Making OutputSurface a begin frame source and vsync source.

cc/scheduler/scheduler_state_machine.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_SCHEDULER_SCHEDULER_STATE_MACHINE_H_
 #define CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 131 matching lines @@
   // avoid requesting BeginImplFrames when we won't actually draw but still
   // need to advance our state at vsync intervals.
   void DidEnterPollForAnticipatedDrawTriggers();
   void DidLeavePollForAnticipatedDrawTriggers();
   bool inside_poll_for_anticipated_draw_triggers() const {
     return inside_poll_for_anticipated_draw_triggers_;
   }
 
   // Indicates whether the LayerTreeHostImpl is visible.
   void SetVisible(bool visible);
+  bool visible() const { return visible_; }
 
   // Indicates that a redraw is required, either due to the impl tree changing
   // or the screen being damaged and simply needing redisplay.
   void SetNeedsRedraw();
   bool needs_redraw() const { return needs_redraw_; }
 
   void SetNeedsAnimate();
   bool needs_animate() const { return needs_animate_; }
 
   // Indicates that manage-tiles is required. This guarantees another
@@ skipping 152 matching lines @@
   bool skip_begin_main_frame_to_reduce_latency_;
   bool continuous_painting_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SchedulerStateMachine);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_