Make AudioDebugFileWriter create its own file worker thread.

media/audio/mock_audio_manager.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_MOCK_AUDIO_MANAGER_H_
 #define MEDIA_AUDIO_MOCK_AUDIO_MANAGER_H_
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/sequenced_task_runner_helpers.h"
@@ skipping 29 matching lines @@
       const media::AudioParameters& params,
       const std::string& device_id,
       const LogCallback& log_callback) override;
 
   void AddOutputDeviceChangeListener(AudioDeviceListener* listener) override;
   void RemoveOutputDeviceChangeListener(AudioDeviceListener* listener) override;
 
   std::unique_ptr<AudioLog> CreateAudioLog(
       AudioLogFactory::AudioComponent component) override;
 
-  void InitializeOutputDebugRecording(
-      scoped_refptr<base::SingleThreadTaskRunner> file_task_runner) override;
+  void InitializeOutputDebugRecording() override;
   void EnableOutputDebugRecording(
       const base::FilePath& base_file_name) override;
   void DisableOutputDebugRecording() override;
 
   const char* GetName() override;
 
   // Setters to emulate desired in-test behavior.
   void SetInputStreamParameters(const AudioParameters& params);
   void SetOutputStreamParameters(const AudioParameters& params);
   void SetDefaultOutputStreamParameters(const AudioParameters& params);
@@ skipping 40 matching lines @@
   GetDeviceDescriptionsCallback get_input_device_descriptions_cb_;
   GetDeviceDescriptionsCallback get_output_device_descriptions_cb_;
   GetAssociatedOutputDeviceIDCallback get_associated_output_device_id_cb_;
 
   DISALLOW_COPY_AND_ASSIGN(MockAudioManager);
 };
 
 }  // namespace media.
 
 #endif  // MEDIA_AUDIO_MOCK_AUDIO_MANAGER_H_