Update {virtual,override,final} to follow C++11 style in ash.

ash/system/chromeos/bluetooth/bluetooth_notification_controller.cc

 // Copyright 2014 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.
 
 #include "ash/system/chromeos/bluetooth/bluetooth_notification_controller.h"
 
 #include "ash/system/system_notifier.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/logging.h"
@@ skipping 37 matching lines @@
 // The BluetoothPairingNotificationDelegate handles user interaction with the
 // pairing notification and sending the confirmation, rejection or cancellation
 // back to the underlying device.
 class BluetoothPairingNotificationDelegate
     : public message_center::NotificationDelegate {
  public:
   BluetoothPairingNotificationDelegate(scoped_refptr<BluetoothAdapter> adapter,
                                        const std::string& address);
 
  protected:
-  virtual ~BluetoothPairingNotificationDelegate();
+  ~BluetoothPairingNotificationDelegate() override;
 
   // message_center::NotificationDelegate overrides.
   void Close(bool by_user) override;
   void ButtonClick(int button_index) override;
 
  private:
   // Buttons that appear in notifications.
   enum Button {
     BUTTON_ACCEPT,
     BUTTON_REJECT
@@ skipping 275 matching lines @@
       base::string16() /* display source */,
       message_center::NotifierId(
           message_center::NotifierId::SYSTEM_COMPONENT,
           system_notifier::kNotifierBluetooth),
       optional,
       NULL));
   message_center::MessageCenter::Get()->AddNotification(notification.Pass());
 }
 
 }  // namespace ash