DO NOT MERGE MPEG4Extractor: ensure kKeyTrackID exists before creating an MPEG4Source as track. am: b016207fc2
am: e2ca751723

* commit 'e2ca7517232e2df2dc16d358809d7e4723827c42':
  DO NOT MERGE MPEG4Extractor: ensure kKeyTrackID exists before creating an MPEG4Source as track.

Change-Id: Ia1dd264fc19f8c82a59a5e2656375f2c2c4403ff