vp9-dynamic resize: On a resize trigger frame refresh alt_ref.
vp9-dynamic resize: On a resize trigger frame refresh alt_ref.

For 1 pass real-time mode. No change in behavior as only last
and golden are used as references in 1 pass real-time mode.

Change-Id: Ie4655014eee1a8b271542f29d74b2c6f7fed54c9

luctrudeau/aom,ittiamvpx/libvpx-1,mbebenita/aom,mwgoldsmith/vpx,ittiamvpx/libvpx-1,ShiftMediaProject/libvpx,smarter/aom,mwgoldsmith/libvpx,GrokImageCompression/aom,mbebenita/aom,webmproject/libvpx,Topopiccione/libvpx,ShiftMediaProject/libvpx,Topopiccione/libvpx,GrokImageCompression/aom,ShiftMediaProject/libvpx,smarter/aom,mwgoldsmith/libvpx,mwgoldsmith/vpx,GrokImageCompression/aom,Topopiccione/libvpx,mbebenita/aom,mwgoldsmith/libvpx,webmproject/libvpx,GrokImageCompression/aom,webmproject/libvpx,mwgoldsmith/libvpx,mbebenita/aom,mwgoldsmith/vpx,smarter/aom,ShiftMediaProject/libvpx,ittiamvpx/libvpx-1,luctrudeau/aom,mwgoldsmith/libvpx,mbebenita/aom,ShiftMediaProject/libvpx,mwgoldsmith/vpx,ittiamvpx/libvpx-1,mwgoldsmith/vpx,luctrudeau/aom,webmproject/libvpx,mbebenita/aom,luctrudeau/aom,smarter/aom,smarter/aom,luctrudeau/aom,smarter/aom,mbebenita/aom,webmproject/libvpx,mbebenita/aom,mbebenita/aom,GrokImageCompression/aom,GrokImageCompression/aom,ittiamvpx/libvpx-1,webmproject/libvpx,mwgoldsmith/libvpx,mwgoldsmith/vpx,ittiamvpx/libvpx-1,Topopiccione/libvpx,Topopiccione/libvpx,luctrudeau/aom,Topopiccione/libvpx