cc:: Change plumbing for external_begin_frame_source to the Scheduler.

cc/trees/layer_tree_host.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_H_
 #define CC_TREES_LAYER_TREE_HOST_H_
 
 #include <limits>
 #include <set>
 #include <string>
@@ skipping 351 matching lines @@
  protected:
   LayerTreeHost(InitParams* params, CompositorMode mode);
   void InitializeThreaded(
       scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
       scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner,
       scoped_ptr<BeginFrameSource> external_begin_frame_source);
   void InitializeSingleThreaded(
       LayerTreeHostSingleThreadClient* single_thread_client,
       scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
       scoped_ptr<BeginFrameSource> external_begin_frame_source);
-  void InitializeForTesting(scoped_ptr<TaskRunnerProvider> task_runner_provider,
-                            scoped_ptr<Proxy> proxy_for_testing);
+  void InitializeForTesting(
+      scoped_ptr<TaskRunnerProvider> task_runner_provider,
+      scoped_ptr<Proxy> proxy_for_testing,
+      scoped_ptr<BeginFrameSource> external_begin_frame_source);
   void SetOutputSurfaceLostForTesting(bool is_lost) {
     output_surface_lost_ = is_lost;
   }
 
   // shared_bitmap_manager(), gpu_memory_buffer_manager(), and
   // task_graph_runner() return valid values only until the LayerTreeHostImpl is
   // created in CreateLayerTreeHostImpl().
   SharedBitmapManager* shared_bitmap_manager() const {
     return shared_bitmap_manager_;
   }
   gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager() const {
     return gpu_memory_buffer_manager_;
   }
   TaskGraphRunner* task_graph_runner() const { return task_graph_runner_; }
 
   MicroBenchmarkController micro_benchmark_controller_;
 
   void OnCommitForSwapPromises();
 
  private:
-  void InitializeProxy(scoped_ptr<Proxy> proxy);
+  void InitializeProxy(
+      scoped_ptr<Proxy> proxy,
+      scoped_ptr<BeginFrameSource> external_begin_frame_source);
 
   bool DoUpdateLayers(Layer* root_layer);
   void UpdateHudLayer();
 
   bool AnimateLayersRecursive(Layer* current, base::TimeTicks time);
 
   bool IsSingleThreaded() const;
   bool IsThreaded() const;
 
   struct UIResourceClientData {
@@ skipping 101 matching lines @@
 
   uint32_t surface_id_namespace_;
   uint32_t next_surface_sequence_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_H_