Revert of Pass task runners to AudioManager constructor.

media/audio/alsa/audio_manager_alsa.h

 // Copyright 2013 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_ALSA_AUDIO_MANAGER_ALSA_H_
 #define MEDIA_AUDIO_ALSA_AUDIO_MANAGER_ALSA_H_
 
 #include <string>
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/threading/thread.h"
 #include "media/audio/audio_manager_base.h"
 
 namespace media {
 
 class AlsaWrapper;
 
 class MEDIA_EXPORT AudioManagerAlsa : public AudioManagerBase {
  public:
-  AudioManagerAlsa(
-      scoped_refptr<base::SingleThreadTaskRunner> task_runner,
-      scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner,
-      AudioLogFactory* audio_log_factory);
+  AudioManagerAlsa(AudioLogFactory* audio_log_factory);
 
   static void ShowLinuxAudioInputSettings();
 
   // Implementation of AudioManager.
   bool HasAudioOutputDevices() override;
   bool HasAudioInputDevices() override;
   void ShowAudioInputSettings() override;
   void GetAudioInputDeviceNames(AudioDeviceNames* device_names) override;
   void GetAudioOutputDeviceNames(AudioDeviceNames* device_names) override;
   AudioParameters GetInputStreamParameters(
@@ skipping 53 matching lines @@
                                     const std::string& device_id);
 
   scoped_ptr<AlsaWrapper> wrapper_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioManagerAlsa);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_ALSA_AUDIO_MANAGER_ALSA_H_