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

ash/system/chromeos/network/tray_sms.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 ASH_SYSTEM_CHROMEOS_NETWORK_TRAY_SMS_H
 #define ASH_SYSTEM_CHROMEOS_NETWORK_TRAY_SMS_H
 
 #include <string>
 
 #include "ash/system/tray/system_tray_item.h"
 #include "base/values.h"
 #include "chromeos/network/network_sms_handler.h"
 
 namespace ash {
 
 class TraySms : public SystemTrayItem,
                 public chromeos::NetworkSmsHandler::Observer {
  public:
   explicit TraySms(SystemTray* system_tray);
-  virtual ~TraySms();
+  ~TraySms() override;
 
   // Overridden from SystemTrayItem.
-  virtual views::View* CreateDefaultView(user::LoginStatus status) override;
-  virtual views::View* CreateDetailedView(user::LoginStatus status) override;
-  virtual views::View* CreateNotificationView(
-      user::LoginStatus status) override;
-  virtual void DestroyDefaultView() override;
-  virtual void DestroyDetailedView() override;
-  virtual void DestroyNotificationView() override;
+  views::View* CreateDefaultView(user::LoginStatus status) override;
+  views::View* CreateDetailedView(user::LoginStatus status) override;
+  views::View* CreateNotificationView(user::LoginStatus status) override;
+  void DestroyDefaultView() override;
+  void DestroyDetailedView() override;
+  void DestroyNotificationView() override;
 
   // Overridden from chromeos::NetworkSmsHandler::Observer.
-  virtual void MessageReceived(const base::DictionaryValue& message) override;
+  void MessageReceived(const base::DictionaryValue& message) override;
 
  protected:
   class SmsDefaultView;
   class SmsDetailedView;
   class SmsMessageView;
   class SmsNotificationView;
 
   // Gets the most recent message. Returns false if no messages or unable to
   // retrieve the numebr and text from the message.
   bool GetLatestMessage(size_t* index, std::string* number, std::string* text);
@@ skipping 12 matching lines @@
   SmsDetailedView* detailed_;
   SmsNotificationView* notification_;
   base::ListValue messages_;
 
   DISALLOW_COPY_AND_ASSIGN(TraySms);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_CHROMEOS_NETWORK_TRAY_SMS_H