Pass task runners to AudioManager constructor.

media/audio/audio_thread.h

Index: media/audio/audio_thread.h
diff --git a/media/audio/audio_thread.h b/media/audio/audio_thread.h
new file mode 100644
index 0000000000000000000000000000000000000000..7e83d91b5d92893858385ac5085ac210843af0e3
--- /dev/null
+++ b/media/audio/audio_thread.h
@@ -0,0 +1,25 @@
+// Copyright 2016 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_THREAD_H_
+#define MEDIA_AUDIO_AUDIO_THREAD_H_
+
+#include "base/macros.h"
+#include "base/threading/thread.h"
+
+namespace media {
+
+class AudioThread {
+ public:
+  AudioThread();
+  static base::Thread* Get();
+
+ private:
+  base::Thread thread_;
+  DISALLOW_COPY_AND_ASSIGN(AudioThread);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_AUDIO_AUDIO_THREAD_H_