Revert of Pass task runners to AudioManager constructor.

chromecast/media/audio/cast_audio_manager_factory.cc

 // 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.
 
 #include "chromecast/media/audio/cast_audio_manager_factory.h"
 
 #include "chromecast/media/audio/cast_audio_manager.h"
 #include "chromecast/media/cma/backend/media_pipeline_backend_manager.h"
 
 namespace chromecast {
 namespace media {
 
 CastAudioManagerFactory::CastAudioManagerFactory(
     MediaPipelineBackendManager* backend_manager)
     : backend_manager_(backend_manager) {
 }
 
 CastAudioManagerFactory::~CastAudioManagerFactory() {}
 
-scoped_ptr<::media::AudioManager, ::media::AudioManagerDeleter>
-CastAudioManagerFactory::CreateInstance(
-    scoped_refptr<base::SingleThreadTaskRunner> task_runner,
-    scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner,
+::media::AudioManager* CastAudioManagerFactory::CreateInstance(
     ::media::AudioLogFactory* audio_log_factory) {
-  return scoped_ptr<::media::AudioManager, ::media::AudioManagerDeleter>(
-      new CastAudioManager(std::move(task_runner),
-                           std::move(worker_task_runner), audio_log_factory,
-                           backend_manager_));
+  return new CastAudioManager(audio_log_factory, backend_manager_);
 }
 
 }  // namespace media
 }  // namespace chromecast