Enable round-tripping and updating of WebSourceBufferImpl timestamp offset

media/filters/chunk_demuxer.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_FILTERS_CHUNK_DEMUXER_H_
 #define MEDIA_FILTERS_CHUNK_DEMUXER_H_
 
 #include <map>
 #include <string>
 #include <utility>
@@ skipping 81 matching lines @@
                std::vector<std::string>& codecs);
 
   // Removed an ID & associated resources that were previously added with
   // AddId().
   void RemoveId(const std::string& id);
 
   // Gets the currently buffered ranges for the specified ID.
   Ranges<base::TimeDelta> GetBufferedRanges(const std::string& id) const;
 
   // Appends media data to the source buffer associated with |id|.
-  void AppendData(const std::string& id, const uint8* data, size_t length);
+  // Appending may update |*timestamp_offset| if |timestamp_offset| is not NULL.
+  void AppendData(const std::string& id, const uint8* data, size_t length,
+                  double* timestamp_offset);
 
   // Aborts parsing the current segment and reset the parser to a state where
   // it can accept a new segment.
   void Abort(const std::string& id);
 
   // Remove buffers between |start| and |end| for the source buffer
   // associated with |id|.
   void Remove(const std::string& id, base::TimeDelta start,
               base::TimeDelta end);
 
@@ skipping 160 matching lines @@
   // removed with RemoveID() but can not be re-added (yet).
   std::string source_id_audio_;
   std::string source_id_video_;
 
   DISALLOW_COPY_AND_ASSIGN(ChunkDemuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_CHUNK_DEMUXER_H_