Redesign the copresence audio handlers.

components/copresence/mediums/audio/audio_player_stub.h

+// Copyright 2014 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 COMPONENTS_COPRESENCE_MEDIUMS_AUDIO_AUDIO_PLAYER_STUB_H_
+#define COMPONENTS_COPRESENCE_MEDIUMS_AUDIO_AUDIO_PLAYER_STUB_H_
+
+#include "base/macros.h"
+#include "components/copresence/mediums/audio/audio_player.h"
+
+namespace media {
+class AudioBusRefCounted;
+}
+
+namespace copresence {
+
+class AudioPlayerStub final : public AudioPlayer {
+ public:
+  AudioPlayerStub();
+  virtual ~AudioPlayerStub();
+
+  // AudioPlayer overrides:
+  virtual void Initialize() override;
+  virtual void Play(
+      const scoped_refptr<media::AudioBusRefCounted>& samples) override;
+  virtual void Stop() override;
+  virtual void Finalize() override;
+  virtual bool IsPlaying() override;
+
+ private:
+  bool is_playing_;
+  DISALLOW_COPY_AND_ASSIGN(AudioPlayerStub);
+};
+
+}  // namespace copresence
+
+#endif  // COMPONENTS_COPRESENCE_MEDIUMS_AUDIO_AUDIO_PLAYER_STUB_H_