cc: Block commit on activate by setting a flag on LayerTreeHost.

cc/layers/delegated_renderer_layer.h

Index: cc/layers/delegated_renderer_layer.h
diff --git a/cc/layers/delegated_renderer_layer.h b/cc/layers/delegated_renderer_layer.h
index f16217bb17553650ca0c210d30586ac8ebb10ba9..afee475fedab348a3b14e59f852c145d9bccad28 100644
--- a/cc/layers/delegated_renderer_layer.h
+++ b/cc/layers/delegated_renderer_layer.h
@@ -21,6 +21,7 @@ class CC_EXPORT DelegatedRendererLayer : public Layer {
 
   virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl)
       OVERRIDE;
+  virtual void SetLayerTreeHost(LayerTreeHost* host) OVERRIDE;
   virtual void PushPropertiesTo(LayerImpl* impl) OVERRIDE;
   virtual bool DrawsContent() const OVERRIDE;
 
@@ -36,8 +37,6 @@ class CC_EXPORT DelegatedRendererLayer : public Layer {
   // compositor to the given array, so they can be given back to the child.
   void TakeUnusedResourcesForChildCompositor(ReturnedResourceArray* array);
 
-  virtual bool BlocksPendingCommit() const OVERRIDE;
-
  protected:
   explicit DelegatedRendererLayer(DelegatedRendererLayerClient* client);
   virtual ~DelegatedRendererLayer();