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

chrome/browser/history/in_memory_history_backend.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.
 
 // The InMemoryHistoryBackend is a wrapper around the in-memory URL database.
 // It maintains an in-memory cache of a subset of history that is required for
 // low-latency operations, such as in-line autocomplete.
 //
 // The in-memory cache provides the following guarantees:
 //  (1.) It will always contain URLRows that either have a |typed_count| > 0; or
@@ skipping 60 matching lines @@
   // so that it can deal directly with this object, rather than the DB.
   InMemoryDatabase* db() const {
     return db_.get();
   }
 
   // HistoryServiceObserver:
   virtual void OnURLVisited(HistoryService* history_service,
                             ui::PageTransition transition,
                             const URLRow& row,
                             const RedirectList& redirects,
-                            base::Time visit_time) OVERRIDE;
+                            base::Time visit_time) override;
 
   // Notification callback.
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) override;
 
  private:
   FRIEND_TEST_ALL_PREFIXES(HistoryBackendTest, DeleteAll);
 
   // Handler for HISTORY_URL_VISITED and HISTORY_URLS_MODIFIED.
@@ skipping 16 matching lines @@
   // initialization.
   Profile* profile_;
   HistoryService* history_service_;
 
   DISALLOW_COPY_AND_ASSIGN(InMemoryHistoryBackend);
 };
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_IN_MEMORY_HISTORY_BACKEND_H_