Replace more ObserverList with base::ObserverList.

content/browser/download/download_manager_impl.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 CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_MANAGER_IMPL_H_
 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_MANAGER_IMPL_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 159 matching lines @@
   // this session, downloads initialized from the history system, and
   // "save page as" downloads.
   DownloadMap downloads_;
 
   int history_size_;
 
   // True if the download manager has been initialized and requires a shutdown.
   bool shutdown_needed_;
 
   // Observers that want to be notified of changes to the set of downloads.
-  ObserverList<Observer> observers_;
+  base::ObserverList<Observer> observers_;
 
   // The current active browser context.
   BrowserContext* browser_context_;
 
   // Allows an embedder to control behavior. Guaranteed to outlive this object.
   DownloadManagerDelegate* delegate_;
 
   net::NetLog* net_log_;
 
   base::WeakPtrFactory<DownloadManagerImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadManagerImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_MANAGER_IMPL_H_