Decouple BrowserCompositorOutputSurface from BeginFrameSource.

ui/compositor/compositor_vsync_manager.h

 // Copyright 2014 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 UI_COMPOSITOR_COMPOSITOR_VSYNC_MANAGER_H_
 #define UI_COMPOSITOR_COMPOSITOR_VSYNC_MANAGER_H_
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "base/synchronization/lock.h"
 #include "base/time/time.h"
+#include "cc/scheduler/vsync_observer.h"
 #include "ui/compositor/compositor_export.h"
 
 namespace ui {
 
 // This class manages vsync parameters for a compositor. It merges updates of
 // the parameters from different sources and sends the merged updates to
 // observers which register to it.
 class COMPOSITOR_EXPORT CompositorVSyncManager
     : public base::RefCounted<CompositorVSyncManager> {
  public:
-  class Observer {
-   public:
-    virtual void OnUpdateVSyncParameters(base::TimeTicks timebase,
-                                         base::TimeDelta interval) = 0;
-  };
-
   CompositorVSyncManager();
 
   // The "authoritative" vsync interval, if provided, will override |interval|
   // as reported by UpdateVSyncParameters() whenever it is called.  This is
   // typically the value reported by a more reliable source, e.g. the platform
   // display configuration.  In the particular case of ChromeOS -- this is the
   // value queried through XRandR, which is more reliable than the value
   // queried through the 3D context.
   void SetAuthoritativeVSyncInterval(base::TimeDelta interval);
 
   // The vsync parameters consist of |timebase|, which is the platform timestamp
   // of the last vsync, and |interval|, which is the interval between vsyncs.
   // |interval| may be overriden by SetAuthoritativeVSyncInterval() above.
   void UpdateVSyncParameters(base::TimeTicks timebase,
                              base::TimeDelta interval);
 
-  void AddObserver(Observer* observer);
-  void RemoveObserver(Observer* observer);
+  void AddObserver(cc::VSyncObserver* observer);
+  void RemoveObserver(cc::VSyncObserver* observer);
 
  private:
   friend class base::RefCounted<CompositorVSyncManager>;
 
   ~CompositorVSyncManager();
 
   void NotifyObservers(base::TimeTicks timebase, base::TimeDelta interval);
 
-  base::ObserverList<Observer> observer_list_;
+  base::ObserverList<cc::VSyncObserver> observer_list_;
 
   base::TimeTicks last_timebase_;
   base::TimeDelta last_interval_;
   base::TimeDelta authoritative_vsync_interval_;
 
   DISALLOW_COPY_AND_ASSIGN(CompositorVSyncManager);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_COMPOSITOR_VSYNC_MANAGER_H_