Replace more ObserverList with base::ObserverList.

components/history/core/browser/history_service.h

 // Copyright (c) 2012 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_HISTORY_CORE_BROWSER_HISTORY_SERVICE_H_
 #define COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_SERVICE_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 779 matching lines @@
   scoped_ptr<VisitDelegate> visit_delegate_;
 
   // The history client, may be null when testing. The object should otherwise
   // outlive |HistoryService|.
   HistoryClient* history_client_;
 
   // Has the backend finished loading? The backend is loaded once Init has
   // completed.
   bool backend_loaded_;
 
-  ObserverList<HistoryServiceObserver> observers_;
+  base::ObserverList<HistoryServiceObserver> observers_;
   base::CallbackList<void(const std::set<GURL>&)>
       favicon_changed_callback_list_;
 
   DeleteDirectiveHandler delete_directive_handler_;
 
   // All vended weak pointers are invalidated in Cleanup().
   base::WeakPtrFactory<HistoryService> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryService);
 };
 
 }  // namespace history
 
 #endif  // COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_SERVICE_H_