fix an assumption about uv_stride
fix an assumption about uv_stride

Use the uv_stride from the framebuffer rather than deriving it from the
y_stride.

Change-Id: I94581cb741539d094ff062b3d008235556903b8c

webmproject/libvpx,VTCSecureLLC/libvpx,Suvarna1488/webm.libvpx,iniwf/webm.libvpx,GrokImageCompression/aom,kleopatra999/webm.libvpx,luctrudeau/aom,stewnorriss/libvpx,pcwalton/libvpx,kalli123/webm.libvpx,lyx2014/libvpx_c,n4t/libvpx,cinema6/libvpx,altogother/webm.libvpx,goodleixiao/vpx,Distrotech/libvpx,Acidburn0zzz/webm.libvpx,Laknot/libvpx,smarter/aom,luctrudeau/aom,luctrudeau/aom,felipebetancur/libvpx,running770/libvpx,jacklicn/webm.libvpx,mwgoldsmith/vpx,zofuthan/libvpx,cinema6/libvpx,kim42083/webm.libvpx,jmvalin/aom,Maria1099/webm.libvpx,jdm/libvpx,smarter/aom,thdav/aom,openpeer/libvpx_new,ittiamvpx/libvpx,cinema6/libvpx,kim42083/webm.libvpx,gshORTON/webm.libvpx,pcwalton/libvpx,iniwf/webm.libvpx,iniwf/webm.libvpx,felipebetancur/libvpx,WebRTC-Labs/libvpx,gshORTON/webm.libvpx,mbebenita/aom,shareefalis/libvpx,matanbs/vp982,lyx2014/libvpx_c,lyx2014/libvpx_c,ittiamvpx/libvpx,reimaginemedia/webm.libvpx,matanbs/webm.libvpx,ShiftMediaProject/libvpx,Distrotech/libvpx,mbebenita/aom,reimaginemedia/webm.libvpx,liqianggao/libvpx,felipebetancur/libvpx,ittiamvpx/libvpx-1,running770/libvpx,sanyaade-teachings/libvpx,vasilvv/esvp8,hsueceumd/test_hui,gshORTON/webm.libvpx,iniwf/webm.libvpx,abwiz0086/webm.libvpx,Maria1099/webm.libvpx,goodleixiao/vpx,Suvarna1488/webm.libvpx,Maria1099/webm.libvpx,turbulenz/libvpx,thdav/aom,hsueceumd/test_hui,matanbs/vp982,turbulenz/libvpx,VTCSecureLLC/libvpx,turbulenz/libvpx,stewnorriss/libvpx,shyamalschandra/libvpx,jdm/libvpx,n4t/libvpx,WebRTC-Labs/libvpx,mbebenita/aom,turbulenz/libvpx,matanbs/webm.libvpx,GrokImageCompression/aom,felipebetancur/libvpx,shacklettbp/aom,hsueceumd/test_hui,ittiamvpx/libvpx-1,Suvarna1488/webm.libvpx,Suvarna1488/webm.libvpx,ittiamvpx/libvpx,Distrotech/libvpx,mbebenita/aom,n4t/libvpx,kleopatra999/webm.libvpx,jmvalin/aom,sanyaade-teachings/libvpx,goodleixiao/vpx,matanbs/webm.libvpx,vasilvv/esvp8,ittiamvpx/libvpx-1,jdm/libvpx,shacklettbp/aom,smarter/aom,Laknot/libvpx,kim42083/webm.libvpx,stewnorriss/libvpx,gshORTON/webm.libvpx,zofuthan/libvpx,VTCSecureLLC/libvpx,Maria1099/webm.libvpx,ittiamvpx/libvpx-1,reimaginemedia/webm.libvpx,zofuthan/libvpx,pcwalton/libvpx,zofuthan/libvpx,goodleixiao/vpx,felipebetancur/libvpx,lyx2014/libvpx_c,shareefalis/libvpx,ShiftMediaProject/libvpx,turbulenz/libvpx,charup/https---github.com-webmproject-libvpx-,mwgoldsmith/libvpx,matanbs/vp982,ittiamvpx/libvpx,openpeer/libvpx_new,Maria1099/webm.libvpx,shacklettbp/aom,jacklicn/webm.libvpx,webmproject/libvpx,lyx2014/libvpx_c,VTCSecureLLC/libvpx,Maria1099/webm.libvpx,abwiz0086/webm.libvpx,webmproject/libvpx,shareefalis/libvpx,charup/https---github.com-webmproject-libvpx-,altogother/webm.libvpx,ittiamvpx/libvpx-1,jmvalin/aom,GrokImageCompression/aom,abwiz0086/webm.libvpx,jdm/libvpx,openpeer/libvpx_new,pcwalton/libvpx,goodleixiao/vpx,GrokImageCompression/aom,Topopiccione/libvpx,Laknot/libvpx,smarter/aom,mwgoldsmith/vpx,liqianggao/libvpx,webmproject/libvpx,GrokImageCompression/aom,mbebenita/aom,jacklicn/webm.libvpx,Suvarna1488/webm.libvpx,n4t/libvpx,kalli123/webm.libvpx,Laknot/libvpx,kim42083/webm.libvpx,mwgoldsmith/libvpx,sanyaade-teachings/libvpx,Acidburn0zzz/webm.libvpx,goodleixiao/vpx,zofuthan/libvpx,mbebenita/aom,kalli123/webm.libvpx,n4t/libvpx,turbulenz/libvpx,shareefalis/libvpx,luctrudeau/aom,openpeer/libvpx_new,thdav/aom,mwgoldsmith/libvpx,turbulenz/libvpx,cinema6/libvpx,jmvalin/aom,luctrudeau/aom,running770/libvpx,jacklicn/webm.libvpx,abwiz0086/webm.libvpx,vasilvv/esvp8,Topopiccione/libvpx,Topopiccione/libvpx,Distrotech/libvpx,kleopatra999/webm.libvpx,cinema6/libvpx,gshORTON/webm.libvpx,abwiz0086/webm.libvpx,jdm/libvpx,mbebenita/aom,Distrotech/libvpx,Topopiccione/libvpx,shacklettbp/aom,Suvarna1488/webm.libvpx,shareefalis/libvpx,smarter/aom,ShiftMediaProject/libvpx,matanbs/webm.libvpx,mwgoldsmith/libvpx,matanbs/vp982,mwgoldsmith/libvpx,gshORTON/webm.libvpx,cinema6/libvpx,iniwf/webm.libvpx,Topopiccione/libvpx,kleopatra999/webm.libvpx,cinema6/libvpx,mwgoldsmith/vpx,thdav/aom,shyamalschandra/libvpx,Acidburn0zzz/webm.libvpx,WebRTC-Labs/libvpx,altogother/webm.libvpx,vasilvv/esvp8,pcwalton/libvpx,altogother/webm.libvpx,running770/libvpx,shyamalschandra/libvpx,webmproject/libvpx,kleopatra999/webm.libvpx,vasilvv/esvp8,mwgoldsmith/vpx,shyamalschandra/libvpx,shacklettbp/aom,pcwalton/libvpx,ShiftMediaProject/libvpx,Acidburn0zzz/webm.libvpx,openpeer/libvpx_new,shacklettbp/aom,Topopiccione/libvpx,jacklicn/webm.libvpx,vasilvv/esvp8,abwiz0086/webm.libvpx,altogother/webm.libvpx,ittiamvpx/libvpx,matanbs/vp982,shyamalschandra/libvpx,Laknot/libvpx,liqianggao/libvpx,jmvalin/aom,charup/https---github.com-webmproject-libvpx-,reimaginemedia/webm.libvpx,ittiamvpx/libvpx,liqianggao/libvpx,altogother/webm.libvpx,ittiamvpx/libvpx-1,openpeer/libvpx_new,charup/https---github.com-webmproject-libvpx-,VTCSecureLLC/libvpx,liqianggao/libvpx,charup/https---github.com-webmproject-libvpx-,mbebenita/aom,zofuthan/libvpx,WebRTC-Labs/libvpx,mwgoldsmith/libvpx,kalli123/webm.libvpx,jacklicn/webm.libvpx,Acidburn0zzz/webm.libvpx,matanbs/vp982,hsueceumd/test_hui,kalli123/webm.libvpx,reimaginemedia/webm.libvpx,thdav/aom,mbebenita/aom,iniwf/webm.libvpx,VTCSecureLLC/libvpx,shyamalschandra/libvpx,WebRTC-Labs/libvpx,jmvalin/aom,stewnorriss/libvpx,shareefalis/libvpx,webmproject/libvpx,kim42083/webm.libvpx,Laknot/libvpx,kalli123/webm.libvpx,thdav/aom,mwgoldsmith/vpx,vasilvv/esvp8,lyx2014/libvpx_c,luctrudeau/aom,sanyaade-teachings/libvpx,sanyaade-teachings/libvpx,matanbs/webm.libvpx,turbulenz/libvpx,liqianggao/libvpx,Distrotech/libvpx,ShiftMediaProject/libvpx,turbulenz/libvpx,running770/libvpx,kleopatra999/webm.libvpx,stewnorriss/libvpx,jdm/libvpx,GrokImageCompression/aom,matanbs/webm.libvpx,matanbs/vp982,hsueceumd/test_hui,charup/https---github.com-webmproject-libvpx-,felipebetancur/libvpx,Acidburn0zzz/webm.libvpx,mwgoldsmith/vpx,reimaginemedia/webm.libvpx,running770/libvpx,kim42083/webm.libvpx,hsueceumd/test_hui,smarter/aom,stewnorriss/libvpx