Update the WebMediaSourceClientImpl & ChunkDemuxer to received explicit end of stream cancellation.

media/filters/source_buffer_stream.h

Index: media/filters/source_buffer_stream.h
diff --git a/media/filters/source_buffer_stream.h b/media/filters/source_buffer_stream.h
index fae5e5cbb2d5bdb11d312f50c4f45bbcaab967d3..b372e13dd0fda799965f7d170b9c7ff8e1e7ece1 100644
--- a/media/filters/source_buffer_stream.h
+++ b/media/filters/source_buffer_stream.h
@@ -90,10 +90,10 @@ class MEDIA_EXPORT SourceBufferStream {
   Ranges<base::TimeDelta> GetBufferedTime() const;
 
   // Notifies this object that end of stream has been signalled.
-  void EndOfStream();
+  void MarkEndOfStream();
 
-  // Cancel the previous end of stream notification.
-  void CancelEndOfStream();
+  // Clear the end of stream state set by MarkEndOfStream().
+  void UnmarkEndOfStream();
 
   const AudioDecoderConfig& GetCurrentAudioDecoderConfig();
   const VideoDecoderConfig& GetCurrentVideoDecoderConfig();