Keeping track of descendants that draw content instead of recalcualting

cc/layers/surface_layer.h

Index: cc/layers/surface_layer.h
diff --git a/cc/layers/surface_layer.h b/cc/layers/surface_layer.h
index cf150ab480e6b05a6ee7ad85fede52bd933ecb88..56b1353c2a0fbb1619aa4151e65b71fab078a676 100644
--- a/cc/layers/surface_layer.h
+++ b/cc/layers/surface_layer.h
@@ -22,11 +22,11 @@ class CC_EXPORT SurfaceLayer : public Layer {
   // Layer overrides.
   virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl)
       OVERRIDE;
-  virtual bool DrawsContent() const OVERRIDE;
   virtual void PushPropertiesTo(LayerImpl* layer) OVERRIDE;
 
  protected:
   SurfaceLayer();
+  virtual void UpdateDrawsContent(bool draws_content) OVERRIDE;
 
  private:
   virtual ~SurfaceLayer();