Redesign the copresence audio handlers.

components/copresence/mediums/audio/audio_player.h

Index: components/copresence/mediums/audio/audio_player.h
diff --git a/components/copresence/mediums/audio/audio_player.h b/components/copresence/mediums/audio/audio_player.h
index 96c1f0f3bf1a267703b07fd221bc59b5e6993e26..742c4bcd0d4e3f18211732b112284052837feb82 100644
--- a/components/copresence/mediums/audio/audio_player.h
+++ b/components/copresence/mediums/audio/audio_player.h
@@ -20,25 +20,42 @@ class AudioBusRefCounted;
 
 namespace copresence {
 
-// The AudioPlayer class will play a set of samples till it is told to stop.
-class AudioPlayer : public media::AudioOutputStream::AudioSourceCallback {
+// The AudioPlayerImpl class will play a set of samples till it is told to stop.
+class AudioPlayer {
  public:
-  AudioPlayer();
-
   // Initializes the object. Do not use this object before calling this method.
-  virtual void Initialize();
+  virtual void Initialize() = 0;
 
   // Play the given samples. These samples will keep on being played in a loop
   // till we explicitly tell the player to stop playing.
-  virtual void Play(const scoped_refptr<media::AudioBusRefCounted>& samples);
+  virtual void Play(
+      const scoped_refptr<media::AudioBusRefCounted>& samples) = 0;
 
   // Stop playing.
-  virtual void Stop();
+  virtual void Stop() = 0;
 
   // Cleans up and deletes this object. Do not use object after this call.
-  virtual void Finalize();
+  virtual void Finalize() = 0;
+
+  virtual bool IsPlaying() = 0;
+
+ protected:
+  virtual ~AudioPlayer() {}
+};
 
-  bool IsPlaying();
+// The AudioPlayerImpl class will play a set of samples till it is told to stop.
+class AudioPlayerImpl : public AudioPlayer,
+                        public media::AudioOutputStream::AudioSourceCallback {
+ public:
+  AudioPlayerImpl();
+
+  // 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;
 
   // Takes ownership of the stream.
   void set_output_stream_for_testing(
@@ -46,15 +63,13 @@ class AudioPlayer : public media::AudioOutputStream::AudioSourceCallback {
     output_stream_for_testing_.reset(output_stream_for_testing);
   }
 
- protected:
-  virtual ~AudioPlayer();
-  void set_is_playing(bool is_playing) { is_playing_ = is_playing; }
-
  private:
   friend class AudioPlayerTest;
   FRIEND_TEST_ALL_PREFIXES(AudioPlayerTest, BasicPlayAndStop);
   FRIEND_TEST_ALL_PREFIXES(AudioPlayerTest, OutOfOrderPlayAndStopMultiple);
 
+  virtual ~AudioPlayerImpl();
+
   // Methods to do our various operations; all of these need to be run on the
   // audio thread.
   void InitializeOnAudioThread();
@@ -89,7 +104,7 @@ class AudioPlayer : public media::AudioOutputStream::AudioSourceCallback {
   // Index to the frame in the samples that we need to play next.
   int frame_index_;
 
-  DISALLOW_COPY_AND_ASSIGN(AudioPlayer);
+  DISALLOW_COPY_AND_ASSIGN(AudioPlayerImpl);
 };
 
 }  // namespace copresence