Replace more ObserverList with base::ObserverList.

content/renderer/pepper/plugin_instance_throttler_impl.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 CONTENT_RENDERER_PEPPER_PLUGIN_INSTANCE_THROTTLER_IMPL_H_
 #define CONTENT_RENDERER_PEPPER_PLUGIN_INSTANCE_THROTTLER_IMPL_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
@@ skipping 89 matching lines @@
   int frames_examined_;
 
   // Plugin's unobscured dimensions as of initialization.
   gfx::Size unobscured_size_;
 
   // Video plugins with throttled audio often stop generating frames.
   // This timer is so we don't wait forever for candidate poster frames.
   bool audio_throttled_;
   base::DelayTimer<PluginInstanceThrottlerImpl> audio_throttled_frame_timeout_;
 
-  ObserverList<Observer> observer_list_;
+  base::ObserverList<Observer> observer_list_;
 
   base::WeakPtrFactory<PluginInstanceThrottlerImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginInstanceThrottlerImpl);
 };
 }
 
 #endif  // CONTENT_RENDERER_PEPPER_PLUGIN_INSTANCE_THROTTLER_IMPL_H_