Do image scaling on the GPU (bug 650988, r=roc,cjones).

layout/generic/nsImageFrame.h

@@ -410,13 +410,23 @@ public:
   }
   virtual void Paint(nsDisplayListBuilder* aBuilder,
                      nsRenderingContext* aCtx);
- 
+
   /**
    * Returns an ImageContainer for this image if the image type
    * supports it (TYPE_RASTER only).
    */
   already_AddRefed<ImageContainer> GetContainer();
-  
+
+  gfxRect GetDestRect();
+
+  virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
+                                   LayerManager* aManager,
+                                   const ContainerParameters& aParameters);
+
+  virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
+                                             LayerManager* aManager,
+                                             const ContainerParameters& aContainerParameters);
+
   /**
    * Configure an ImageLayer for this display item.
    * Set the required filter and scaling transform.