Chrome-side implementation of media source timestamp offset

media/webm/webm_cluster_parser.h

Index: media/webm/webm_cluster_parser.h
diff --git a/media/webm/webm_cluster_parser.h b/media/webm/webm_cluster_parser.h
index 0af03617fbf57b3719abf907959c47f0af4b4cc3..be09008e08a3aa65dd01b496f23e028399cf6dc1 100644
--- a/media/webm/webm_cluster_parser.h
+++ b/media/webm/webm_cluster_parser.h
@@ -40,6 +40,13 @@ class MEDIA_EXPORT WebMClusterParser : public WebMParserClient {
   const BufferQueue& audio_buffers() const { return audio_.buffers(); }
   const BufferQueue& video_buffers() const { return video_.buffers(); }
 
+  // Tells the parser to apply |offset| to the timestamp of the next buffers it
+  // parses.
+  void SetTimestampOffset(base::TimeDelta offset);
+
+  // Resets |timestamp_offset_|.
+  void ClearTimestampOffset();
+
  private:
   // Helper class that manages per-track state.
   class Track {
@@ -88,6 +95,9 @@ class MEDIA_EXPORT WebMClusterParser : public WebMParserClient {
   Track audio_;
   Track video_;
 
+  // An offset to apply to the timestamp of each buffer.
+  base::TimeDelta timestamp_offset_;
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(WebMClusterParser);
 };