Add live mode detection in WebM MediaSource parser.

media/filters/chunk_demuxer.h

Index: media/filters/chunk_demuxer.h
diff --git a/media/filters/chunk_demuxer.h b/media/filters/chunk_demuxer.h
index 38e35219e353220c61635fb16675c55a4eb88bdd..a51120b2b4dd9ceb0558518a08a45d324f663374 100644
--- a/media/filters/chunk_demuxer.h
+++ b/media/filters/chunk_demuxer.h
@@ -159,6 +159,7 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
   virtual DemuxerStream* GetStream(DemuxerStream::Type type) OVERRIDE;
   virtual base::TimeDelta GetStartTime() const OVERRIDE;
   virtual base::Time GetTimelineOffset() const OVERRIDE;
+  virtual bool IsLiveMode() const OVERRIDE;
 
   // Methods used by an external object to control this demuxer.
   //
@@ -366,6 +367,7 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
   double user_specified_duration_;
 
   base::Time timeline_offset_;
+  bool live_mode_;
 
   typedef std::map<std::string, SourceState*> SourceStateMap;
   SourceStateMap source_state_map_;