replace 'virtual ... OVERRIDE' with '... override'

base/prefs/pref_store_observer_mock.h

 // Copyright (c) 2011 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 BASE_PREFS_PREF_STORE_OBSERVER_MOCK_H_
 #define BASE_PREFS_PREF_STORE_OBSERVER_MOCK_H_
 
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/prefs/pref_store.h"
 
 // A mock implementation of PrefStore::Observer.
 class PrefStoreObserverMock : public PrefStore::Observer {
  public:
   PrefStoreObserverMock();
   virtual ~PrefStoreObserverMock();
 
   void VerifyAndResetChangedKey(const std::string& expected);
 
   // PrefStore::Observer implementation
-  virtual void OnPrefValueChanged(const std::string& key) OVERRIDE;
-  virtual void OnInitializationCompleted(bool success) OVERRIDE;
+  void OnPrefValueChanged(const std::string& key) override;
+  void OnInitializationCompleted(bool success) override;
 
   std::vector<std::string> changed_keys;
   bool initialized;
   bool initialization_success;  // Only valid if |initialized|.
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PrefStoreObserverMock);
 };
 
 #endif  // BASE_PREFS_PREF_STORE_OBSERVER_MOCK_H_