DO NOT MERGE - MPEG4Extractor: Check mLastTrack before dereferencing. am: 0338b14e28  -s ours am: 648b682eeb am: d558903f8c  -s ours am: ad1141b06b
am: fbe82fe0fa

Change-Id: I2882ebae8b42057767a40cf65d14c177ace96200