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

chrome/browser/chromeos/login/screens/mock_enable_debugging_screen.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 CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_MOCK_ENABLE_DEBUGGING_SCREEN_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_MOCK_ENABLE_DEBUGGING_SCREEN_H_
 
 #include "chrome/browser/chromeos/login/screens/enable_debugging_screen.h"
 #include "chrome/browser/chromeos/login/screens/enable_debugging_screen_actor.h"
 #include "google_apis/gaia/google_service_auth_error.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 namespace chromeos {
 
 class MockEnableDebuggingScreen : public EnableDebuggingScreen {
  public:
   MockEnableDebuggingScreen(BaseScreenDelegate* base_screen_delegate,
                             EnableDebuggingScreenActor* actor);
   ~MockEnableDebuggingScreen() override;
 };
 
 class MockEnableDebuggingScreenActor
     : public EnableDebuggingScreenActor {
  public:
   MockEnableDebuggingScreenActor();
-  virtual ~MockEnableDebuggingScreenActor();
+  ~MockEnableDebuggingScreenActor() override;
 
   MOCK_METHOD0(PrepareToShow, void());
   MOCK_METHOD0(Show, void());
   MOCK_METHOD0(Hide, void());
   MOCK_METHOD1(MockSetDelegate, void(Delegate* delegate));
 
-  virtual void SetDelegate(
-      EnableDebuggingScreenActor::Delegate* delegate) override;
+  void SetDelegate(EnableDebuggingScreenActor::Delegate* delegate) override;
 
  private:
   Delegate* delegate_;
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_MOCK_ENABLE_DEBUGGING_SCREEN_H_