Update media duration if data is appended after the previous duration

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 d480c7f0af51098b2866d6f43a23299f4623a4c6..fb2ad891b01b73d3b7cac4e95976f844d0854c05 100644
--- a/media/filters/chunk_demuxer.h
+++ b/media/filters/chunk_demuxer.h
@@ -136,6 +136,16 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
   // Returns true if |source_id| is valid, false otherwise.
   bool IsValidId(const std::string& source_id) const;
 
+  // Increases |duration_| if the newly appended |buffers| exceeds the current
+  // |duration_|.
+  void IncreaseDurationIfNecessary(const StreamParser::BufferQueue& buffers);
+
+  // Sets |duration_| to |new_duration| and notifies |host_|.
+  void UpdateDuration(base::TimeDelta new_duration);
+
+  // Returns the ranges representing the buffered data in the demuxer.
+  Ranges<base::TimeDelta> GetBufferedRanges() const;
+
   mutable base::Lock lock_;
   State state_;