Decide the key frame directly when auto_key is off
Decide the key frame directly when auto_key is off

Change-Id: I41d107558a8b1d31ef3b263ecc0ec1e1d91c8f7e

webmproject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx