Redesign the copresence audio handlers.

components/copresence/mediums/audio/audio_player.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_H_
 #define COMPONENTS_COPRESENCE_MEDIUMS_AUDIO_AUDIO_PLAYER_H_
 
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "media/audio/audio_io.h"
 
 namespace media {
 class AudioBus;
 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;
 
-  bool IsPlaying();
+  virtual bool IsPlaying() = 0;
+
+ protected:
+  virtual ~AudioPlayer() {}
+};
+
+// 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(
       media::AudioOutputStream* output_stream_for_testing) {
     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();
   void PlayOnAudioThread(
       const scoped_refptr<media::AudioBusRefCounted>& samples);
   void StopOnAudioThread();
   void StopAndCloseOnAudioThread();
   void FinalizeOnAudioThread();
 
   // AudioOutputStream::AudioSourceCallback overrides:
@@ skipping 14 matching lines @@
   scoped_ptr<media::AudioOutputStream> output_stream_for_testing_;
 
   // All fields below here are protected by this lock.
   base::Lock state_lock_;
 
   scoped_refptr<media::AudioBusRefCounted> samples_;
 
   // 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
 
 #endif  // COMPONENTS_COPRESENCE_MEDIUMS_AUDIO_AUDIO_PLAYER_H_