Add timelineOffset() support to WebMediaPlayerAndroid.

content/renderer/media/android/media_source_delegate.h

Index: content/renderer/media/android/media_source_delegate.h
diff --git a/content/renderer/media/android/media_source_delegate.h b/content/renderer/media/android/media_source_delegate.h
index d7e6ddc15950576b5d65b08c756a920054f934e2..4ac8ed8ade2fdaaed8277f7d3519323b39039f6b 100644
--- a/content/renderer/media/android/media_source_delegate.h
+++ b/content/renderer/media/android/media_source_delegate.h
@@ -106,6 +106,9 @@ class MediaSourceDelegate : public media::DemuxerHost {
   // Called on the main thread to check whether the video stream is encrypted.
   bool IsVideoEncrypted();
 
+  // Gets the ChunkDemuxer timeline offset.
+  base::Time GetTimelineOffset() const;
+
  private:
   // This is private to enforce use of the Destroyer.
   virtual ~MediaSourceDelegate();