Merge 136558

Source/WebCore/css/CSSCrossfadeValue.cpp

Index: Source/WebCore/css/CSSCrossfadeValue.cpp
===================================================================
--- Source/WebCore/css/CSSCrossfadeValue.cpp	(revision 137663)
+++ Source/WebCore/css/CSSCrossfadeValue.cpp	(working copy)
@@ -128,14 +128,26 @@
 
 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);
 }