Revert of Pass task runners to AudioManager constructor.

media/audio/audio_manager_factory.h

 // Copyright 2015 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_AUDIO_MANAGER_FACTORY_H_
 #define MEDIA_AUDIO_AUDIO_MANAGER_FACTORY_H_
 
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_ptr.h"
 #include "media/base/media_export.h"
 
-namespace base {
-class SingleThreadTaskRunner;
-}  // namespace base
-
 namespace media {
 
 class AudioManager;
-class AudioManagerDeleter;
 class AudioLogFactory;
 
 // Allows a platform-specific implementation of AudioManager to be provided in
 // place of the default implementation at run-time.
 class MEDIA_EXPORT AudioManagerFactory {
  public:
   virtual ~AudioManagerFactory() {}
 
   // Creates an instance of AudioManager implementation. Caller owns the
   // returned instance. |audio_log_factory| must outlive the returned instance.
-  virtual scoped_ptr<AudioManager, AudioManagerDeleter> CreateInstance(
-      scoped_refptr<base::SingleThreadTaskRunner> task_runner,
-      scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner,
-      AudioLogFactory* audio_log_factory) = 0;
+  virtual AudioManager* CreateInstance(AudioLogFactory* audio_log_factory) = 0;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_MANAGER_FACTORY_H_