Replace MessageLoopProxy with SingleThreadTaskRunner for the rest of media/.

media/audio/scoped_loop_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_LOOP_OBSERVER_H_
-#define MEDIA_AUDIO_SCOPED_LOOP_OBSERVER_H_
-
-#include "base/memory/ref_counted.h"
-#include "base/message_loop/message_loop.h"
-#include "base/message_loop/message_loop_proxy.h"
-
-namespace base {
-class WaitableEvent;
-}
-
-namespace media {
-
-// A common base class for AudioOutputDevice and AudioInputDevice that manages
-// a message loop pointer and monitors it for destruction. If the object goes
-// out of scope before the message loop, the object will automatically remove
-// itself from the message loop's list of destruction observers.
-// NOTE: The class that inherits from this class must implement the
-// WillDestroyCurrentMessageLoop virtual method from DestructionObserver.
-class ScopedLoopObserver
-    : public base::MessageLoop::DestructionObserver {
- public:
-  explicit ScopedLoopObserver(
-      const scoped_refptr<base::MessageLoopProxy>& message_loop);
-
- protected:
-  virtual ~ScopedLoopObserver();
-
-  // Accessor to the loop that's used by the derived class.
-  const scoped_refptr<base::MessageLoopProxy>& message_loop() { return loop_; }
-
- 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 message loop's proxy. In case the loop gets destroyed
-  // before this object goes out of scope, PostTask etc will fail but not crash.
-  scoped_refptr<base::MessageLoopProxy> loop_;
-
-  DISALLOW_COPY_AND_ASSIGN(ScopedLoopObserver);
-};
-
-}  // namespace media.
-
-#endif  // MEDIA_AUDIO_SCOPED_LOOP_OBSERVER_H_