cc: Throttle swaps in Scheduler instead of OutputSurface

cc/output/output_surface.h

 // Copyright 2012 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_OUTPUT_OUTPUT_SURFACE_H_
 #define CC_OUTPUT_OUTPUT_SURFACE_H_
 
 #include <deque>
 
 #include "base/basictypes.h"
@@ skipping 86 matching lines @@
   // (namely Android WebView), this is called to determine whether the software
   // device should be used on the current frame.
   virtual bool ForcedDrawToSoftwareDevice() const;
 
   // Called by the compositor on the compositor thread. This is a place where
   // thread-specific data for the output surface can be initialized, since from
   // this point on the output surface will only be used on the compositor
   // thread.
   virtual bool BindToClient(OutputSurfaceClient* client);
 
+  // Enable or disable vsync.
+  void SetThrottleFrameProduction(bool enable);
+
   void InitializeBeginImplFrameEmulation(

[brianderson, 2014/03/13 21:11:52]

In the interest of simplifying OutputSurface, we could probably move all the
BeginImplFrameEmulation logic into a separate class owned by the LTHI.

       base::SingleThreadTaskRunner* task_runner,
-      bool throttle_frame_production,
       base::TimeDelta interval);
 
-  void SetMaxFramesPending(int max_frames_pending);
-
   virtual void EnsureBackbuffer();
   virtual void DiscardBackbuffer();
 
   virtual void Reshape(const gfx::Size& size, float scale_factor);
   virtual gfx::Size SurfaceSize() const;
 
   virtual void BindFramebuffer();
 
   // The implementation may destroy or steal the contents of the CompositorFrame
   // passed in (though it will not take ownership of the CompositorFrame
@@ skipping 25 matching lines @@
       scoped_refptr<ContextProvider> offscreen_context_provider);
   void ReleaseGL();
 
   void PostSwapBuffersComplete();
 
   struct OutputSurface::Capabilities capabilities_;
   scoped_refptr<ContextProvider> context_provider_;
   scoped_ptr<SoftwareOutputDevice> software_device_;
   gfx::Size surface_size_;
   float device_scale_factor_;
+  base::TimeDelta begin_impl_frame_interval_;
 
   // The FrameRateController is deprecated.
   // Platforms should move to native BeginImplFrames instead.
   void CommitVSyncParameters(base::TimeTicks timebase,
                              base::TimeDelta interval);
-  virtual void FrameRateControllerTick(bool throttled,
-                                       const BeginFrameArgs& args) OVERRIDE;
+  virtual void FrameRateControllerTick(const BeginFrameArgs& args) OVERRIDE;
   scoped_ptr<FrameRateController> frame_rate_controller_;
-  int max_frames_pending_;
-  int pending_swap_buffers_;
+  bool throttle_frame_production_;
   bool needs_begin_impl_frame_;
   bool client_ready_for_begin_impl_frame_;
 
   // This stores a BeginImplFrame that we couldn't process immediately,
   // but might process retroactively in the near future.
   BeginFrameArgs skipped_begin_impl_frame_args_;
 
   // Forwarded to OutputSurfaceClient but threaded through OutputSurface
   // first so OutputSurface has a chance to update the FrameRateController
   void SetNeedsRedrawRect(const gfx::Rect& damage_rect);
@@ skipping 14 matching lines @@
   void CheckForRetroactiveBeginImplFrame();
 
  private:
   OutputSurfaceClient* client_;
 
   void SetUpContext3d();
   void ResetContext3d();
   void SetMemoryPolicy(const ManagedMemoryPolicy& policy);
   void UpdateAndMeasureGpuLatency();
 
+  bool is_lost_;
+
   // check_for_retroactive_begin_impl_frame_pending_ is used to avoid posting
   // redundant checks for a retroactive BeginImplFrame.
   bool check_for_retroactive_begin_impl_frame_pending_;
 
   bool external_stencil_test_enabled_;
 
   base::WeakPtrFactory<OutputSurface> weak_ptr_factory_;
 
   std::deque<unsigned> available_gpu_latency_query_ids_;
   std::deque<unsigned> pending_gpu_latency_query_ids_;
   RollingTimeDeltaHistory gpu_latency_history_;
 
   DISALLOW_COPY_AND_ASSIGN(OutputSurface);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_OUTPUT_SURFACE_H_