Keeping track of descendants that draw content instead of recalcualting

cc/layers/ui_resource_layer.h

Index: cc/layers/ui_resource_layer.h
diff --git a/cc/layers/ui_resource_layer.h b/cc/layers/ui_resource_layer.h
index d99c073a6dbd8bf16392361b8fdeefc4ed1fb22d..8e278a97bc601f1b8ef5c9795ca3966812a4c658 100644
--- a/cc/layers/ui_resource_layer.h
+++ b/cc/layers/ui_resource_layer.h
@@ -20,8 +20,6 @@ class CC_EXPORT UIResourceLayer : public Layer {
  public:
   static scoped_refptr<UIResourceLayer> Create();
 
-  virtual bool DrawsContent() const OVERRIDE;
-
   virtual void PushPropertiesTo(LayerImpl* layer) OVERRIDE;
 
   virtual void SetLayerTreeHost(LayerTreeHost* host) OVERRIDE;
@@ -51,6 +49,8 @@ class CC_EXPORT UIResourceLayer : public Layer {
   UIResourceLayer();
   virtual ~UIResourceLayer();
 
+  virtual bool HasDrawableContent() const OVERRIDE;
+
   scoped_ptr<UIResourceHolder> ui_resource_holder_;
   SkBitmap bitmap_;