Bug 268513 overflow:scroll causes memory growth

r=dbaron, sr=jst

layout/base/nsPresShell.cpp

@@ -3024,6 +3024,9 @@ PresShell::NotifyDestroyingFrame(nsIFrame* aFrame)
 
     // Remove frame properties
     mPresContext->PropertyTable()->DeleteAllPropertiesFor(aFrame);
+
+    // Clear anonymous content if any
+    SetAnonymousContentFor(aFrame->GetContent(), nsnull);
   }
 
   return NS_OK;
@@ -4633,7 +4636,10 @@ PresShell::SetAnonymousContentFor(nsIContent* aContent, nsISupportsArray* aAnony
           continue;
         
         content->SetDocument(nsnull, PR_TRUE, PR_TRUE);
+        nsCOMPtr<nsISupports> old_ref = mDocument->RemoveReference(content);
       }
+
+      mAnonymousContentTable->Remove(&key);
     }
   }