Merge 136558

Source/WebCore/css/CSSCrossfadeValue.cpp

 /*
  * Copyright (C) 2011 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 110 matching lines @@
         fromImageSize.height() * inversePercentage + toImageSize.height() * percentage);
 }
 
 bool CSSCrossfadeValue::isPending() const
 {
     return subimageIsPending(m_fromValue.get()) || subimageIsPending(m_toValue.get());
 }
 
 void CSSCrossfadeValue::loadSubimages(CachedResourceLoader* cachedResourceLoader)
 {
+    CachedResourceHandle<CachedImage> oldCachedFromImage = m_cachedFromImage;
+    CachedResourceHandle<CachedImage> oldCachedToImage = m_cachedToImage;
+
     m_cachedFromImage = cachedImageForCSSValue(m_fromValue.get(), cachedResourceLoader);
     m_cachedToImage = cachedImageForCSSValue(m_toValue.get(), cachedResourceLoader);
 
-    if (m_cachedFromImage)
-        m_cachedFromImage->addClient(&m_crossfadeSubimageObserver);
-    if (m_cachedToImage)
-        m_cachedToImage->addClient(&m_crossfadeSubimageObserver);
+    if (m_cachedFromImage != oldCachedFromImage) {
+        if (oldCachedFromImage)
+            oldCachedFromImage->removeClient(&m_crossfadeSubimageObserver);
+        if (m_cachedFromImage)
+            m_cachedFromImage->addClient(&m_crossfadeSubimageObserver);
+    }
+
+    if (m_cachedToImage != oldCachedToImage) {
+        if (oldCachedToImage)
+            oldCachedToImage->removeClient(&m_crossfadeSubimageObserver);
+        if (m_cachedToImage)
+            m_cachedToImage->addClient(&m_crossfadeSubimageObserver);
+    }
 
     m_crossfadeSubimageObserver.setReady(true);
 }
 
 void CSSCrossfadeValue::reportDescendantMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
 {
     MemoryClassInfo info(memoryObjectInfo, this, WebCoreMemoryTypes::CSS);
     CSSImageGeneratorValue::reportBaseClassMemoryUsage(memoryObjectInfo);
     info.addMember(m_fromValue);
     info.addMember(m_toValue);
@@ skipping 45 matching lines @@
 bool CSSCrossfadeValue::hasFailedOrCanceledSubresources() const
 {
     if (m_cachedFromImage && m_cachedFromImage->loadFailedOrCanceled())
         return true;
     if (m_cachedToImage && m_cachedToImage->loadFailedOrCanceled())
         return true;
     return false;
 }
 
 } // namespace WebCore