Allow eviction of ImageBitmaps that are created from ImageElements.

Source/core/loader/cache/CachedResource.h

Index: Source/core/loader/cache/CachedResource.h
diff --git a/Source/core/loader/cache/CachedResource.h b/Source/core/loader/cache/CachedResource.h
index e78d90364d3f16c1314c4fe448b17308a075e32b..03a7d8b7deca96ebba6dc5d3da8b39f5da3581ad 100644
--- a/Source/core/loader/cache/CachedResource.h
+++ b/Source/core/loader/cache/CachedResource.h
@@ -80,7 +80,13 @@ public:
         DecodeError
     };
 
-    CachedResource(const ResourceRequest&, Type);
+    enum DecodeCachePriority {

[Justin Novosad, 2013/07/19 21:09:53]

I'd call this just Priority.

+        DecodeCachePriorityLow = 0,
+        DecodeCachePriorityMedium,
+        DecodeCachePriorityHigh
+    };
+
+    CachedResource(const ResourceRequest&, Type, DecodeCachePriority = DecodeCachePriorityMedium);
     virtual ~CachedResource();
 
     virtual void load(CachedResourceLoader*, const ResourceLoaderOptions&);
@@ -169,6 +175,8 @@ public:
     void setInCache(bool inCache) { m_inCache = inCache; }
     bool inCache() const { return m_inCache; }
     
+    void setDecodeCachePriority(DecodeCachePriority priority) { m_decodeCachePriority = priority; }
+    DecodeCachePriority decodeCachePriority() { return m_decodeCachePriority; }
     bool inLiveDecodedResourcesList() { return m_inLiveDecodedResourcesList; }
     
     void clearLoader();
@@ -317,6 +325,7 @@ private:
 
     unsigned m_preloadResult : 2; // PreloadResult
 
+    DecodeCachePriority m_decodeCachePriority;

[Justin Novosad, 2013/07/19 21:09:53]

Put ": 2" at the end.

     bool m_inLiveDecodedResourcesList : 1;
     bool m_requestedFromNetworkingLayer : 1;