Enable removing uploads to evicted textures from texture upload queues.

cc/LayerTextureUpdater.h

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 #ifndef LayerTextureUpdater_h
 #define LayerTextureUpdater_h
 
 #if USE(ACCELERATED_COMPOSITING)
 
@@ skipping 12 matching lines @@
 public:
     // Allows texture uploaders to store per-tile resources.
     class Texture {
     public:
         virtual ~Texture() { }
 
         CCPrioritizedTexture* texture() { return m_texture.get(); }
         void swapTextureWith(OwnPtr<CCPrioritizedTexture>& texture) { m_texture.swap(texture); }
         virtual void prepareRect(const IntRect& /* sourceRect */, CCRenderingStats&) { }
         virtual void updateRect(CCResourceProvider*, const IntRect& sourceRect, const IntSize& destOffset) = 0;
+        virtual bool backingResourceWasEvicted() const { return m_texture->backingResourceWasEvicted(); }
     protected:
         explicit Texture(PassOwnPtr<CCPrioritizedTexture> texture) : m_texture(texture) { }
 
     private:
         OwnPtr<CCPrioritizedTexture> m_texture;
     };
 
     LayerTextureUpdater()
     {
         turnOffVerifier(); // In the component build we don't have WTF threading initialized in this DLL so the thread verifier explodes.
@@ skipping 16 matching lines @@
     // then this region should be ignored in preference for the entire layer's area.
     virtual void prepareToUpdate(const IntRect& contentRect, const IntSize& tileSize, float contentsWidthScale, float contentsHeightScale, IntRect& resultingOpaqueRect, CCRenderingStats&) { }
 
     // Set true by the layer when it is known that the entire output is going to be opaque.
     virtual void setOpaque(bool) { }
 };
 
 } // namespace cc
 #endif // USE(ACCELERATED_COMPOSITING)
 #endif // LayerTextureUpdater_h