diff --git a/content/base/public/nsContentUtils.h b/content/base/public/nsContentUtils.h
index b5faf23d7c89..7da4116c9828 100644
--- a/content/base/public/nsContentUtils.h
+++ b/content/base/public/nsContentUtils.h
@@ -401,6 +401,16 @@ public:
    */
   static PRBool IsHTMLWhitespace(PRUnichar aChar);
 
+  /**
+   * Parse a margin string of format 'top, right, bottom, left' into
+   * an nsIntMargin.
+   *
+   * @param aString the string to parse
+   * @param aResult the resulting integer
+   * @return whether the value could be parsed
+   */
+  static PRBool ParseIntMarginValue(const nsAString& aString, nsIntMargin& aResult);
+
   static void Shutdown();
 
   /**
diff --git a/content/base/public/nsIContentUtils.h b/content/base/public/nsIContentUtils.h
index d2c47f9b6d8a..196d6bbd6715 100644
--- a/content/base/public/nsIContentUtils.h
+++ b/content/base/public/nsIContentUtils.h
@@ -39,11 +39,13 @@
 
 #include "nsIDocumentLoaderFactory.h"
 #include "nsCOMPtr.h"
+#include "nsAString.h"
+#include "nsMargin.h"
 
-// C4EA618E-A3D9-4524-8EEA-E92F26FC44DB
+// {3682DD99-8560-44f4-9B8F-CCCE9D7B96FB}
 #define NS_ICONTENTUTILS_IID \
-{ 0xC4EA618E, 0xA3D9, 0x4524, \
-  { 0x8E, 0xEA, 0xE9, 0x2F, 0x26, 0xFC, 0x44, 0xDB } }
+{ 0x3682dd99, 0x8560, 0x44f4, \
+  { 0x9b, 0x8f, 0xcc, 0xce, 0x9d, 0x7b, 0x96, 0xfb } }
 
 class nsIContentUtils : public nsISupports
 {
@@ -52,6 +54,7 @@ public:
     NS_DECL_ISUPPORTS
 
     virtual PRBool IsSafeToRunScript();
+    virtual PRBool ParseIntMarginValue(const nsAString& aString, nsIntMargin& result);
 
     enum ContentViewerType
     {
diff --git a/content/base/src/nsAttrValue.cpp b/content/base/src/nsAttrValue.cpp
index c73209642898..5546dafa0d38 100644
--- a/content/base/src/nsAttrValue.cpp
+++ b/content/base/src/nsAttrValue.cpp
@@ -92,6 +92,12 @@ nsAttrValue::nsAttrValue(nsISVGValue* aValue)
 }
 #endif
 
+nsAttrValue::nsAttrValue(const nsIntMargin& aValue)
+    : mBits(0)
+{
+  SetTo(aValue);
+}
+
 nsAttrValue::~nsAttrValue()
 {
   ResetIfSet();
@@ -259,6 +265,12 @@ nsAttrValue::SetTo(const nsAttrValue& aOther)
       cont->mFloatValue = otherCont->mFloatValue;
       break;
     }
+    case eIntMarginValue:
+    {
+      if (otherCont->mIntMargin)
+        cont->mIntMargin = new nsIntMargin(*otherCont->mIntMargin);
+      break;
+    }
     default:
     {
       NS_NOTREACHED("unknown type stored in MiscContainer");
@@ -320,6 +332,16 @@ nsAttrValue::SetTo(nsISVGValue* aValue)
 }
 #endif
 
+void
+nsAttrValue::SetTo(const nsIntMargin& aValue)
+{
+  if (EnsureEmptyMiscContainer()) {
+    MiscContainer* cont = GetMiscContainer();
+    cont->mIntMargin = new nsIntMargin(aValue);
+    cont->mType = eIntMarginValue;
+  }
+}
+
 void
 nsAttrValue::SwapValueWith(nsAttrValue& aOther)
 {
@@ -585,6 +607,10 @@ nsAttrValue::HashValue() const
       // XXX this is crappy, but oh well
       return cont->mFloatValue;
     }
+    case eIntMarginValue:
+    {
+      return NS_PTR_TO_INT32(cont->mIntMargin);
+    }
     default:
     {
       NS_NOTREACHED("unknown type stored in MiscContainer");
@@ -687,6 +713,10 @@ nsAttrValue::Equals(const nsAttrValue& aOther) const
     {
       return thisCont->mFloatValue == otherCont->mFloatValue;
     }
+    case eIntMarginValue:
+    {
+      return thisCont->mIntMargin == otherCont->mIntMargin;
+    }
     default:
     {
       NS_NOTREACHED("unknown type stored in MiscContainer");
@@ -1204,6 +1234,26 @@ PRBool nsAttrValue::ParseFloatValue(const nsAString& aString)
   return PR_FALSE;
 }
 
+PRBool
+nsAttrValue::ParseIntMarginValue(const nsAString& aString)
+{
+  ResetIfSet();
+
+  nsIntMargin margins;
+  if (!nsContentUtils::ParseIntMarginValue(aString, margins))
+    return PR_FALSE;
+
+  if (EnsureEmptyMiscContainer()) {
+    MiscContainer* cont = GetMiscContainer();
+    cont->mIntMargin = new nsIntMargin(margins);
+    cont->mType = eIntMarginValue;
+    SetMiscAtomOrString(&aString);
+    return PR_TRUE;
+  }
+
+  return PR_FALSE;
+}
+
 void
 nsAttrValue::SetMiscAtomOrString(const nsAString* aValue)
 {
@@ -1269,6 +1319,11 @@ nsAttrValue::EnsureEmptyMiscContainer()
         break;
       }
 #endif
+      case eIntMarginValue:
+      {
+        delete cont->mIntMargin;
+        break;
+      }
       default:
       {
         break;
diff --git a/content/base/src/nsAttrValue.h b/content/base/src/nsAttrValue.h
index 1ee64aee1420..d08eacf89463 100644
--- a/content/base/src/nsAttrValue.h
+++ b/content/base/src/nsAttrValue.h
@@ -49,6 +49,7 @@
 #include "nsStringBuffer.h"
 #include "nsColor.h"
 #include "nsCaseTreatment.h"
+#include "nsMargin.h"
 
 typedef PRUptrdiff PtrBits;
 class nsAString;
@@ -98,6 +99,7 @@ public:
 #ifdef MOZ_SVG
   explicit nsAttrValue(nsISVGValue* aValue);
 #endif
+  explicit nsAttrValue(const nsIntMargin& aValue);
   ~nsAttrValue();
 
   static nsresult Init();
@@ -120,6 +122,7 @@ public:
     ,eSVGValue =    0x12
 #endif
     ,eFloatValue  = 0x13
+    ,eIntMarginValue = 0x14
   };
 
   ValueType Type() const;
@@ -133,6 +136,7 @@ public:
 #ifdef MOZ_SVG
   void SetTo(nsISVGValue* aValue);
 #endif
+  void SetTo(const nsIntMargin& aValue);
 
   void SwapValueWith(nsAttrValue& aOther);
 
@@ -153,6 +157,7 @@ public:
   inline nsISVGValue* GetSVGValue() const;
 #endif
   inline float GetFloatValue() const;
+  PRBool GetIntMarginValue(nsIntMargin& aMargin) const;
 
   /**
    * Returns the string corresponding to the stored enum value.
@@ -297,6 +302,15 @@ public:
    */
   PRBool ParseLazyURIValue(const nsAString& aString);
 
+  /**
+   * Parse a margin string of format 'top, right, bottom, left' into
+   * an nsIntMargin.
+   *
+   * @param aString the string to parse
+   * @return whether the value could be parsed
+   */
+  PRBool ParseIntMarginValue(const nsAString& aString);
+
 private:
   // These have to be the same as in ValueType
   enum ValueBaseType {
@@ -325,6 +339,7 @@ private:
       nsISVGValue* mSVGValue;
 #endif
       float mFloatValue;
+      nsIntMargin* mIntMargin;
     };
   };
 
@@ -442,6 +457,17 @@ nsAttrValue::GetFloatValue() const
   return GetMiscContainer()->mFloatValue;
 }
 
+inline PRBool
+nsAttrValue::GetIntMarginValue(nsIntMargin& aMargin) const
+{
+  NS_PRECONDITION(Type() == eIntMarginValue, "wrong type");
+  nsIntMargin* m = GetMiscContainer()->mIntMargin;
+  if (!m)
+    return PR_FALSE;
+  aMargin = *m;
+  return PR_TRUE;
+}
+
 inline nsAttrValue::ValueBaseType
 nsAttrValue::BaseType() const
 {
diff --git a/content/base/src/nsContentUtils.cpp b/content/base/src/nsContentUtils.cpp
index bb315efad4c4..0ab80be58ccb 100644
--- a/content/base/src/nsContentUtils.cpp
+++ b/content/base/src/nsContentUtils.cpp
@@ -924,6 +924,53 @@ nsContentUtils::IsHTMLWhitespace(PRUnichar aChar)
          aChar == PRUnichar(0x0020);
 }
 
+/* static */
+PRBool
+nsContentUtils::ParseIntMarginValue(const nsAString& aString, nsIntMargin& result)
+{
+  nsAutoString marginStr(aString);
+  marginStr.CompressWhitespace(PR_TRUE, PR_TRUE);
+  if (marginStr.IsEmpty()) {
+    return PR_FALSE;
+  }
+
+  PRInt32 start = 0, end = 0;
+  for (int count = 0; count < 4; count++) {
+    if (end >= marginStr.Length())
+      return PR_FALSE;
+
+    // top, right, bottom, left
+    if (count < 3)
+      end = Substring(marginStr, start).FindChar(',');
+    else
+      end = Substring(marginStr, start).Length();
+
+    if (end <= 0)
+      return PR_FALSE;
+
+    PRInt32 ec, val = 
+      nsString(Substring(marginStr, start, end)).ToInteger(&ec);
+    if (NS_FAILED(ec))
+      return PR_FALSE;
+
+    switch(count) {
+      case 0:
+        result.top = val;
+      break;
+      case 1:
+        result.right = val;
+      break;
+      case 2:
+        result.bottom = val;
+      break;
+      case 3:
+        result.left = val;
+      break;
+    }
+    start += end + 1;
+  }
+  return PR_TRUE;
+}
 
 /* static */
 void
@@ -6115,6 +6162,12 @@ nsIContentUtils::IsSafeToRunScript()
   return nsContentUtils::IsSafeToRunScript();
 }
 
+PRBool
+nsIContentUtils::ParseIntMarginValue(const nsAString& aString, nsIntMargin& result)
+{
+  return nsContentUtils::ParseIntMarginValue(aString, result);
+}
+
 already_AddRefed<nsIDocumentLoaderFactory>
 nsIContentUtils::FindInternalContentViewer(const char* aType,
                                            ContentViewerType* aLoaderType)