Stop audio FFmpegDemuxerStreams if we get notified that audio rendering is disabled.

media/filters/ffmpeg_demuxer.h

Index: media/filters/ffmpeg_demuxer.h
diff --git a/media/filters/ffmpeg_demuxer.h b/media/filters/ffmpeg_demuxer.h
index 36304814657cf6b670babfd02fdfcea1c9db1e36..df90f0a6d064b3a73f500ca67aa83e6a7e1cbe55 100644
--- a/media/filters/ffmpeg_demuxer.h
+++ b/media/filters/ffmpeg_demuxer.h
@@ -69,6 +69,9 @@ class FFmpegDemuxerStream : public DemuxerStream {
   // Returns the duration of this stream.
   base::TimeDelta duration();
 
+  // Returns the AVStream index this object is encapsulating.
+  int stream_index();
+
   // DemuxerStream implementation.
   virtual Type type() OVERRIDE;
 
@@ -217,12 +220,8 @@ class MEDIA_EXPORT FFmpegDemuxer : public Demuxer, public FFmpegURLProtocol {
   // FFmpeg context handle.
   AVFormatContext* format_context_;
 
-  // Two vector of streams:
-  //   - |streams_| is indexed by type for the Demuxer interface GetStream(),
-  //     and contains NULLs for types which aren't present.
-  //   - |packet_streams_| is indexed to mirror AVFormatContext when dealing
-  //     with AVPackets returned from av_read_frame() and contain NULL entries
-  //     representing unsupported streams where we throw away the data.
+  // |streams_| is indexed by type for the Demuxer interface GetStream(),
+  // and contains NULLs for types which aren't present.
   //
   // Ownership is handled via reference counting.
   //
@@ -230,7 +229,6 @@ class MEDIA_EXPORT FFmpegDemuxer : public Demuxer, public FFmpegURLProtocol {
   // on the demuxer thread.
   typedef std::vector< scoped_refptr<FFmpegDemuxerStream> > StreamVector;
   StreamVector streams_;
-  StreamVector packet_streams_;
 
   // Reference to the data source. Asynchronous read requests are submitted to
   // this object.