Replace more ObserverList with base::ObserverList.

ui/chromeos/ime/input_method_menu_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.
 
 #include "base/observer_list.h"
 #include "ui/chromeos/ime/input_method_menu_item.h"
 #include "ui/chromeos/ui_chromeos_export.h"
 
 #ifndef UI_CHROMEOS_IME_INPUT_METHOD_MENU_MANAGER_H_
 #define UI_CHROMEOS_IME_INPUT_METHOD_MENU_MANAGER_H_
@@ skipping 35 matching lines @@
  private:
   InputMethodMenuManager();
 
   // For Singleton to be able to construct an instance.
   friend struct DefaultSingletonTraits<InputMethodMenuManager>;
 
   // Menu item list of the input method.  This is set by extension IMEs.
   InputMethodMenuItemList menu_list_;
 
   // Observers who will be notified when menu changes.
-  ObserverList<Observer> observers_;
+  base::ObserverList<Observer> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(InputMethodMenuManager);
 };
 
 }  // namespace ime
 }  // namespace ui
 
 #endif // UI_CHROMEOS_IME_INPUT_METHOD_MENU_MANAGER_H_