cc: Throttle swaps in Scheduler instead of OutputSurface

cc/scheduler/frame_rate_controller.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_FRAME_RATE_CONTROLLER_H_
 #define CC_SCHEDULER_FRAME_RATE_CONTROLLER_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
 #include "cc/base/cc_export.h"
 #include "cc/output/begin_frame_args.h"
+#include "cc/scheduler/time_source.h"
 
 namespace base { class SingleThreadTaskRunner; }
 
 namespace cc {
 
 class TimeSource;
-class FrameRateController;
+class BeginFrameSource;
 
-class CC_EXPORT FrameRateControllerClient {
+class CC_EXPORT BeginFrameSourceClient {
  protected:
-  virtual ~FrameRateControllerClient() {}
+  virtual ~BeginFrameSourceClient() {}
 
  public:
-  // Throttled is true when we have a maximum number of frames pending.
-  virtual void FrameRateControllerTick(bool throttled,
-                                       const BeginFrameArgs& args) = 0;
+  virtual void BeginImplFrame(const BeginFrameArgs& args) = 0;
 };
 
-class FrameRateControllerTimeSourceAdapter;
+// The BeginFrameSource is used in cases where we self-tick (i.e. BeginFrame
+// is not sent by a parent compositor.
+class CC_EXPORT BeginFrameSource : TimeSourceClient {

[Sami, 2014/03/14 15:34:58]

I wonder if we should call this something like SyntheticBeginFrameSource to make
its purpose a little clearer? Up to you.

+ public:
+  explicit BeginFrameSource(base::TimeDelta interval,
+                            base::SingleThreadTaskRunner* task_runner);
+  virtual ~BeginFrameSource();
 
-// The FrameRateController is used in cases where we self-tick (i.e. BeginFrame
-// is not sent by a parent compositor.
-class CC_EXPORT FrameRateController {
- public:
-  explicit FrameRateController(scoped_refptr<TimeSource> timer);
-  // Alternate form of FrameRateController with unthrottled frame-rate.
-  explicit FrameRateController(base::SingleThreadTaskRunner* task_runner);
-  virtual ~FrameRateController();
-
-  void SetClient(FrameRateControllerClient* client) { client_ = client; }
+  void SetClient(BeginFrameSourceClient* client) { client_ = client; }
 
   // Returns a valid BeginFrame on activation to potentially be used
   // retroactively.
   BeginFrameArgs SetActive(bool active);
 
   bool IsActive() { return active_; }
 
-  // Use the following methods to adjust target frame rate.
-  //
-  // Multiple frames can be in-progress, but for every DidSwapBuffers, a
-  // DidFinishFrame should be posted.
-  //
-  // If the rendering pipeline crashes, call DidAbortAllPendingFrames.
-  void DidSwapBuffers();
-  void DidSwapBuffersComplete();
-  void DidAbortAllPendingFrames();
-  void SetMaxSwapsPending(int max_swaps_pending);  // 0 for unlimited.
-  int MaxSwapsPending() const { return max_swaps_pending_; }
-  int NumSwapsPendingForTesting() const { return num_frames_pending_; }
-
   void SetTimebaseAndInterval(base::TimeTicks timebase,
                               base::TimeDelta interval);
   void SetDeadlineAdjustment(base::TimeDelta delta);
 
+  virtual void OnTimerTick() OVERRIDE;
+
  protected:
-  friend class FrameRateControllerTimeSourceAdapter;
-  void OnTimerTick();
-
-  void PostManualTick();
-  void ManualTick();
-
     // This returns null for unthrottled frame-rate.
   base::TimeTicks NextTickTime();
   // This returns now for unthrottled frame-rate.
   base::TimeTicks LastTickTime();
 
-  FrameRateControllerClient* client_;
-  int num_frames_pending_;
-  int max_swaps_pending_;
+  BeginFrameSourceClient* client_;
   base::TimeDelta interval_;
   base::TimeDelta deadline_adjustment_;
   scoped_refptr<TimeSource> time_source_;
-  scoped_ptr<FrameRateControllerTimeSourceAdapter> time_source_client_adapter_;
   bool active_;
 
-  // Members for unthrottled frame-rate.
-  bool is_time_source_throttling_;
-  bool manual_tick_pending_;
-  base::SingleThreadTaskRunner* task_runner_;
-  base::WeakPtrFactory<FrameRateController> weak_factory_;
-
  private:
-  DISALLOW_COPY_AND_ASSIGN(FrameRateController);
+  DISALLOW_COPY_AND_ASSIGN(BeginFrameSource);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_FRAME_RATE_CONTROLLER_H_