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 04a39e57d40b9a94d1f6b75d0ba213ab3ff357bb..69f6c969ab0ebbbbb98e9e7122e6d1d55e70b643 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_config.h"
 #include "media/base/video_decoder_config.h"
 #include "media/filters/blocking_url_protocol.h"
 
@@ -93,6 +94,12 @@ class FFmpegDemuxerStream : public DemuxerStream {
   // Returns true if this stream has capacity for additional data.
   bool HasAvailableCapacity();
 
+  TextKind GetTextKind() const;
+
+  // Returns the value associated with |key| in the metadata for the avstream.
+  // Returns an empty string if the key is not present.
+  std::string GetMetadata(const char* key) const;
+
  private:
   friend class FFmpegDemuxerTest;
 
@@ -136,7 +143,8 @@ class MEDIA_EXPORT FFmpegDemuxer : public Demuxer {
 
   // Demuxer implementation.
   virtual void Initialize(DemuxerHost* host,
-                          const PipelineStatusCB& status_cb) OVERRIDE;
+                          const PipelineStatusCB& status_cb,
+                          bool enable_text_tracks) OVERRIDE;
   virtual void Stop(const base::Closure& callback) OVERRIDE;
   virtual void Seek(base::TimeDelta time, const PipelineStatusCB& cb) OVERRIDE;
   virtual void OnAudioRendererDisabled() OVERRIDE;
@@ -184,6 +192,10 @@ class MEDIA_EXPORT FFmpegDemuxer : public Demuxer {
   // FFmpegDemuxerStream.
   FFmpegDemuxerStream* GetFFmpegStream(DemuxerStream::Type type) const;
 
+  // Called after the streams have been collected from the media, to allow
+  // the text renderer to bind each text stream to the cue rendering engine.
+  void AddTextStreams();
+
   DemuxerHost* host_;
 
   scoped_refptr<base::MessageLoopProxy> message_loop_;
@@ -233,6 +245,9 @@ class MEDIA_EXPORT FFmpegDemuxer : public Demuxer {
   // drops packets destined for AUDIO demuxer streams on the floor).
   bool audio_disabled_;
 
+  // Whether text streams have been enabled for this demuxer.
+  bool text_enabled_;
+
   // Set if we know duration of the audio stream. Used when processing end of
   // stream -- at this moment we definitely know duration.
   bool duration_known_;