cc: Add threaded GPU rasterization.

cc/trees/layer_tree_host_impl.h

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_TREES_LAYER_TREE_HOST_IMPL_H_
 #define CC_TREES_LAYER_TREE_HOST_IMPL_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 299 matching lines @@
   void set_gpu_rasterization_status(
       GpuRasterizationStatus gpu_rasterization_status) {
     gpu_rasterization_status_ = gpu_rasterization_status;
   }
 
   bool create_low_res_tiling() const {
     return settings_.create_low_res_tiling && !use_gpu_rasterization_;
   }
   ResourcePool* resource_pool() { return resource_pool_.get(); }
   Renderer* renderer() { return renderer_.get(); }
+  Rasterizer* rasterizer() { return rasterizer_.get(); }
   const RendererCapabilitiesImpl& GetRendererCapabilities() const;
 
   virtual bool SwapBuffers(const FrameData& frame);
   virtual void WillBeginImplFrame(const BeginFrameArgs& args);
   void DidModifyTilePriorities();
 
   LayerTreeImpl* active_tree() { return active_tree_.get(); }
   const LayerTreeImpl* active_tree() const { return active_tree_.get(); }
   LayerTreeImpl* pending_tree() { return pending_tree_.get(); }
   const LayerTreeImpl* pending_tree() const { return pending_tree_.get(); }
@@ skipping 412 matching lines @@
   bool is_likely_to_require_a_draw_;
 
   scoped_ptr<FrameTimingTracker> frame_timing_tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_IMPL_H_