[wip] hack to use synthetic bfs for browser compositor

cc/trees/single_thread_proxy.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_SINGLE_THREAD_PROXY_H_
 #define CC_TREES_SINGLE_THREAD_PROXY_H_
 
 #include <limits>
 
 #include "base/cancelable_callback.h"
@@ skipping 111 matching lines @@
 
   // Accessed on main thread only.
   LayerTreeHostInProcess* layer_tree_host_;
   LayerTreeHostSingleThreadClient* single_thread_client_;
 
   TaskRunnerProvider* task_runner_provider_;
 
   // Used on the Thread, but checked on main thread during
   // initialization/shutdown.
   std::unique_ptr<LayerTreeHostImpl> layer_tree_host_impl_;
+  std::unique_ptr<SyntheticBeginFrameSource> synthetic_begin_frame_source_;
 
   // Accessed from both threads.
   std::unique_ptr<Scheduler> scheduler_on_impl_thread_;
 
   std::unique_ptr<BlockingTaskRunner::CapturePostTasks>
       commit_blocking_task_runner_;
   bool next_frame_is_newly_committed_frame_;
 
 #if DCHECK_IS_ON()
   bool inside_impl_frame_;
@@ skipping 90 matching lines @@
  private:
   DebugScopedSetImplThread impl_thread_;
   DebugScopedSetMainThreadBlocked main_thread_blocked_;
 
   DISALLOW_COPY_AND_ASSIGN(DebugScopedSetImplThreadAndMainThreadBlocked);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_SINGLE_THREAD_PROXY_H_