Replace more ObserverList with base::ObserverList.

components/undo/undo_manager.h

 // Copyright 2013 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 COMPONENTS_UNDO_UNDO_MANAGER_H_
 #define COMPONENTS_UNDO_UNDO_MANAGER_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
@@ skipping 91 matching lines @@
 
   // Returns the undo or redo UndoGroup container that should store the next
   // change taking into account if an undo or redo is being executed.
   ScopedVector<UndoGroup>* GetActiveUndoGroup();
 
   // Containers of user actions ready for an undo or redo treated as a stack.
   ScopedVector<UndoGroup> undo_actions_;
   ScopedVector<UndoGroup> redo_actions_;
 
   // The observers to notify when internal state changes.
-  ObserverList<UndoManagerObserver> observers_;
+  base::ObserverList<UndoManagerObserver> observers_;
 
   // Supports grouping operations into a single undo action.
   int group_actions_count_;
 
   // The container that is used when actions are grouped.
   scoped_ptr<UndoGroup> pending_grouped_action_;
 
   // The action that is in the process of being undone.
   UndoGroup* undo_in_progress_action_;
 
   // Supports the suspension of undo tracking.
   int undo_suspended_count_;
 
   // Set when executing Undo or Redo so that incoming changes are correctly
   // processed.
   bool performing_undo_;
   bool performing_redo_;
 
   DISALLOW_COPY_AND_ASSIGN(UndoManager);
 };
 
 #endif  // COMPONENTS_UNDO_UNDO_MANAGER_H_