell;
   aPresContext->GetShell(getter_AddRefs(shell));
@@ -1395,8 +1394,10 @@ nsCSSFrameConstructor::CreateGeneratedFrameFor(nsIPresContext*       aPresContex
     rv = ef->CreateInstanceByTag(nodeInfo,getter_AddRefs(content));
     NS_ENSURE_SUCCESS(rv, rv);
 
-    content->SetAttr(kNameSpaceID_None, nsHTMLAtoms::src, contentString,
-                     PR_FALSE);
+    nsCAutoString spec;
+    data.mContent.mURL->GetSpec(spec); // XXXldb Ugh.
+    content->SetAttr(kNameSpaceID_None, nsHTMLAtoms::src,
+                     NS_ConvertUTF8toUCS2(spec), PR_FALSE);
 
     // Set aContent as the parent content and set the document object. This
     // way event handling works
@@ -1421,6 +1422,8 @@ nsCSSFrameConstructor::CreateGeneratedFrameFor(nsIPresContext*       aPresContex
 
   } else {
 
+    nsAutoString contentString(data.mContent.mString);
+
     switch (type) {
     case eStyleContentType_String:
       break;
@@ -3356,7 +3359,7 @@ nsCSSFrameConstructor::ConstructDocElementFrame(nsIPresShell*        aPresShell,
   const nsStyleDisplay* display = styleContext->GetStyleDisplay();
 
   // Ensure that our XBL bindings are installed.
-  if (!display->mBinding.IsEmpty()) {
+  if (display->mBinding) {
     // Get the XBL loader.
     nsresult rv;
     PRBool resolveStyle;
@@ -7112,7 +7115,7 @@ nsCSSFrameConstructor::ConstructFrameInternal( nsIPresShell*            aPresShe
   {
     
     // Ensure that our XBL bindings are installed.
-    if (!display->mBinding.IsEmpty()) {
+    if (display->mBinding) {
       // Get the XBL loader.
       nsresult rv;
       // Load the bindings.
diff --git a/mozilla/layout/html/style/src/nsCSSRendering.cpp b/mozilla/layout/html/style/src/nsCSSRendering.cpp
index bda5c1108cd..90b60a34cb1 100644
--- a/mozilla/layout/html/style/src/nsCSSRendering.cpp
+++ b/mozilla/layout/html/style/src/nsCSSRendering.cpp
@@ -2926,7 +2926,7 @@ nsCSSRendering::PaintBackgroundWithSC(nsIPresContext* aPresContext,
   }
 
   // if there is no background image or background images are turned off, try a color.
-  if (aColor.mBackgroundImage.IsEmpty() || !canDrawBackgroundImage) {
+  if (!aColor.mBackgroundImage || !canDrawBackgroundImage) {
     PaintBackgroundColor(aPresContext, aRenderingContext, aForFrame, bgClipArea,
                          aColor, aBorder, aPadding, canDrawBackgroundColor);
     return;
diff --git a/mozilla/layout/style/nsCSSDeclaration.cpp b/mozilla/layout/style/nsCSSDeclaration.cpp
index dcb3c6f3a5d..dd26f79903b 100644
--- a/mozilla/layout/style/nsCSSDeclaration.cpp
+++ b/mozilla/layout/style/nsCSSDeclaration.cpp
@@ -282,8 +282,6 @@ PRBool nsCSSDeclaration::AppendCSSValueToString(nsCSSProperty aProperty, const n
 
   if ((eCSSUnit_String <= unit) && (unit <= eCSSUnit_Counters)) {
     switch (unit) {
-      case eCSSUnit_URL:      aResult.Append(NS_LITERAL_STRING("url("));
-        break;
       case eCSSUnit_Attr:     aResult.Append(NS_LITERAL_STRING("attr("));
         break;
       case eCSSUnit_Counter:  aResult.Append(NS_LITERAL_STRING("counter("));
@@ -385,7 +383,7 @@ PRBool nsCSSDeclaration::AppendCSSValueToString(nsCSSProperty aProperty, const n
       aResult.Append(NS_ConvertASCIItoUCS2(name));
     }
   }
-  else if (eCSSUnit_Color == unit){
+  else if (eCSSUnit_Color == unit) {
     nsAutoString tmpStr;
     nscolor color = aValue.GetColorValue();
 
@@ -406,6 +404,13 @@ PRBool nsCSSDeclaration::AppendCSSValueToString(nsCSSProperty aProperty, const n
 
     aResult.Append(PRUnichar(')'));
   }
+  else if (eCSSUnit_URL == unit) {
+    nsCAutoString spec;
+    aValue.GetURLValue()->GetSpec(spec);
+    aResult.Append(NS_LITERAL_STRING("url(") +
+                   NS_ConvertUTF8toUCS2(spec) +
+                   NS_LITERAL_STRING(")"));
+  }
   else if (eCSSUnit_Percent == unit) {
     nsAutoString tmpStr;
     tmpStr.AppendFloat(aValue.GetPercentValue() * 100.0f);
@@ -426,7 +431,7 @@ PRBool nsCSSDeclaration::AppendCSSValueToString(nsCSSProperty aProperty, const n
     case eCSSUnit_Normal:       aResult.Append(NS_LITERAL_STRING("normal"));   break;
 
     case eCSSUnit_String:       break;
-    case eCSSUnit_URL:
+    case eCSSUnit_URL:          break;
     case eCSSUnit_Attr:
     case eCSSUnit_Counter:
     case eCSSUnit_Counters:     aResult.Append(PRUnichar(')'));    break;
diff --git a/mozilla/layout/style/nsCSSParser.cpp b/mozilla/layout/style/nsCSSParser.cpp
index b1cdffd94c9..b3dba2dacfe 100644
--- a/mozilla/layout/style/nsCSSParser.cpp
+++ b/mozilla/layout/style/nsCSSParser.cpp
@@ -3602,13 +3602,6 @@ PRBool CSSParserImpl::ParseAttr(PRInt32& aErrorCode, nsCSSValue& aValue)
   return PR_FALSE;
 }
 
-inline static PRBool
-css_RequiresAbsoluteURI(const nsString& uri)
-{
-  // cheap shot at figuring out if this requires an absolute url translation
-  return !StringBeginsWith(uri, NS_LITERAL_STRING("chrome:"));
-}
-
 PRBool CSSParserImpl::ParseURL(PRInt32& aErrorCode, nsCSSValue& aValue)
 {
   if (ExpectSymbol(aErrorCode, '(', PR_FALSE)) {
@@ -3620,16 +3613,12 @@ PRBool CSSParserImpl::ParseURL(PRInt32& aErrorCode, nsCSSValue& aValue)
       // Translate url into an absolute url if the url is relative to
       // the style sheet.
       // XXX editors won't like this - too bad for now
-      nsAutoString absURL;
-      nsresult rv = NS_ERROR_FAILURE;
-      if (mURL && css_RequiresAbsoluteURI(tk->mIdent)) {
-        rv = NS_MakeAbsoluteURI(absURL, tk->mIdent, mURL);
-      }
-      if (NS_FAILED(rv)) {
-        absURL = tk->mIdent;
-      }
+      nsCOMPtr<nsIURI> url;
+      NS_NewURI(getter_AddRefs(url), tk->mIdent, nsnull, mURL);
       if (ExpectSymbol(aErrorCode, ')', PR_TRUE)) {
-        aValue.SetStringValue(absURL, eCSSUnit_URL);
+        // Set a null value on failure.  Most failure cases should be
+        // NS_ERROR_MALFORMED_URI.
+        aValue.SetURLValue(url);
         return PR_TRUE;
       }
     }
diff --git a/mozilla/layout/style/nsCSSValue.cpp b/mozilla/layout/style/nsCSSValue.cpp
index bf5e042e2c0..fc2d28c4cf4 100644
--- a/mozilla/layout/style/nsCSSValue.cpp
+++ b/mozilla/layout/style/nsCSSValue.cpp
@@ -90,6 +90,13 @@ nsCSSValue::nsCSSValue(nscolor aValue)
   mValue.mColor = aValue;
 }
 
+nsCSSValue::nsCSSValue(nsIURI* aValue)
+  : mUnit(eCSSUnit_URL)
+{
+  mValue.mURL = aValue;
+  NS_IF_ADDREF(aValue);
+}
+
 nsCSSValue::nsCSSValue(const nsCSSValue& aCopy)
   : mUnit(aCopy.mUnit)
 {
@@ -107,6 +114,10 @@ nsCSSValue::nsCSSValue(const nsCSSValue& aCopy)
   else if (eCSSUnit_Color == mUnit){
     mValue.mColor = aCopy.mValue.mColor;
   }
+  else if (eCSSUnit_URL == mUnit){
+    mValue.mURL = aCopy.mValue.mURL;
+    NS_IF_ADDREF(mValue.mURL);
+  }
   else {
     mValue.mFloat = aCopy.mValue.mFloat;
   }
@@ -127,6 +138,10 @@ nsCSSValue& nsCSSValue::operator=(const nsCSSValue& aCopy)
   else if (eCSSUnit_Color == mUnit){
     mValue.mColor = aCopy.mValue.mColor;
   }
+  else if (eCSSUnit_URL == mUnit){
+    mValue.mURL = aCopy.mValue.mURL;
+    NS_IF_ADDREF(mValue.mURL);
+  }
   else {
     mValue.mFloat = aCopy.mValue.mFloat;
   }
@@ -147,13 +162,20 @@ PRBool nsCSSValue::operator==(const nsCSSValue& aOther) const
       }
     }
     else if ((eCSSUnit_Integer <= mUnit) && (mUnit <= eCSSUnit_Enumerated)) {
-      return PRBool(mValue.mInt == aOther.mValue.mInt);
+      return mValue.mInt == aOther.mValue.mInt;
     }
-    else if (eCSSUnit_Color == mUnit){
-      return PRBool(mValue.mColor == aOther.mValue.mColor);
+    else if (eCSSUnit_Color == mUnit) {
+      return mValue.mColor == aOther.mValue.mColor;
+    }
+    else if (eCSSUnit_URL == mUnit) {
+      PRBool eq;
+      return (mValue.mURL == aOther.mValue.mURL || // handles null == null
+              (mValue.mURL && aOther.mValue.mURL &&
+               NS_SUCCEEDED(mValue.mURL->Equals(aOther.mValue.mURL, &eq)) &&
+               eq));
     }
     else {
-      return PRBool(mValue.mFloat == aOther.mValue.mFloat);
+      return mValue.mFloat == aOther.mValue.mFloat;
     }
   }
   return PR_FALSE;
@@ -189,6 +211,14 @@ void nsCSSValue::SetColorValue(nscolor aValue)
   mValue.mColor = aValue;
 }
 
+void nsCSSValue::SetURLValue(nsIURI* aValue)
+{
+  Reset();
+  mUnit = eCSSUnit_URL;
+  mValue.mURL = aValue;
+  NS_IF_ADDREF(mValue.mURL);
+}
+
 void nsCSSValue::SetAutoValue(void)
 {
   Reset();
@@ -261,7 +291,7 @@ void nsCSSValue::AppendToString(nsAString& aBuffer,
 
     aBuffer.Append(PRUnichar(']'));
   }
-  else if (eCSSUnit_Color == mUnit){
+  else if (eCSSUnit_Color == mUnit) {
     aBuffer.Append(NS_LITERAL_STRING("(0x"));
 
     nsAutoString intStr;
@@ -288,6 +318,15 @@ void nsCSSValue::AppendToString(nsAString& aBuffer,
 
     aBuffer.Append(PRUnichar(')'));
   }
+  else if (eCSSUnit_URL == mUnit) {
+    if (mValue.mURL) {
+      nsCAutoString spec;
+      mValue.mURL->GetSpec(spec);
+      AppendUTF8toUTF16(spec, aBuffer);
+    } else {
+      aBuffer.Append(NS_LITERAL_STRING("url(invalid-url:)"));
+    }
+  }
   else if (eCSSUnit_Percent == mUnit) {
     nsAutoString floatString;
     floatString.AppendFloat(mValue.mFloat * 100.0f);
@@ -351,4 +390,3 @@ void nsCSSValue::ToString(nsAString& aBuffer,
   aBuffer.Truncate();
   AppendToString(aBuffer, aPropID);
 }
-
diff --git a/mozilla/layout/style/nsCSSValue.h b/mozilla/layout/style/nsCSSValue.h
index 1afbf2443d7..3f730eab873 100644
--- a/mozilla/layout/style/nsCSSValue.h
+++ b/mozilla/layout/style/nsCSSValue.h
@@ -44,7 +44,7 @@
 #include "nsCoord.h"
 #include "nsCSSProperty.h"
 #include "nsUnitConversion.h"
-
+#include "nsIURI.h"
 
 enum nsCSSUnit {
   eCSSUnit_Null         = 0,      // (n/a) null unit, value is not specified
@@ -53,11 +53,11 @@ enum nsCSSUnit {
   eCSSUnit_Initial      = 3,      // (n/a) value is default UA value
   eCSSUnit_None         = 4,      // (n/a) value is none
   eCSSUnit_Normal       = 5,      // (n/a) value is normal (algorithmic, different than auto)
-  eCSSUnit_String       = 10,     // (nsString) a string value
-  eCSSUnit_URL          = 11,     // (nsString) a URL value
-  eCSSUnit_Attr         = 12,     // (nsString) a attr(string) value
-  eCSSUnit_Counter      = 13,     // (nsString) a counter(string,[string]) value
-  eCSSUnit_Counters     = 14,     // (nsString) a counters(string,string[,string]) value
+  eCSSUnit_String       = 10,     // (PRUnichar*) a string value
+  eCSSUnit_Attr         = 11,     // (PRUnichar*) a attr(string) value
+  eCSSUnit_Counter      = 12,     // (PRUnichar*) a counter(string,[string]) value
+  eCSSUnit_Counters     = 13,     // (PRUnichar*) a counters(string,string[,string]) value
+  eCSSUnit_URL          = 14,     // (nsIURI*) a URL value (null == invalid URI)
   eCSSUnit_Integer      = 50,     // (int) simple value
   eCSSUnit_Enumerated   = 51,     // (int) value has enumerated meaning
   eCSSUnit_Color        = 80,     // (color) an RGBA value
@@ -129,6 +129,7 @@ public:
   nsCSSValue(float aValue, nsCSSUnit aUnit);
   nsCSSValue(const nsAString& aValue, nsCSSUnit aUnit);
   nsCSSValue(nscolor aValue);
+  nsCSSValue(nsIURI* aValue);
   nsCSSValue(const nsCSSValue& aCopy);
   ~nsCSSValue(void)
   {
@@ -138,7 +139,11 @@ public:
 
   nsCSSValue&  operator=(const nsCSSValue& aCopy);
   PRBool      operator==(const nsCSSValue& aOther) const;
-  PRBool      operator!=(const nsCSSValue& aOther) const;
+
+  PRBool operator!=(const nsCSSValue& aOther) const
+  {
+    return !(*this == aOther);
+  }
 
   nsCSSUnit GetUnit(void) const { return mUnit; };
   PRBool    IsLengthUnit(void) const
@@ -154,11 +159,56 @@ public:
   PRBool    IsTimeUnit(void) const  
     { return PRBool((eCSSUnit_Seconds <= mUnit) && (mUnit <= eCSSUnit_Milliseconds)); }
 
-  PRInt32   GetIntValue(void) const;
-  float     GetPercentValue(void) const;
-  float     GetFloatValue(void) const;
-  nsAString& GetStringValue(nsAString& aBuffer) const;
-  nscolor   GetColorValue(void) const;
+  PRInt32 GetIntValue(void) const
+  {
+    NS_ASSERTION(mUnit == eCSSUnit_Integer || mUnit == eCSSUnit_Enumerated,
+                 "not an int value");
+    return mValue.mInt;
+  }
+
+  float GetPercentValue(void) const
+  {
+    NS_ASSERTION(mUnit == eCSSUnit_Percent, "not a percent value");
+    return mValue.mFloat;
+  }
+
+  float GetFloatValue(void) const
+  {
+    NS_ASSERTION(eCSSUnit_Number <= mUnit, "not a float value");
+    return mValue.mFloat;
+  }
+
+  nsAString& GetStringValue(nsAString& aBuffer) const
+  {
+    NS_ASSERTION(eCSSUnit_String <= mUnit && mUnit <= eCSSUnit_Counters,
+                 "not a string value");
+    aBuffer.Truncate();
+    if (nsnull != mValue.mString) {
+      aBuffer.Append(mValue.mString);
+    }
+    return aBuffer;
+  }
+
+  const PRUnichar* GetStringBufferValue() const
+  {
+    NS_ASSERTION(eCSSUnit_String <= mUnit && mUnit <= eCSSUnit_Counters,
+                 "not a string value");
+    return mValue.mString;
+  }
+
+  nscolor GetColorValue(void) const
+  {
+    NS_ASSERTION((mUnit == eCSSUnit_Color), "not a color value");
+    return mValue.mColor;
+  }
+
+  nsIURI* GetURLValue(void) const
+  {
+    NS_ASSERTION(mUnit == eCSSUnit_URL, "not a URL value");
+    return mValue.mURL;
+  }
+
+
   nscoord   GetLengthTwips(void) const
   {
     NS_ASSERTION(IsFixedLengthUnit(), "not a fixed length unit");
@@ -202,6 +252,8 @@ public:
     if ((eCSSUnit_String <= mUnit) && (mUnit <= eCSSUnit_Counters) &&
         (nsnull != mValue.mString)) {
       nsCRT::free(mValue.mString);
+    } else if (eCSSUnit_URL == mUnit) {
+      NS_IF_RELEASE(mValue.mURL);
     }
     mUnit = eCSSUnit_Null;
     mValue.mInt = 0;
@@ -227,6 +279,7 @@ public:
 
   void  SetStringValue(const nsAString& aValue, nsCSSUnit aUnit);
   void  SetColorValue(nscolor aValue);
+  void  SetURLValue(nsIURI* aURI);
   void  SetAutoValue(void);
   void  SetInheritValue(void);
   void  SetInitialValue(void);
@@ -234,6 +287,7 @@ public:
   void  SetNormalValue(void);
 
   // debugging methods only
+  // XXXldb Not anymore!
   void  AppendToString(nsAString& aBuffer, nsCSSProperty aPropID = eCSSProperty_UNKNOWN) const;
   void  ToString(nsAString& aBuffer, nsCSSProperty aPropID = eCSSProperty_UNKNOWN) const;
 
@@ -244,64 +298,9 @@ protected:
     float      mFloat;
     PRUnichar* mString;
     nscolor    mColor;
+    nsIURI*    mURL;
   }         mValue;
 };
 
-inline PRInt32 nsCSSValue::GetIntValue(void) const
-{
-  NS_ASSERTION((mUnit == eCSSUnit_Integer) ||
-               (mUnit == eCSSUnit_Enumerated), "not an int value");
-  if ((mUnit == eCSSUnit_Integer) ||
-      (mUnit == eCSSUnit_Enumerated)) {
-    return mValue.mInt;
-  }
-  return 0;
-}
-
-inline float nsCSSValue::GetPercentValue(void) const
-{
-  NS_ASSERTION((mUnit == eCSSUnit_Percent), "not a percent value");
-  if ((mUnit == eCSSUnit_Percent)) {
-    return mValue.mFloat;
-  }
-  return 0.0f;
-}
-
-inline float nsCSSValue::GetFloatValue(void) const
-{
-  NS_ASSERTION((eCSSUnit_Number <= mUnit), "not a float value");
-  if ((mUnit >= eCSSUnit_Number)) {
-    return mValue.mFloat;
-  }
-  return 0.0f;
-}
-
-inline nsAString& nsCSSValue::GetStringValue(nsAString& aBuffer) const
-{
-  NS_ASSERTION((eCSSUnit_String <= mUnit) && (mUnit <= eCSSUnit_Counters), "not a string value");
-  aBuffer.Truncate();
-  if ((eCSSUnit_String <= mUnit) && (mUnit <= eCSSUnit_Counters) && 
-      (nsnull != mValue.mString)) {
-    aBuffer.Append(mValue.mString);
-  }
-  return aBuffer;
-}
-
-inline nscolor nsCSSValue::GetColorValue(void) const
-{
-  NS_ASSERTION((mUnit == eCSSUnit_Color), "not a color value");
-  if (mUnit == eCSSUnit_Color) {
-    return mValue.mColor;
-  }
-  return NS_RGB(0,0,0);
-}
-
-inline PRBool nsCSSValue::operator!=(const nsCSSValue& aOther) const
-{
-  return PRBool(! ((*this) == aOther));
-}
-
-
-
 #endif /* nsCSSValue_h___ */
 
diff --git a/mozilla/layout/style/nsComputedDOMStyle.cpp b/mozilla/layout/style/nsComputedDOMStyle.cpp
index 7113e1befee..0d728a9a73b 100644
--- a/mozilla/layout/style/nsComputedDOMStyle.cpp
+++ b/mozilla/layout/style/nsComputedDOMStyle.cpp
@@ -339,7 +339,7 @@ nsComputedDOMStyle::GetBinding(nsIFrame *aFrame,
 
   GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display, aFrame);
 
-  if (display && !display->mBinding.IsEmpty()) {
+  if (display && display->mBinding) {
     val->SetURI(display->mBinding);
   } else {
     val->SetIdent(NS_LITERAL_STRING("none"));
@@ -1307,7 +1307,7 @@ nsComputedDOMStyle::GetListStyleImage(nsIFrame *aFrame,
   GetStyleData(eStyleStruct_List, (const nsStyleStruct*&)list, aFrame);
 
   if (list) {
-    if (list->mListStyleImage.IsEmpty()) {
+    if (!list->mListStyleImage) {
       val->SetIdent(NS_LITERAL_STRING("none"));
     } else {
       val->SetURI(list->mListStyleImage);
@@ -1741,7 +1741,7 @@ nsComputedDOMStyle::GetCursor(nsIFrame *aFrame,
   GetStyleData(eStyleStruct_UserInterface, (const nsStyleStruct*&)ui, aFrame);
 
   if (ui) {
-    if (!ui->mCursorImage.IsEmpty()) {
+    if (ui->mCursorImage) {
       val->SetURI(ui->mCursorImage);
     } else {
       if (ui->mCursor == NS_STYLE_CURSOR_AUTO) {
diff --git a/mozilla/layout/style/nsROCSSPrimitiveValue.cpp b/mozilla/layout/style/nsROCSSPrimitiveValue.cpp
index 75a1b521a10..6c1c1ace849 100644
--- a/mozilla/layout/style/nsROCSSPrimitiveValue.cpp
+++ b/mozilla/layout/style/nsROCSSPrimitiveValue.cpp
@@ -58,16 +58,20 @@ nsROCSSPrimitiveValue::~nsROCSSPrimitiveValue()
 }
 
 void
-nsROCSSPrimitiveValue::GetEscapedURI(PRUnichar *aURI, PRUnichar **aReturn)
+nsROCSSPrimitiveValue::GetEscapedURI(nsIURI *aURI, PRUnichar **aReturn)
 {
-  PRUint16 length = nsCRT::strlen(aURI);
+  nsCAutoString specUTF8;
+  aURI->GetSpec(specUTF8);
+  NS_ConvertUTF8toUCS2 spec(specUTF8);
+
+  PRUint16 length = spec.Length();
   PRUnichar *escaped = (PRUnichar *)nsMemory::Alloc(length * 2 * sizeof(PRUnichar) + sizeof(PRUnichar('\0')));
 
   if (escaped) {
     PRUnichar *ptr = escaped;
 
     for (PRUint16 i = 0; i < length; ++i) {
-      switch (aURI[i]) {
+      switch (spec[i]) {
         case ' ' : // space
         case '\t': // tab
         case '(' : // opening parenthesis
@@ -83,7 +87,7 @@ nsROCSSPrimitiveValue::GetEscapedURI(PRUnichar *aURI, PRUnichar **aReturn)
         default:
           break;
       }
-      *ptr++ = aURI[i];
+      *ptr++ = spec[i];
     }
     *ptr = 0;
   }
@@ -159,10 +163,16 @@ nsROCSSPrimitiveValue::GetCssText(nsAString& aCssText)
     case CSS_URI :
       {
         nsXPIDLString uri;
-        GetEscapedURI(mValue.mString, getter_Copies(uri));
-        tmpStr.Assign(NS_LITERAL_STRING("url(") +
-                      uri +
-                      NS_LITERAL_STRING(")"));
+        if (mValue.mURI) {
+          GetEscapedURI(mValue.mURI, getter_Copies(uri));
+          tmpStr.Assign(NS_LITERAL_STRING("url(") +
+                        uri +
+                        NS_LITERAL_STRING(")"));
+        } else {
+          // XXXldb Any better ideas?  It's good to have something that
+          // doesn't parse so that things round-trip "correctly".
+          tmpStr.Assign(NS_LITERAL_STRING("url(invalid-url:)"));
+        }
         break;
       }
     case CSS_PERCENTAGE :
@@ -401,9 +411,14 @@ nsROCSSPrimitiveValue::GetStringValue(nsAString& aReturn)
   switch (mType) {
     case CSS_IDENT:
     case CSS_STRING:
-    case CSS_URI:
       aReturn.Assign(mValue.mString);
       break;
+    case CSS_URI: {
+      nsCAutoString spec;
+      if (mValue.mURI)
+        mValue.mURI->GetSpec(spec);
+      CopyUTF8toUTF16(spec, aReturn);
+      } break;
     case CSS_ATTR:
     default:
       aReturn.Truncate();
diff --git a/mozilla/layout/style/nsROCSSPrimitiveValue.h b/mozilla/layout/style/nsROCSSPrimitiveValue.h
index b7f47a9caa8..d46528621f4 100644
--- a/mozilla/layout/style/nsROCSSPrimitiveValue.h
+++ b/mozilla/layout/style/nsROCSSPrimitiveValue.h
@@ -44,6 +44,7 @@
 #include "nsCoord.h"
 #include "nsUnitConversion.h"
 #include "nsReadableUtils.h"
+#include "nsIURI.h"
 
 #include "nsCOMPtr.h"
 #include "nsDOMError.h"
@@ -151,26 +152,12 @@ public:
     }
   }
 
-  void SetURI(const nsACString& aString)
+  void SetURI(nsIURI *aURI)
   {
     Reset();
-    mValue.mString = ToNewUnicode(aString);
-    if (mValue.mString) {
-      mType = CSS_URI;
-    } else {
-      mType = CSS_UNKNOWN;
-    }
-  }
-
-  void SetURI(const nsAString& aString)
-  {
-    Reset();
-    mValue.mString = ToNewUnicode(aString);
-    if (mValue.mString) {
-      mType = CSS_URI;
-    } else {
-      mType = CSS_UNKNOWN;
-    }
+    mValue.mURI = aURI;
+    NS_IF_ADDREF(mValue.mURI);
+    mType = CSS_URI;
   }
 
   void SetColor(nsIDOMRGBColor* aColor)
@@ -206,11 +193,13 @@ public:
     switch (mType) {
       case CSS_IDENT:
       case CSS_STRING:
-      case CSS_URI:
         NS_ASSERTION(mValue.mString, "Null string should never happen");
         nsMemory::Free(mValue.mString);
         mValue.mString = nsnull;
         break;
+      case CSS_URI:
+        NS_IF_RELEASE(mValue.mURI);
+        break;
       case CSS_RECT:
         NS_ASSERTION(mValue.mRect, "Null Rect should never happen");
         NS_RELEASE(mValue.mRect);
@@ -225,7 +214,7 @@ public:
   }
 
 private:
-  void GetEscapedURI(PRUnichar *aURI, PRUnichar **aReturn);
+  void GetEscapedURI(nsIURI *aURI, PRUnichar **aReturn);
 
   PRUint16 mType;
 
@@ -235,6 +224,7 @@ private:
     nsIDOMRGBColor* mColor;
     nsIDOMRect*     mRect;
     PRUnichar*      mString;
+    nsIURI*         mURI;
   } mValue;
   
   float mT2P;
diff --git a/mozilla/layout/style/nsRuleNode.cpp b/mozilla/layout/style/nsRuleNode.cpp
index 61bba67ac11..11d24f40a90 100644
--- a/mozilla/layout/style/nsRuleNode.cpp
+++ b/mozilla/layout/style/nsRuleNode.cpp
@@ -2321,7 +2321,7 @@ nsRuleNode::ComputeUserInterfaceData(nsStyleStruct* aStartData,
       ui->mCursor = NS_STYLE_CURSOR_AUTO;
     }
     else if (eCSSUnit_URL == list->mValue.GetUnit()) {
-      list->mValue.GetStringValue(ui->mCursorImage);
+      ui->mCursorImage = list->mValue.GetURLValue();
     }
     else if (eCSSUnit_Inherit == list->mValue.GetUnit()) {
       inherited = PR_TRUE;
@@ -2530,10 +2530,10 @@ nsRuleNode::ComputeDisplayData(nsStyleStruct* aStartStruct,
 
   // binding: url, none, inherit
   if (eCSSUnit_URL == displayData.mBinding.GetUnit()) {
-    displayData.mBinding.GetStringValue(display->mBinding);
+    display->mBinding = displayData.mBinding.GetURLValue();
   }
   else if (eCSSUnit_None == displayData.mBinding.GetUnit()) {
-    display->mBinding.Truncate();
+    display->mBinding = nsnull;
   }
   else if (eCSSUnit_Inherit == displayData.mBinding.GetUnit()) {
     inherited = PR_TRUE;
@@ -2926,11 +2926,11 @@ nsRuleNode::ComputeBackgroundData(nsStyleStruct* aStartStruct,
 
   // background-image: url, none, inherit
   if (eCSSUnit_URL == colorData.mBackImage.GetUnit()) {
-    colorData.mBackImage.GetStringValue(bg->mBackgroundImage);
+    bg->mBackgroundImage = colorData.mBackImage.GetURLValue();
     bg->mBackgroundFlags &= ~NS_STYLE_BG_IMAGE_NONE;
   }
   else if (eCSSUnit_None == colorData.mBackImage.GetUnit()) {
-    bg->mBackgroundImage.Truncate();
+    bg->mBackgroundImage = nsnull;
     bg->mBackgroundFlags |= NS_STYLE_BG_IMAGE_NONE;
   }
   else if (eCSSUnit_Inherit == colorData.mBackImage.GetUnit()) {
@@ -3448,10 +3448,10 @@ nsRuleNode::ComputeListData(nsStyleStruct* aStartStruct,
 
   // list-style-image: url, none, inherit
   if (eCSSUnit_URL == listData.mImage.GetUnit()) {
-    listData.mImage.GetStringValue(list->mListStyleImage);
+    list->mListStyleImage = listData.mImage.GetURLValue();
   }
   else if (eCSSUnit_None == listData.mImage.GetUnit()) {
-    list->mListStyleImage.Truncate();
+    list->mListStyleImage = nsnull;
   }
   else if (eCSSUnit_Inherit == listData.mImage.GetUnit()) {
     inherited = PR_TRUE;
@@ -3813,10 +3813,8 @@ nsRuleNode::ComputeContentData(nsStyleStruct* aStartStruct,
       inherited = PR_TRUE;
       count = parentContent->ContentCount();
       if (NS_SUCCEEDED(content->AllocateContents(count))) {
-        nsStyleContentType type;
         while (0 < count--) {
-          parentContent->GetContentAt(count, type, buffer);
-          content->SetContentAt(count, type, buffer);
+          content->ContentAt(count) = parentContent->ContentAt(count);
         }
       }
     }
@@ -3834,6 +3832,7 @@ nsRuleNode::ComputeContentData(nsStyleStruct* aStartStruct,
           const nsCSSValue& value = contentValue->mValue;
           nsCSSUnit unit = value.GetUnit();
           nsStyleContentType type;
+          nsStyleContentData &data = content->ContentAt(count++);
           switch (unit) {
             case eCSSUnit_String:   type = eStyleContentType_String;    break;
             case eCSSUnit_URL:      type = eStyleContentType_URL;       break;
@@ -3857,13 +3856,18 @@ nsRuleNode::ComputeContentData(nsStyleStruct* aStartStruct,
             default:
               NS_ERROR("bad content type");
           }
-          if (type < eStyleContentType_OpenQuote) {
+          data.mType = type;
+          if (type == eStyleContentType_URL) {
+            data.mContent.mURL = value.GetURLValue();
+            NS_IF_ADDREF(data.mContent.mURL);
+          }
+          else if (type < eStyleContentType_OpenQuote) {
             value.GetStringValue(buffer);
             Unquote(buffer);
-            content->SetContentAt(count++, type, buffer);
+            data.mContent.mString = nsCRT::strdup(buffer.get());
           }
           else {
-            content->SetContentAt(count++, type, nullStr);
+            data.mContent.mString = nsnull;
           }
           contentValue = contentValue->mNext;
         }
diff --git a/mozilla/layout/style/nsStyleStruct.cpp b/mozilla/layout/style/nsStyleStruct.cpp
index f6886c08c89..a4b9438d1e6 100644
--- a/mozilla/layout/style/nsStyleStruct.cpp
+++ b/mozilla/layout/style/nsStyleStruct.cpp
@@ -701,7 +701,6 @@ nsStyleList::nsStyleList()
 {
   mListStyleType = NS_STYLE_LIST_STYLE_BASIC;
   mListStylePosition = NS_STYLE_LIST_STYLE_POSITION_OUTSIDE;
-  mListStyleImage.Truncate();  
 }
 
 nsStyleList::~nsStyleList() 
@@ -709,10 +708,10 @@ nsStyleList::~nsStyleList()
 }
 
 nsStyleList::nsStyleList(const nsStyleList& aSource)
+  : mListStyleType(aSource.mListStyleType),
+    mListStylePosition(aSource.mListStylePosition),
+    mListStyleImage(aSource.mListStyleImage)
 {
-  mListStyleType = aSource.mListStyleType;
-  mListStylePosition = aSource.mListStylePosition;
-  mListStyleImage = aSource.mListStyleImage;
 }
 
 nsChangeHint nsStyleList::CalcDifference(const nsStyleList& aOther) const
@@ -1192,7 +1191,7 @@ nsStyleContent::nsStyleContent(const nsStyleContent& aSource)
   PRUint32 index;
   if (NS_SUCCEEDED(AllocateContents(aSource.ContentCount()))) {
     for (index = 0; index < mContentCount; index++) {
-      aSource.GetContentAt(index, mContents[index].mType, mContents[index].mContent);
+      ContentAt(index) = aSource.ContentAt(index);
     }
   }
 
@@ -1219,8 +1218,7 @@ nsChangeHint nsStyleContent::CalcDifference(const nsStyleContent& aOther) const
         (mResetCount == aOther.mResetCount)) {
       PRUint32 ix = mContentCount;
       while (0 < ix--) {
-        if ((mContents[ix].mType != aOther.mContents[ix].mType) || 
-            (mContents[ix].mContent != aOther.mContents[ix].mContent)) {
+        if (mContents[ix] != aOther.mContents[ix]) {
           // Unfortunately we need to reframe here; a simple reflow
           // will not pick up different text or different image URLs,
           // since we set all that up in the CSSFrameConstructor
diff --git a/mozilla/layout/style/nsStyleStruct.h b/mozilla/layout/style/nsStyleStruct.h
index 34381e87c16..c10c15bc946 100644
--- a/mozilla/layout/style/nsStyleStruct.h
+++ b/mozilla/layout/style/nsStyleStruct.h
@@ -52,6 +52,7 @@
 #include "nsIPresShell.h"
 #include "nsCOMPtr.h"
 #include "nsILanguageAtom.h"
+#include "nsIURI.h"
 
 class nsIFrame;
 
@@ -183,7 +184,7 @@ struct nsStyleBackground : public nsStyleStruct {
     mBackgroundYPosition;         // [reset]
 
   nscolor mBackgroundColor;       // [reset]
-  nsString mBackgroundImage;      // [reset] absolute url string
+  nsCOMPtr<nsIURI> mBackgroundImage; // [reset]
 
   PRBool IsTransparent() const
   {
@@ -586,7 +587,7 @@ struct nsStyleList : public nsStyleStruct {
   
   PRUint8   mListStyleType;             // [inherited] See nsStyleConsts.h
   PRUint8   mListStylePosition;         // [inherited] 
-  nsString  mListStyleImage;            // [inherited] absolute url string
+  nsCOMPtr<nsIURI> mListStyleImage;     // [inherited]
   nsRect        mImageRegion;           // [inherited] the rect to use within an image  
 };
 
@@ -732,7 +733,7 @@ struct nsStyleDisplay : public nsStyleStruct {
 
   nsChangeHint CalcDifference(const nsStyleDisplay& aOther) const;
   
-  nsString  mBinding;           // [reset] absolute url string
+  nsCOMPtr<nsIURI> mBinding;    // [reset]
 #if 0
   // XXX This is how it is defined in the CSS2 spec, but the errata
   // changed it to be consistent with the positioning draft and how
@@ -834,7 +835,48 @@ enum nsStyleContentType {
 
 struct nsStyleContentData {
   nsStyleContentType  mType;
-  nsString            mContent;
+  union {
+    PRUnichar *mString;
+    nsIURI    *mURL;
+  } mContent;
+
+  ~nsStyleContentData() {
+    if (mType == eStyleContentType_URL) {
+      NS_IF_RELEASE(mContent.mURL);
+    } else if (mContent.mString) {
+      nsCRT::free(mContent.mString);
+    }
+  }
+
+  nsStyleContentData& operator=(const nsStyleContentData& aOther) {
+    mType = aOther.mType;
+    if (mType == eStyleContentType_URL) {
+      mContent.mURL = aOther.mContent.mURL;
+      NS_IF_ADDREF(mContent.mURL);
+    } else if (aOther.mContent.mString) {
+      mContent.mString = nsCRT::strdup(aOther.mContent.mString);
+    } else {
+      mContent.mString = nsnull;
+    }
+    return *this;
+  }
+
+  PRBool operator==(const nsStyleContentData& aOther) {
+    if (mType != aOther.mType)
+      return PR_FALSE;
+    if (mType == eStyleContentType_URL) {
+      PRBool eq;
+      return mContent.mURL == aOther.mContent.mURL ||  // handles null==null
+             (mContent.mURL && aOther.mContent.mURL &&
+              NS_SUCCEEDED(mContent.mURL->Equals(aOther.mContent.mURL, &eq)) &&
+              eq);
+    }
+    return mContent.mString == aOther.mContent.mString;
+  }
+
+  PRBool operator!=(const nsStyleContentData& aOther) {
+    return !(*this == aOther);
+  }
 };
 
 struct nsStyleCounterData {
@@ -926,13 +968,15 @@ struct nsStyleContent: public nsStyleStruct {
   nsChangeHint CalcDifference(const nsStyleContent& aOther) const;
 
   PRUint32  ContentCount(void) const  { return mContentCount; } // [reset]
-  nsresult  GetContentAt(PRUint32 aIndex, nsStyleContentType& aType, nsString& aContent) const {
-    if (aIndex < mContentCount) {
-      aType = mContents[aIndex].mType;
-      aContent = mContents[aIndex].mContent;
-      return NS_OK;
-    }
-    return NS_ERROR_ILLEGAL_VALUE;
+
+  const nsStyleContentData& ContentAt(PRUint32 aIndex) const {
+    NS_ASSERTION(aIndex < mContentCount, "out of range");
+    return mContents[aIndex];
+  }
+
+  nsStyleContentData& ContentAt(PRUint32 aIndex) {
+    NS_ASSERTION(aIndex < mContentCount, "out of range");
+    return mContents[aIndex];
   }
 
   nsresult  AllocateContents(PRUint32 aCount) {
@@ -950,20 +994,6 @@ struct nsStyleContent: public nsStyleStruct {
     return NS_OK;
   }
 
-  nsresult  SetContentAt(PRUint32 aIndex, nsStyleContentType aType, const nsString& aContent) {
-    if (aIndex < mContentCount) {
-      mContents[aIndex].mType = aType;
-      if (aType < eStyleContentType_OpenQuote) {
-        mContents[aIndex].mContent = aContent;
-      }
-      else {
-        mContents[aIndex].mContent.Truncate();
-      }
-      return NS_OK;
-    }
-    return NS_ERROR_ILLEGAL_VALUE;
-  }
-
   PRUint32  CounterIncrementCount(void) const { return mIncrementCount; }  // [reset]
   nsresult  GetCounterIncrementAt(PRUint32 aIndex, nsString& aCounter, PRInt32& aIncrement) const {
     if (aIndex < mIncrementCount) {
@@ -1094,7 +1124,7 @@ struct nsStyleUserInterface: public nsStyleStruct {
   PRUint8   mUserFocus;       // [inherited] (auto-select)
   
   PRUint8 mCursor;                // [inherited] See nsStyleConsts.h NS_STYLE_CURSOR_*
-  nsString mCursorImage;          // [inherited] url string
+  nsCOMPtr<nsIURI> mCursorImage; // [inherited] url string
 };
 
 struct nsStyleXUL : public nsStyleStruct {
diff --git a/mozilla/layout/xul/base/src/nsImageBoxFrame.cpp b/mozilla/layout/xul/base/src/nsImageBoxFrame.cpp
index 58e318c9934..c814ac0a04b 100644
--- a/mozilla/layout/xul/base/src/nsImageBoxFrame.cpp
+++ b/mozilla/layout/xul/base/src/nsImageBoxFrame.cpp
@@ -357,12 +357,17 @@ void
 nsImageBoxFrame::GetImageSource()
 {
   // get the new image src
-  mContent->GetAttr(kNameSpaceID_None, nsHTMLAtoms::src, mSrc);
-
-  // if the new image is empty
-  if (mSrc.IsEmpty()) {
-    mUseSrcAttr = PR_FALSE;
-
+  nsAutoString src;
+  mContent->GetAttr(kNameSpaceID_None, nsHTMLAtoms::src, src);
+  mUseSrcAttr = !src.IsEmpty();
+  if (mUseSrcAttr) {
+    nsCOMPtr<nsIURI> baseURI;
+    if (mContent) {
+      mContent->GetBaseURL(getter_AddRefs(baseURI));
+    }
+    // XXX origin charset needed
+    NS_NewURI(getter_AddRefs(mURI), src, nsnull, baseURI);
+  } else {
     // Only get the list-style-image if we aren't being drawn
     // by a native theme.
     const nsStyleDisplay* disp = GetStyleDisplay();
@@ -371,14 +376,8 @@ nsImageBoxFrame::GetImageSource()
       return;
 
     // get the list-style-image
-    const nsStyleList* myList = GetStyleList();
-  
-    if (!myList->mListStyleImage.IsEmpty()) {
-      mSrc = myList->mListStyleImage;
-    }
+    mURI = GetStyleList()->mListStyleImage;
   }
-  else
-    mUseSrcAttr = PR_TRUE;
 }
 
 void
@@ -414,7 +413,7 @@ nsImageBoxFrame::UpdateImage(nsIPresContext*  aPresContext, PRBool& aResize)
   aResize = PR_FALSE;
 
   // get the new image src
-  if (mSrc.IsEmpty()) {
+  if (!mURI) {
     mSizeFrozen = PR_TRUE;
     mHasImage = PR_FALSE;
     aResize = PR_TRUE;
@@ -427,21 +426,7 @@ nsImageBoxFrame::UpdateImage(nsIPresContext*  aPresContext, PRBool& aResize)
     return;
   }
 
-  nsCOMPtr<nsIURI> baseURI;
-  if (mContent) {
-    mContent->GetBaseURL(getter_AddRefs(baseURI));
-  }
-  nsCOMPtr<nsIURI> srcURI;
-  nsresult rv = NS_NewURI(getter_AddRefs(srcURI), mSrc, nsnull, baseURI);
-
-  if (NS_FAILED(rv)) {
-    if (mImageRequest) {
-      mImageRequest->Cancel(NS_ERROR_FAILURE);
-      mImageRequest = nsnull;
-    }
-    return;
-  }
-
+  nsresult rv;
   if (mImageRequest) {
     nsCOMPtr<nsIURI> requestURI;
     rv = mImageRequest->GetURI(getter_AddRefs(requestURI));
@@ -449,9 +434,8 @@ nsImageBoxFrame::UpdateImage(nsIPresContext*  aPresContext, PRBool& aResize)
     if (NS_FAILED(rv) || !requestURI) return;
 
     PRBool eq;
-    requestURI->Equals(srcURI, &eq);
     // if the source uri and the current one are the same, return
-    if (eq)
+    if (NS_SUCCEEDED(requestURI->Equals(mURI, &eq)) && eq)
       return;
   }
 
@@ -481,7 +465,7 @@ nsImageBoxFrame::UpdateImage(nsIPresContext*  aPresContext, PRBool& aResize)
   }
 
   // XXX: initialDocumentURI is NULL!
-  il->LoadImage(srcURI, nsnull, documentURI, loadGroup, mListener, doc,
+  il->LoadImage(mURI, nsnull, documentURI, loadGroup, mListener, doc,
                 mLoadFlags, nsnull, nsnull, getter_AddRefs(mImageRequest));
 
   aResize = PR_TRUE;
@@ -587,11 +571,13 @@ nsImageBoxFrame::DidSetStyleContext( nsIPresContext* aPresContext )
     return NS_OK;
 
   // If list-style-image changes, we have a new image.
-  nsAutoString newSrc;
-  if (myList->mListStyleImage.Equals(mSrc))
+  nsIURI *newURI = myList->mListStyleImage;
+  PRBool equal;
+  if (newURI == mURI ||   // handles null==null
+      (newURI && mURI && NS_SUCCEEDED(newURI->Equals(mURI, &equal)) && equal))
     return NS_OK;
 
-  mSrc = myList->mListStyleImage;
+  mURI = newURI;
 
   PRBool aResize;
   UpdateImage(aPresContext, aResize);
diff --git a/mozilla/layout/xul/base/src/nsImageBoxFrame.h b/mozilla/layout/xul/base/src/nsImageBoxFrame.h
index b52847dd260..faa06453159 100644
--- a/mozilla/layout/xul/base/src/nsImageBoxFrame.h
+++ b/mozilla/layout/xul/base/src/nsImageBoxFrame.h
@@ -146,7 +146,7 @@ private:
   nsCOMPtr<imgIRequest> mImageRequest;
   nsCOMPtr<imgIDecoderObserver> mListener;
 
-  nsString mSrc; // The raw image source.
+  nsCOMPtr<nsIURI> mURI; // The URI of the image.
 
   PRPackedBool mUseSrcAttr; // Whether or not the image src comes from an attribute.
   PRPackedBool mSizeFrozen;
diff --git a/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp b/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp
index 3ca032018c2..9e1bf4ed3bb 100644
--- a/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp
+++ b/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp
@@ -1878,23 +1878,22 @@ nsTreeBodyFrame::GetImage(PRInt32 aRowIndex, const PRUnichar* aColID, PRBool aUs
 {
   *aResult = nsnull;
 
-  const nsAString* imagePtr;
   nsAutoString imageSrc;
   mView->GetImageSrc(aRowIndex, aColID, imageSrc);
   if (!aUseContext && !imageSrc.IsEmpty()) {
-    imagePtr = &imageSrc;
     aAllowImageRegions = PR_FALSE;
   }
   else {
     // Obtain the URL from the style context.
     aAllowImageRegions = PR_TRUE;
-    const nsStyleList* myList = aStyleContext->GetStyleList();
-    if (!myList->mListStyleImage.IsEmpty())
-      imagePtr = &myList->mListStyleImage;
-    else
+    nsIURI* uri = aStyleContext->GetStyleList()->mListStyleImage;
+    if (!uri)
       return NS_OK;
+    nsCAutoString spec;
+    uri->GetSpec(spec);
+    CopyUTF8toUTF16(spec, imageSrc);
   }
-  nsStringKey key(*imagePtr);
+  nsStringKey key(imageSrc);
 
   if (mImageCache) {
     // Look the image up in our cache.
@@ -1939,7 +1938,8 @@ nsTreeBodyFrame::GetImage(PRInt32 aRowIndex, const PRUnichar* aColID, PRBool aUs
     mContent->GetBaseURL(getter_AddRefs(baseURI));
 
     nsCOMPtr<nsIURI> srcURI;
-    NS_NewURI(getter_AddRefs(srcURI), *imagePtr, nsnull, baseURI);
+    // XXX origin charset needed
+    NS_NewURI(getter_AddRefs(srcURI), imageSrc, nsnull, baseURI);
     if (!srcURI)
       return NS_ERROR_FAILURE;
     nsCOMPtr<imgIRequest> imageRequest;
@@ -3324,7 +3324,7 @@ nsTreeBodyFrame::ScrollInternal(PRInt32 aRow)
   nscoord rowHeightAsPixels = NSToCoordRound((float)mRowHeight*t2p);
 
   // See if we have a background image.  If we do, then we cannot blit.
-  PRBool hasBackground = !GetStyleBackground()->mBackgroundImage.IsEmpty();
+  PRBool hasBackground = GetStyleBackground()->mBackgroundImage != nsnull;
 
   PRInt32 absDelta = PR_ABS(delta);
   if (hasBackground || absDelta*mRowHeight >= mRect.height)