And allow the frame to recode when the frame size is larger
than the input max frame size.
If the max frame size is not specified, let vp9 decide whether
to recode. The recode follows the vp9's current recoding mechanism.
The rate control api will return the new qindex back to the
external model.
Change-Id: I796fbf713ad50a5b413b0e2501583b565ed2343f
Fix three bugs along the way.
1) Call vp9_extrc_send_firstpass_stats() after vp9_extrc_create()
2) Pass in model pointer in vp9_extrc_create()
3) Free frame_stats buffer in vp9_extrc_delete()
Bug: webm:1707
Change-Id: Ic8bd62c7b4ebd85a7479ae5e4c82d7f6059d782f
