Render inband text tracks in the media pipeline

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 7304beab2446aea9cf12b3e6538d1f35c5332fcd..c39836184222a334cda47c9e2c56fbcde5e8ec55 100644
--- a/media/filters/ffmpeg_demuxer.h
+++ b/media/filters/ffmpeg_demuxer.h
@@ -34,6 +34,7 @@
 #include "media/base/decoder_buffer_queue.h"
 #include "media/base/demuxer.h"
 #include "media/base/pipeline.h"
+#include "media/base/text_track.h"
 #include "media/base/video_decoder_config.h"
 #include "media/filters/blocking_url_protocol.h"
 
@@ -44,6 +45,13 @@ struct AVStream;
 
 namespace media {
 
+// Indicate to the player that an inband text track has been detected in
+// the media. The |index| refers to the index of the stream.
+typedef base::Callback<void(TextKind kind,
+                            const std::string& label,
+                            const std::string& language,
+                            int index)> FFmpegAddTextTrackCB;
+
 class MediaLog;
 class FFmpegDemuxer;
 class FFmpegGlue;
@@ -131,6 +139,7 @@ class MEDIA_EXPORT FFmpegDemuxer : public Demuxer {
   FFmpegDemuxer(const scoped_refptr<base::MessageLoopProxy>& message_loop,
                 DataSource* data_source,
                 const NeedKeyCB& need_key_cb,
+                const FFmpegAddTextTrackCB& add_text_track_cb,
                 const scoped_refptr<MediaLog>& media_log);
   virtual ~FFmpegDemuxer();
 
@@ -142,6 +151,8 @@ class MEDIA_EXPORT FFmpegDemuxer : public Demuxer {
   virtual void OnAudioRendererDisabled() OVERRIDE;
   virtual void SetPlaybackRate(float playback_rate) OVERRIDE;
   virtual DemuxerStream* GetStream(DemuxerStream::Type type) OVERRIDE;
+  virtual int GetStreamCount() const OVERRIDE;
+  virtual DemuxerStream* GetStreamByIndex(int index) OVERRIDE;
   virtual base::TimeDelta GetStartTime() const OVERRIDE;
 
   // Calls |need_key_cb_| with the initialization data encountered in the file.
@@ -243,6 +254,7 @@ class MEDIA_EXPORT FFmpegDemuxer : public Demuxer {
   scoped_ptr<FFmpegGlue> glue_;
 
   const NeedKeyCB need_key_cb_;
+  const FFmpegAddTextTrackCB add_text_track_cb_;
 
   DISALLOW_COPY_AND_ASSIGN(FFmpegDemuxer);
 };