Introduce AudioBufferMemoryPool to avoid thrashing on audio buffers.

media/filters/android/media_codec_audio_decoder.h

 // Copyright 2016 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 MEDIA_FILTERS_ANDROID_MEDIA_CODEC_AUDIO_DECODER_H_
 #define MEDIA_FILTERS_ANDROID_MEDIA_CODEC_AUDIO_DECODER_H_
 
 #include <deque>
 #include <memory>
 #include <utility>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "media/base/android/media_codec_loop.h"
 #include "media/base/android/media_drm_bridge_cdm_context.h"
+#include "media/base/audio_buffer.h"
 #include "media/base/audio_decoder.h"
 #include "media/base/audio_decoder_config.h"
 #include "media/base/media_export.h"
 
 // MediaCodecAudioDecoder is based on Android's MediaCodec API.
 // The MediaCodec API is required to play encrypted (as in EME) content on
 // Android. It is also a way to employ hardware-accelerated decoding.
 
 // Implementation notes.
 //
@@ skipping 156 matching lines @@
   // CDM related stuff.
 
   // CDM context that knowns about MediaCrypto. Owned by CDM which is external
   // to this decoder.
   MediaDrmBridgeCdmContext* media_drm_bridge_cdm_context_;
 
   // MediaDrmBridge requires registration/unregistration of the player, this
   // registration id is used for this.
   int cdm_registration_id_;
 
+  // Pool which helps avoid thrashing memory when returning audio buffers.
+  scoped_refptr<AudioBufferMemoryPool> pool_;
+
   // The MediaCrypto object is used in the MediaCodec.configure() in case of
   // an encrypted stream.
   media::MediaDrmBridgeCdmContext::JavaObjectPtr media_crypto_;
 
   base::WeakPtrFactory<MediaCodecAudioDecoder> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaCodecAudioDecoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_ANDROID_MEDIA_CODEC_AUDIO_DECODER_H_