cc: Add initial GPU-to-GPU copy rasterizer implementation.

cc/trees/layer_tree_host_impl.h

Index: cc/trees/layer_tree_host_impl.h
diff --git a/cc/trees/layer_tree_host_impl.h b/cc/trees/layer_tree_host_impl.h
index aa02278444fcbc15f5afd72a148e5335b67782e1..4e7c0ca12a243617c037eee95f6ffa2edde8f9d0 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -470,7 +470,8 @@ class CC_EXPORT LayerTreeHostImpl
       bool skip_gl_renderer);
   void CreateAndSetTileManager(ResourceProvider* resource_provider,
                                ContextProvider* context_provider,
-                               bool using_map_image,
+                               bool use_zero_copy,
+                               bool use_one_copy,
                                bool allow_rasterize_on_demand);
   void ReleaseTreeResources();
   void EnforceZeroBudget(bool zero_budget);
@@ -545,6 +546,7 @@ class CC_EXPORT LayerTreeHostImpl
   scoped_ptr<RasterWorkerPool> raster_worker_pool_;
   scoped_ptr<RasterWorkerPool> direct_raster_worker_pool_;
   scoped_ptr<ResourcePool> resource_pool_;
+  scoped_ptr<ResourcePool> staging_resource_pool_;
   scoped_ptr<Renderer> renderer_;
 
   GlobalStateThatImpactsTilePriority global_tile_state_;
@@ -657,6 +659,8 @@ class CC_EXPORT LayerTreeHostImpl
 
   std::set<SwapPromiseMonitor*> swap_promise_monitor_;
 
+  size_t transfer_buffer_memory_limit_;
+
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };