Enable seek in fullscreen mode for MSE impl on android

media/base/android/media_player_manager.h

Index: media/base/android/media_player_manager.h
diff --git a/media/base/android/media_player_manager.h b/media/base/android/media_player_manager.h
index bef25e5b36f66ab2bcdd71b86eca91213b5a070e..71e7271295679b39f27b8b955b8fa750c5d970eb 100644
--- a/media/base/android/media_player_manager.h
+++ b/media/base/android/media_player_manager.h
@@ -68,6 +68,10 @@ class MEDIA_EXPORT MediaPlayerManager {
   // Callback when DemuxerStreamPlayer wants to read data from the demuxer.
   virtual void OnReadFromDemuxer(
       int player_id, media::DemuxerStream::Type type, bool seek_done) = 0;
+
+  // Called when player wants the media element to initiate a seek.
+  virtual void OnMediaSeekRequest(int player_id,
+                                  base::TimeDelta time_to_seek) = 0;
 };
 
 }  // namespace media