WIP - compositor worker mega patch.

cc/trees/layer_tree_host.h

Index: cc/trees/layer_tree_host.h
diff --git a/cc/trees/layer_tree_host.h b/cc/trees/layer_tree_host.h
index d8eba8d10738f8c715dc9e3dc8ab1e973f4779b4..d0a695348e95f6e453c2429f4f730ffe2261f3cf 100644
--- a/cc/trees/layer_tree_host.h
+++ b/cc/trees/layer_tree_host.h
@@ -61,6 +61,7 @@ class Layer;
 class LayerTreeHostImpl;
 class LayerTreeHostImplClient;
 class LayerTreeHostSingleThreadClient;
+class LayerTreeMutator;
 class PropertyTrees;
 class Region;
 class RenderingStatsInstrumentation;
@@ -248,6 +249,7 @@ class CC_EXPORT LayerTreeHost : public MutatorHostClient {
                                base::TimeDelta duration);
 
   void ApplyScrollAndScale(ScrollAndScaleSet* info);
+  void ApplyMutations(LayerTreeMutations* mutations);
   void SetImplTransform(const gfx::Transform& transform);
 
   void SetDeviceScaleFactor(float device_scale_factor);
@@ -329,6 +331,8 @@ class CC_EXPORT LayerTreeHost : public MutatorHostClient {
       scoped_ptr<FrameTimingTracker::CompositeTimingSet> composite_events,
       scoped_ptr<FrameTimingTracker::MainFrameTimingSet> main_frame_events);
 
+  void SetLayerTreeMutator(LayerTreeMutator* mutator);
+
   Layer* LayerById(int id) const;
   void RegisterLayer(Layer* layer);
   void UnregisterLayer(Layer* layer);