cc: GPU rasterize tiles synchronously in PrepareToDraw.

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 03ddaa050d8288544f7fd87a59f981c484282061..045b44c0418f3fb66acdee142133cbfb485c2780 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -53,6 +53,7 @@ class PaintTimeCounter;
 class PictureLayerImpl;
 class RasterTilePriorityQueue;
 class TileTaskWorkerPool;
+class Rasterizer;
 class RenderPassDrawQuad;
 class RenderingStatsInstrumentation;
 class ResourcePool;
@@ -502,6 +503,7 @@ class CC_EXPORT LayerTreeHostImpl
 
   virtual void CreateResourceAndTileTaskWorkerPool(
       scoped_ptr<TileTaskWorkerPool>* tile_task_worker_pool,
+      scoped_ptr<Rasterizer>* rasterizer,
       scoped_ptr<ResourcePool>* resource_pool,
       scoped_ptr<ResourcePool>* staging_resource_pool);
 
@@ -612,6 +614,7 @@ class CC_EXPORT LayerTreeHostImpl
   bool use_gpu_rasterization_;
   GpuRasterizationStatus gpu_rasterization_status_;
   scoped_ptr<TileTaskWorkerPool> tile_task_worker_pool_;
+  scoped_ptr<Rasterizer> rasterizer_;
   scoped_ptr<ResourcePool> resource_pool_;
   scoped_ptr<ResourcePool> staging_resource_pool_;
   scoped_ptr<Renderer> renderer_;