cc: Emulate BeginFrame in OutputSurfaces that don't support it natively

cc/scheduler/scheduler_settings.h

 // Copyright 2013 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_SCHEDULER_SCHEDULER_SETTINGS_H_
 #define CC_SCHEDULER_SCHEDULER_SETTINGS_H_
 
 #include "cc/base/cc_export.h"
 
 namespace cc {
 
 class CC_EXPORT SchedulerSettings {
  public:
   SchedulerSettings();
   ~SchedulerSettings();
 
   bool impl_side_painting;
   bool timeout_and_draw_when_animation_checkerboards;
+  bool using_synchronous_renderer_compositor;
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_SCHEDULER_SETTINGS_H_