replace newly added OVERRIDEs with override in chrome/browser/history/

chrome/browser/history/history_service.cc

 // 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.
 
 // The history system runs on a background thread so that potentially slow
 // database operations don't delay the browser. This backend processing is
 // represented by HistoryBackend. The HistoryService's job is to dispatch to
 // that thread.
 //
 // Main thread                       History thread
@@ skipping 158 matching lines @@
     // Send the notification to the history service on the main thread.
     service_task_runner_->PostTask(
         FROM_HERE,
         base::Bind(
             &HistoryService::NotifyFaviconChanged, history_service_, urls));
   }
 
   virtual void NotifyURLVisited(ui::PageTransition transition,
                                 const history::URLRow& row,
                                 const history::RedirectList& redirects,
-                                base::Time visit_time) OVERRIDE {
+                                base::Time visit_time) override {
     service_task_runner_->PostTask(FROM_HERE,
                                    base::Bind(&HistoryService::NotifyURLVisited,
                                               history_service_,
                                               transition,
                                               row,
                                               redirects,
                                               visit_time));
   }
 
   virtual void BroadcastNotifications(
@@ skipping 1074 matching lines @@
     const HistoryService::OnFaviconChangedCallback& callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
   return favicon_changed_callback_list_.Add(callback);
 }
 
 void HistoryService::NotifyFaviconChanged(
     const std::set<GURL>& changed_favicons) {
   DCHECK(thread_checker_.CalledOnValidThread());
   favicon_changed_callback_list_.Notify(changed_favicons);
 }