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

base/message_loop/message_pump_android.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 BASE_MESSAGE_LOOP_MESSAGE_PUMP_ANDROID_H_
 #define BASE_MESSAGE_LOOP_MESSAGE_PUMP_ANDROID_H_
 
 #include <jni.h>
 
 #include "base/android/scoped_java_ref.h"
 #include "base/base_export.h"
 #include "base/compiler_specific.h"
 #include "base/message_loop/message_pump.h"
 
 namespace base {
 
 class RunLoop;
 class TimeTicks;
 
 // This class implements a MessagePump needed for TYPE_UI MessageLoops on
 // OS_ANDROID platform.
 class BASE_EXPORT MessagePumpForUI : public MessagePump {
  public:
   MessagePumpForUI();
-  virtual ~MessagePumpForUI();
+  ~MessagePumpForUI() override;
 
-  virtual void Run(Delegate* delegate) override;
-  virtual void Quit() override;
-  virtual void ScheduleWork() override;
-  virtual void ScheduleDelayedWork(const TimeTicks& delayed_work_time) override;
+  void Run(Delegate* delegate) override;
+  void Quit() override;
+  void ScheduleWork() override;
+  void ScheduleDelayedWork(const TimeTicks& delayed_work_time) override;
 
   virtual void Start(Delegate* delegate);
 
   static bool RegisterBindings(JNIEnv* env);
 
  private:
   RunLoop* run_loop_;
   base::android::ScopedJavaGlobalRef<jobject> system_message_handler_obj_;
 
   DISALLOW_COPY_AND_ASSIGN(MessagePumpForUI);
 };
 
 }  // namespace base
 
 #endif  // BASE_MESSAGE_LOOP_MESSAGE_PUMP_ANDROID_H_