Add the copresence DirectiveHandler.

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_
+#define COMPONENTS_COPRESENCE_MEDIUMS_AUDIO_AUDIO_PLAYER_
+
+#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 {
+ public:
+  AudioPlayer();
+
+  // Initializes the object. Do not use this object before calling this method.
+  void Initialize();
+
+  // Play the given samples. These samples will keep on being played in a loop
+  // till we explicitly tell the player to stop playing.
+  void Play(const scoped_refptr<media::AudioBusRefCounted>& samples);

[Daniel Erat, 2014/08/05 16:38:52]

nit: add a blank line after this line

[rkc, 2014/08/05 18:00:35]

Done.

+  // Stop playing.
+  void Stop();
+
+  // Cleans up and deletes this object. Do not use object after this call.
+  void Finalize();
+
+  // 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);
+  }
+
+ private:
+  friend class AudioPlayerTest;
+  FRIEND_TEST_ALL_PREFIXES(AudioPlayerTest, BasicPlayAndStop);
+  FRIEND_TEST_ALL_PREFIXES(AudioPlayerTest, OutOfOrderPlayAndStopMultiple);
+
+  virtual ~AudioPlayer();
+
+  // 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:
+  // Following methods could be called from *ANY* thread.
+  virtual int OnMoreData(media::AudioBus* dest,
+                         media::AudioBuffersState /* state */) OVERRIDE;
+  virtual void OnError(media::AudioOutputStream* /* stream */) OVERRIDE;
+
+  // Flushes the audio loop, making sure that any queued operations are
+  // performed.
+  void FlushAudioLoopForTesting();
+
+  // Self-deleting object.
+  media::AudioOutputStream* stream_;
+
+  scoped_ptr<media::AudioOutputStream> output_stream_for_testing_;
+
+  bool is_playing_;
+
+  // 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);
+};
+
+}  // namespace copresence
+
+#endif  // COMPONENTS_COPRESENCE_MEDIUMS_AUDIO_AUDIO_PLAYER_