Add mutex initialization in encoder
Add mutex initialization in encoder

This resolves the encoder crashes on windows.

Change-Id: I159d79014cf9279751e403936ce1f84482ae82da

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