Keep metric log only for the displayable frames
Keep metric log only for the displayable frames

The end-to-end reconstruction quality is represented only by the
displayable frames. Drop the coding stats from ARF frames.

Change-Id: Ib8241db448611f4b6477f107930eaa273f960e20

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