Introduce AudioBufferMemoryPool to avoid thrashing on audio buffers.

chromecast/media/cma/backend/alsa/audio_decoder_alsa.h

 // Copyright 2015 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 CHROMECAST_MEDIA_CMA_BACKEND_ALSA_AUDIO_DECODER_ALSA_H_
 #define CHROMECAST_MEDIA_CMA_BACKEND_ALSA_AUDIO_DECODER_ALSA_H_
 
 #include <deque>
 #include <memory>
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "chromecast/media/cma/backend/alsa/stream_mixer_alsa_input.h"
 #include "chromecast/media/cma/decoder/cast_audio_decoder.h"
 #include "chromecast/public/media/decoder_config.h"
 #include "chromecast/public/media/media_pipeline_backend.h"
 #include "chromecast/public/media/media_pipeline_device_params.h"
+#include "media/base/audio_buffer.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }  // namespace base
 
 namespace media {
 class AudioBus;
 class AudioRendererAlgorithm;
 }  // namespace media
 
@@ skipping 75 matching lines @@
   std::deque<RateShifterInfo> rate_shifter_info_;
   std::unique_ptr<::media::AudioBus> rate_shifter_output_;
 
   int64_t current_pts_;
 
   std::unique_ptr<StreamMixerAlsaInput> mixer_input_;
   RenderingDelay last_mixer_delay_;
   int64_t pending_output_frames_;
   float volume_multiplier_;
 
+  scoped_refptr<::media::AudioBufferMemoryPool> pool_;
+
   base::WeakPtrFactory<AudioDecoderAlsa> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioDecoderAlsa);
 };
 
 }  // namespace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_MEDIA_CMA_BACKEND_ALSA_AUDIO_DECODER_ALSA_H_