Implementing right flushing for simple_encoder.
Implementing right flushing for simple_encoder.

simple_encoder: Flush encoder. According to the current API spec we need
to call vpx_codec_encode() until vpx_codec_get_cx_data() returns NULL.

Change-Id: Ibc37706e5257a3d51e5421ca17f77ab41249d9b5

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