Hoist begin frame sources out of scheduler

cc/scheduler/scheduler.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_H_
 #define CC_SCHEDULER_SCHEDULER_H_
 
 #include <deque>
 #include <string>
 
@@ skipping 37 matching lines @@
   virtual void DidFinishImplFrame() = 0;
   virtual void SendBeginFramesToChildren(const BeginFrameArgs& args) = 0;
   virtual void SendBeginMainFrameNotExpectedSoon() = 0;
 
  protected:
   virtual ~SchedulerClient() {}
 };
 
 class CC_EXPORT Scheduler : public BeginFrameObserverBase {
  public:
   static scoped_ptr<Scheduler> Create(

[Sami, 2016/03/08 19:15:24]

Could you add a note saying both |client| and |begin_frame_source| need to
outlive the scheduler?

       SchedulerClient* client,
       const SchedulerSettings& scheduler_settings,
       int layer_tree_host_id,
       base::SingleThreadTaskRunner* task_runner,
-      BeginFrameSource* external_frame_source,
+      BeginFrameSource* begin_frame_source,
       scoped_ptr<CompositorTimingHistory> compositor_timing_history);
 
   ~Scheduler() override;
 
   // BeginFrameObserverBase
   void OnBeginFrameSourcePausedChanged(bool paused) override;
   bool OnBeginFrameDerivedImpl(const BeginFrameArgs& args) override;
 
   void OnDrawForOutputSurface(bool resourceless_software_draw);
 
   const SchedulerSettings& settings() const { return settings_; }
 
-  void CommitVSyncParameters(base::TimeTicks timebase,
-                             base::TimeDelta interval);
   void SetEstimatedParentDrawTime(base::TimeDelta draw_time);
 
   void SetVisible(bool visible);
   bool visible() { return state_machine_.visible(); }
   void SetCanDraw(bool can_draw);
   void NotifyReadyToActivate();
   void NotifyReadyToDraw();
 
   void SetNeedsBeginMainFrame();
   // Requests a single impl frame (after the current frame if there is one
@@ skipping 47 matching lines @@
   base::TimeTicks LastBeginImplFrameTime();
 
   void SetDeferCommits(bool defer_commits);
 
   scoped_ptr<base::trace_event::ConvertableToTraceFormat> AsValue() const;
   void AsValueInto(base::trace_event::TracedValue* value) const override;
 
   void SetChildrenNeedBeginFrames(bool children_need_begin_frames);
   void SetVideoNeedsBeginFrames(bool video_needs_begin_frames);
 
-  void SetAuthoritativeVSyncInterval(const base::TimeDelta& interval);
-
  protected:
   Scheduler(SchedulerClient* client,
             const SchedulerSettings& scheduler_settings,
             int layer_tree_host_id,
             base::SingleThreadTaskRunner* task_runner,
-            BeginFrameSource* external_frame_source,
-            scoped_ptr<SyntheticBeginFrameSource> synthetic_frame_source,
-            scoped_ptr<BackToBackBeginFrameSource> unthrottled_frame_source,
+            BeginFrameSource* begin_frame_source,
             scoped_ptr<CompositorTimingHistory> compositor_timing_history);
 
   // Virtual for testing.
   virtual base::TimeTicks Now() const;
 
   const SchedulerSettings settings_;
   SchedulerClient* client_;
   int layer_tree_host_id_;
   base::SingleThreadTaskRunner* task_runner_;
-  BeginFrameSource* external_frame_source_;
-  scoped_ptr<SyntheticBeginFrameSource> synthetic_frame_source_;
-  scoped_ptr<BackToBackBeginFrameSource> unthrottled_frame_source_;
 
-  scoped_ptr<BeginFrameSourceMultiplexer> frame_source_;
+  BeginFrameSource* frame_source_;

[Sami, 2016/03/08 19:15:25]

nit: Could you add "  // Not owned." to make it clear we don't manage the
source's lifetime?

double-nit: maybe also rename to begin_frame_source_ for consistency?

   bool observing_frame_source_;
 
-  base::TimeDelta authoritative_vsync_interval_;
-  base::TimeTicks last_vsync_timebase_;
-
   scoped_ptr<CompositorTimingHistory> compositor_timing_history_;
   base::TimeDelta estimated_parent_draw_time_;
 
   std::deque<BeginFrameArgs> begin_retro_frame_args_;
   SchedulerStateMachine::BeginImplFrameDeadlineMode
       begin_impl_frame_deadline_mode_;
   BeginFrameTracker begin_impl_frame_tracker_;
   BeginFrameArgs begin_main_frame_args_;
 
   base::Closure begin_retro_frame_closure_;
@@ skipping 33 matching lines @@
   void PollToAdvanceCommitState();
 
   base::TimeDelta EstimatedParentDrawTime() {
     return estimated_parent_draw_time_;
   }
 
   bool IsInsideAction(SchedulerStateMachine::Action action) {
     return inside_action_ == action;
   }
 
-  BeginFrameSource* primary_frame_source() {
-    if (settings_.use_external_begin_frame_source) {
-      DCHECK(external_frame_source_);
-      return external_frame_source_;
-    }
-    return synthetic_frame_source_.get();
-  }
-
   base::WeakPtrFactory<Scheduler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Scheduler);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_SCHEDULER_H_