Render inband text tracks in the media pipeline

media/base/demuxer.h

Index: media/base/demuxer.h
diff --git a/media/base/demuxer.h b/media/base/demuxer.h
index a2dad22d67cb28c6085bef3353443693b0ab08e6..50968686031954475a33f753d06ce7e0d42abc91 100644
--- a/media/base/demuxer.h
+++ b/media/base/demuxer.h
@@ -15,6 +15,8 @@
 
 namespace media {
 
+class TextTrackConfig;
+
 class MEDIA_EXPORT DemuxerHost : public DataSourceHost {
  public:
   // Sets the duration of the media in microseconds.
@@ -25,6 +27,13 @@ class MEDIA_EXPORT DemuxerHost : public DataSourceHost {
   // method with PIPELINE_OK.
   virtual void OnDemuxerError(PipelineStatus error) = 0;
 
+  // Add |text_stream| to the collection managed by the text renderer.
+  virtual void AddTextStream(DemuxerStream* text_stream,
+                             const TextTrackConfig& config) = 0;
+
+  // Remove |text_stream| from the presentation.
+  virtual void RemoveTextStream(DemuxerStream* text_stream) = 0;
+
  protected:
   virtual ~DemuxerHost();
 };
@@ -66,7 +75,8 @@ class MEDIA_EXPORT Demuxer {
   // TODO(scherkus): this might not be needed http://crbug.com/234708
   virtual void OnAudioRendererDisabled() = 0;
 
-  // Returns the given stream type, or NULL if that type is not present.
+  // Returns the first stream of the given stream type (which is not allowed
+  // to be DemuxerStream::TEXT), or NULL if that type of stream is not present.
   virtual DemuxerStream* GetStream(DemuxerStream::Type type) = 0;
 
   // Returns the starting time for the media file.