Standardize usage of virtual/override/final in media/

media/audio/scoped_task_runner_observer.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 MEDIA_AUDIO_SCOPED_TASK_RUNNER_OBSERVER_H_
 #define MEDIA_AUDIO_SCOPED_TASK_RUNNER_OBSERVER_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop.h"
 
@@ skipping 10 matching lines @@
 // from the task runner's list of destruction observers.
 // NOTE: The class that inherits from this class must implement the
 // WillDestroyCurrentMessageLoop virtual method from DestructionObserver.
 class ScopedTaskRunnerObserver
     : public base::MessageLoop::DestructionObserver {
  public:
   explicit ScopedTaskRunnerObserver(
       const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
 
  protected:
-  virtual ~ScopedTaskRunnerObserver();
+  ~ScopedTaskRunnerObserver() override;
 
   // Accessor to the loop that's used by the derived class.
   const scoped_refptr<base::SingleThreadTaskRunner>& task_runner() {
     return task_runner_;
   }
 
  private:
   // Call to add or remove ourselves from the list of destruction observers for
   // the message loop.
   void ObserveLoopDestruction(bool enable, base::WaitableEvent* done);
 
   // A pointer to the task runner. In case it gets destroyed before this object
   // goes out of scope, PostTask() etc will fail but not crash.
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedTaskRunnerObserver);
 };
 
 }  // namespace media.
 
 #endif  // MEDIA_AUDIO_SCOPED_TASK_RUNNER_OBSERVER_H_