Use same default window size in headless compositor
Use same default window size in headless compositor

Attempts to fix #7730.

szeged/servo,sadmansk/servo,nnethercote/servo,jimberlage/servo,nnethercote/servo,DominoTree/servo,eddyb/servo,emilio/servo,nrc/servo,nrc/servo,anthgur/servo,cbrewster/servo,szeged/servo,larsbergstrom/servo,pyfisch/servo,szeged/servo,emilio/servo,mbrubeck/servo,peterjoel/servo,SimonSapin/servo,jimberlage/servo,nrc/servo,nnethercote/servo,anthgur/servo,saneyuki/servo,paulrouget/servo,upsuper/servo,nnethercote/servo,pyfisch/servo,eddyb/servo,ConnorGBrewster/servo,fiji-flo/servo,mbrubeck/servo,jimberlage/servo,emilio/servo,rnestler/servo,DominoTree/servo,pyfisch/servo,sadmansk/servo,emilio/servo,mbrubeck/servo,DominoTree/servo,sadmansk/servo,thiagopnts/servo,canaltinova/servo,peterjoel/servo,canaltinova/servo,upsuper/servo,mattnenterprise/servo,rnestler/servo,jimberlage/servo,DominoTree/servo,ConnorGBrewster/servo,pyfisch/servo,emilio/servo,dsandeephegde/servo,sadmansk/servo,sadmansk/servo,fiji-flo/servo,DominoTree/servo,CJ8664/servo,CJ8664/servo,DominoTree/servo,pyfisch/servo,DominoTree/servo,SimonSapin/servo,splav/servo,saneyuki/servo,nnethercote/servo,CJ8664/servo,anthgur/servo,cbrewster/servo,dsandeephegde/servo,mbrubeck/servo,canaltinova/servo,larsbergstrom/servo,sadmansk/servo,pyfisch/servo,saneyuki/servo,larsbergstrom/servo,larsbergstrom/servo,ConnorGBrewster/servo,dsandeephegde/servo,larsbergstrom/servo,nrc/servo,paulrouget/servo,CJ8664/servo,nnethercote/servo,mattnenterprise/servo,thiagopnts/servo,nrc/servo,dati91/servo,steveklabnik/servo,splav/servo,mattnenterprise/servo,saneyuki/servo,upsuper/servo,notriddle/servo,saneyuki/servo,dati91/servo,peterjoel/servo,rnestler/servo,mbrubeck/servo,avadacatavra/servo,KiChjang/servo,splav/servo,KiChjang/servo,paulrouget/servo,peterjoel/servo,emilio/servo,notriddle/servo,fiji-flo/servo,fiji-flo/servo,splav/servo,eddyb/servo,steveklabnik/servo,mattnenterprise/servo,splav/servo,notriddle/servo,eddyb/servo,ConnorGBrewster/servo,SimonSapin/servo,notriddle/servo,mbrubeck/servo,dati91/servo,avadacatavra/servo,ConnorGBrewster/servo,emilio/servo,SimonSapin/servo,canaltinova/servo,larsbergstrom/servo,CJ8664/servo,saneyuki/servo,saneyuki/servo,pyfisch/servo,notriddle/servo,dsandeephegde/servo,dsandeephegde/servo,anthgur/servo,szeged/servo,jimberlage/servo,nnethercote/servo,jimberlage/servo,sadmansk/servo,steveklabnik/servo,DominoTree/servo,paulrouget/servo,SimonSapin/servo,steveklabnik/servo,thiagopnts/servo,jimberlage/servo,pyfisch/servo,KiChjang/servo,cbrewster/servo,KiChjang/servo,steveklabnik/servo,dsandeephegde/servo,dati91/servo,SimonSapin/servo,anthgur/servo,dati91/servo,ConnorGBrewster/servo,mattnenterprise/servo,cbrewster/servo,splav/servo,mbrubeck/servo,eddyb/servo,paulrouget/servo,ConnorGBrewster/servo,szeged/servo,CJ8664/servo,cbrewster/servo,fiji-flo/servo,szeged/servo,SimonSapin/servo,KiChjang/servo,anthgur/servo,KiChjang/servo,cbrewster/servo,KiChjang/servo,canaltinova/servo,avadacatavra/servo,saneyuki/servo,dsandeephegde/servo,canaltinova/servo,peterjoel/servo,upsuper/servo,nnethercote/servo,ConnorGBrewster/servo,upsuper/servo,larsbergstrom/servo,nnethercote/servo,emilio/servo,dsandeephegde/servo,notriddle/servo,saneyuki/servo,SimonSapin/servo,thiagopnts/servo,thiagopnts/servo,fiji-flo/servo,splav/servo,dati91/servo,paulrouget/servo,KiChjang/servo,szeged/servo,paulrouget/servo,fiji-flo/servo,peterjoel/servo,nnethercote/servo,dati91/servo,steveklabnik/servo,anthgur/servo,larsbergstrom/servo,CJ8664/servo,rnestler/servo,splav/servo,DominoTree/servo,anthgur/servo,jimberlage/servo,thiagopnts/servo,canaltinova/servo,nrc/servo,jimberlage/servo,upsuper/servo,cbrewster/servo,peterjoel/servo,peterjoel/servo,splav/servo,mattnenterprise/servo,rnestler/servo,paulrouget/servo,fiji-flo/servo,peterjoel/servo,rnestler/servo,avadacatavra/servo,splav/servo,DominoTree/servo,eddyb/servo,avadacatavra/servo,notriddle/servo,paulrouget/servo,sadmansk/servo,KiChjang/servo,szeged/servo,pyfisch/servo,mattnenterprise/servo,paulrouget/servo,dati91/servo,thiagopnts/servo,notriddle/servo,CJ8664/servo,steveklabnik/servo,notriddle/servo,avadacatavra/servo,avadacatavra/servo,notriddle/servo,pyfisch/servo,KiChjang/servo,eddyb/servo,mattnenterprise/servo,emilio/servo,mbrubeck/servo,saneyuki/servo,peterjoel/servo,upsuper/servo,szeged/servo,avadacatavra/servo,thiagopnts/servo,szeged/servo,canaltinova/servo,emilio/servo,eddyb/servo,cbrewster/servo,rnestler/servo,nrc/servo,upsuper/servo,rnestler/servo,larsbergstrom/servo,larsbergstrom/servo