Introduce media::AudioPushFifo and a couple of use cases (and clean-ups).

media/base/audio_block_fifo.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 MEDIA_BASE_AUDIO_BLOCK_FIFO_H_
 #define MEDIA_BASE_AUDIO_BLOCK_FIFO_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_vector.h"
 #include "media/base/audio_bus.h"
 #include "media/base/media_export.h"
 
 namespace media {
 
 // First-in first-out container for AudioBus elements.
 // The FIFO is composed of blocks of AudioBus elements, it accepts interleaved
 // data as input and will deinterleave it into the FIFO, and it only allows
 // consuming a whole block of AudioBus element.
 // This class is thread-unsafe.
+//

[DaleCurtis, 2016/02/20 00:07:22]

Do you plan to port and remove existing instances? Should we file a bug to track
this?

[miu, 2016/02/23 04:27:41]

I don't have the available cycles, myself.  I've removed these comments for now.

+// NOTE: Consider using the more-efficient and easier-to-use AudioRechunker
+// instead of this FIFO implementation.
 class MEDIA_EXPORT AudioBlockFifo {
  public:
   // Creates a new AudioBlockFifo and allocates |blocks| memory, each block
   // of memory can store |channels| of length |frames| data.
   AudioBlockFifo(int channels, int frames, int blocks);
   virtual ~AudioBlockFifo();
 
   // Pushes interleaved audio data from |source| to the FIFO.
   // The method will deinterleave the data into a audio bus.
   // Push() will crash if the allocated space is insufficient.
@@ skipping 41 matching lines @@
 
   // Current write position in the current written block.
   int write_pos_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioBlockFifo);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_BLOCK_FIFO_H_