Add Stop() to AudioDecoder.

media/base/audio_decoder.h

 // Copyright (c) 2012 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_DECODER_H_
 #define MEDIA_BASE_AUDIO_DECODER_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "media/base/channel_layout.h"
@@ skipping 31 matching lines @@
   // this method.
   //
   // Non-NULL sample buffer pointers will contain decoded audio data or may
   // indicate the end of the stream. A NULL buffer pointer indicates an aborted
   // Read(). This can happen if the DemuxerStream gets flushed and doesn't have
   // any more data to return.
   typedef base::Callback<void(Status, const scoped_refptr<AudioBuffer>&)>
       ReadCB;
   virtual void Read(const ReadCB& read_cb) = 0;
 
   // Reset decoder state, dropping any queued encoded data.

[xhwang, 2014/01/08 01:33:37]

nit: since you are here, s/Reset/Resets, same as Initialize on l.31 and Request
on l.38. thanks!

   virtual void Reset(const base::Closure& closure) = 0;
 
+  // Stops decoder, fires any pending callbacks and sets the decoder to an
+  // uninitialized state. An AudioDecoder cannot be re-initialized after it has
+  // been stopped.
+  // Note that if Initialize() has been called, Stop() must be called and
+  // complete before deleting the decoder.
+  virtual void Stop(const base::Closure& closure) = 0;
+
   // Returns various information about the decoded audio format.
   virtual int bits_per_channel() = 0;
   virtual ChannelLayout channel_layout() = 0;
   virtual int samples_per_second() = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AudioDecoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_DECODER_H_