cc: Poll for state that triggers draws (synchronous compositor only)

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 103 matching lines @@
   bool BeginFrameNeededToDrawByImplThread() const;
   bool ProactiveBeginFrameWantedByImplThread() const;
 
   // Indicates that the system has entered and left a BeginFrame callback.
   // The scheduler will not draw more than once in a given BeginFrame
   // callback nor send more than one BeginFrame message.
   void DidEnterBeginFrame(const BeginFrameArgs& args);
   void DidLeaveBeginFrame();
   bool inside_begin_frame() const { return inside_begin_frame_; }
 
+  // PollForAnticipatedDrawTriggers is used by the synchronous compositor to
+  // avoid requesting BeginImplFrames when we won't actually draw but still
+  // need to advance our state at vsync intervals.
+  void PollForAnticipatedDrawTriggers();
+
   // Indicates whether the LayerTreeHostImpl is visible.
   void SetVisible(bool 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();
 
   // Indicates whether a redraw is required because we are currently rendering
   // with a low resolution or checkerboarded tile.
   void SetSwapUsedIncompleteTile(bool used_incomplete_tile);
@@ skipping 102 matching lines @@
   bool draw_if_possible_failed_;
   bool did_create_and_initialize_first_output_surface_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SchedulerStateMachine);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_