Replace more ObserverList with base::ObserverList.

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/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "base/synchronization/lock.h"
@@ skipping 33 matching lines @@
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
  private:
   friend class base::RefCounted<CompositorVSyncManager>;
 
   ~CompositorVSyncManager();
 
   void NotifyObservers(base::TimeTicks timebase, base::TimeDelta interval);
 
-  ObserverList<Observer> observer_list_;
+  base::ObserverList<Observer> 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_