Remove some unused structs and members from the decoder.
Remove some unused structs and members from the decoder.

Change-Id: Ie309cb1f683a51c5dfac405fb32e8e2d6ee143ed

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