auto merge of #5221 : andreastt/servo/ato/wpt-bootstrap, r=Manishearth
auto merge of #5221 : andreastt/servo/ato/wpt-bootstrap, r=Manishearth

`./mach test-wpt` will fail in non-obvious ways unless all wpt submodules have recursively been checked out first.  This ensure they have been when running the command in a checkout of Servo that hasn't been bootstrapped yet.

peterjoel/servo,zhangjunlei26/servo,samfoo/servo,szeged/servo,aidanhs/servo,paulrouget/servo,fiji-flo/servo,emilio/servo,emilio/servo,snf/servo,zhangjunlei26/servo,paulrouget/servo,brendandahl/servo,deokjinkim/servo,splav/servo,DominoTree/servo,saratang/servo,tempbottle/servo,jimberlage/servo,steveklabnik/servo,nrc/servo,mattnenterprise/servo,CJ8664/servo,rentongzhang/servo,CJ8664/servo,jlegendary/servo,KiChjang/servo,cbrewster/servo,codemac/servo,boghison/servo,tschneidereit/servo,WriterOfAlicrow/servo,DominoTree/servo,jimberlage/servo,youprofit/servo,larsbergstrom/servo,dati91/servo,jgraham/servo,dati91/servo,dagnir/servo,eddyb/servo,canaltinova/servo,wartman4404/servo,g-k/servo,brendandahl/servo,caldwell/servo,dvberkel/servo,samfoo/servo,kindersung/servo,KiChjang/servo,pyecs/servo,deokjinkim/servo,splav/servo,saratang/servo,pyecs/servo,saratang/servo,larsbergstrom/servo,nick-thompson/servo,vks/servo,sadmansk/servo,walac/servo,saneyuki/servo,upsuper/servo,jimberlage/servo,jgraham/servo,RenaudParis/servo,pyecs/servo,indykish/servo,s142857/servo,SimonSapin/servo,nnethercote/servo,snf/servo,sadmansk/servo,akosel/servo,mdibaiee/servo,jimberlage/servo,emilio/servo,DominoTree/servo,ryancanhelpyou/servo,upsuper/servo,caldwell/servo,GyrosOfWar/servo,anthgur/servo,canaltinova/servo,peterjoel/servo,szeged/servo,brendandahl/servo,mt2d2/servo,evilpie/servo,thiagopnts/servo,GyrosOfWar/servo,A-deLuna/servo,rentongzhang/servo,rixrix/servo,saneyuki/servo,pyfisch/servo,thiagopnts/servo,rnestler/servo,rentongzhang/servo,anthgur/servo,nerith/servo,tempbottle/servo,g-k/servo,dati91/servo,aidanhs/servo,cbrewster/servo,meh/servo,s142857/servo,j3parker/servo,bjwbell/servo,sadmansk/servo,GreenRecycleBin/servo,notriddle/servo,notriddle/servo,indykish/servo,jimberlage/servo,wartman4404/servo,codemac/servo,echochamber/servo,szeged/servo,wpgallih/servo,mdibaiee/servo,vks/servo,meh/servo,tempbottle/servo,pyfisch/servo,notriddle/servo,echochamber/servo,tempbottle/servo,saneyuki/servo,notriddle/servo,indykish/servo,anthgur/servo,DominoTree/servo,brendandahl/servo,SimonSapin/servo,paulrouget/servo,ConnorGBrewster/servo,dsandeephegde/servo,paulrouget/servo,zhangjunlei26/servo,snf/servo,nick-thompson/servo,RenaudParis/servo,zentner-kyle/servo,szeged/servo,kindersung/servo,youprofit/servo,ConnorGBrewster/servo,paulrouget/servo,wpgallih/servo,Adenilson/prototype-viewing-distance,GreenRecycleBin/servo,mdibaiee/servo,eddyb/servo,rixrix/servo,cbrewster/servo,g-k/servo,DominoTree/servo,mattnenterprise/servo,sadmansk/servo,nrc/servo,aidanhs/servo,pyecs/servo,canaltinova/servo,KiChjang/servo,saneyuki/servo,aidanhs/servo,thiagopnts/servo,huonw/servo,splav/servo,akosel/servo,dhananjay92/servo,upsuper/servo,ryancanhelpyou/servo,szeged/servo,szeged/servo,upsuper/servo,wpgallih/servo,A-deLuna/servo,anthgur/servo,KiChjang/servo,srbhklkrn/SERVOENGINE,aweinstock314/servo,samfoo/servo,paulrouget/servo,GreenRecycleBin/servo,deokjinkim/servo,dsandeephegde/servo,avadacatavra/servo,jgraham/servo,AnthonyBroadCrawford/servo,jimberlage/servo,thiagopnts/servo,tafia/servo,mbrubeck/servo,mbrubeck/servo,emilio/servo,jdramani/servo,huonw/servo,WriterOfAlicrow/servo,dvberkel/servo,ConnorGBrewster/servo,srbhklkrn/SERVOENGINE,s142857/servo,runarberg/servo,tafia/servo,meh/servo,nerith/servo,avadacatavra/servo,cbrewster/servo,CJ8664/servo,dsandeephegde/servo,A-deLuna/servo,echochamber/servo,GyrosOfWar/servo,pyfisch/servo,splav/servo,hyowon/servo,tschneidereit/servo,thiagopnts/servo,anthgur/servo,codemac/servo,walac/servo,dvberkel/servo,rentongzhang/servo,fiji-flo/servo,fiji-flo/servo,tafia/servo,dvberkel/servo,nnethercote/servo,dagnir/servo,DominoTree/servo,dhananjay92/servo,KiChjang/servo,zentner-kyle/servo,bjwbell/servo,KiChjang/servo,zentner-kyle/servo,GreenRecycleBin/servo,tafia/servo,ryancanhelpyou/servo,meh/servo,echochamber/servo,steveklabnik/servo,RenaudParis/servo,mdibaiee/servo,splav/servo,canaltinova/servo,rnestler/servo,hyowon/servo,kindersung/servo,emilio/servo,pyfisch/servo,hyowon/servo,eddyb/servo,notriddle/servo,mattnenterprise/servo,upsuper/servo,bjwbell/servo,evilpie/servo,pyecs/servo,wpgallih/servo,huonw/servo,szeged/servo,aidanhs/servo,Adenilson/prototype-viewing-distance,g-k/servo,j3parker/servo,dati91/servo,paulrouget/servo,indykish/servo,sadmansk/servo,pgonda/servo,anthgur/servo,zentner-kyle/servo,saneyuki/servo,deokjinkim/servo,samfoo/servo,ryancanhelpyou/servo,jdramani/servo,youprofit/servo,pgonda/servo,jlegendary/servo,dhananjay92/servo,Adenilson/prototype-viewing-distance,avadacatavra/servo,rixrix/servo,AnthonyBroadCrawford/servo,eddyb/servo,dhananjay92/servo,s142857/servo,pgonda/servo,saneyuki/servo,youprofit/servo,indykish/servo,notriddle/servo,mbrubeck/servo,jdramani/servo,fiji-flo/servo,saneyuki/servo,s142857/servo,wpgallih/servo,dvberkel/servo,rnestler/servo,steveklabnik/servo,tschneidereit/servo,caldwell/servo,huonw/servo,rixrix/servo,peterjoel/servo,wartman4404/servo,emilio/servo,KiChjang/servo,dagnir/servo,fiji-flo/servo,CJ8664/servo,mattnenterprise/servo,jgraham/servo,boghison/servo,mt2d2/servo,mt2d2/servo,peterjoel/servo,pgonda/servo,ryancanhelpyou/servo,RenaudParis/servo,aweinstock314/servo,deokjinkim/servo,mbrubeck/servo,CJ8664/servo,larsbergstrom/servo,larsbergstrom/servo,pyfisch/servo,anthgur/servo,srbhklkrn/SERVOENGINE,rnestler/servo,A-deLuna/servo,j3parker/servo,mattnenterprise/servo,rentongzhang/servo,karlito40/servo,walac/servo,eddyb/servo,saratang/servo,rixrix/servo,jlegendary/servo,pyfisch/servo,upsuper/servo,nick-thompson/servo,caldwell/servo,vks/servo,caldwell/servo,ConnorGBrewster/servo,akosel/servo,sadmansk/servo,larsbergstrom/servo,AnthonyBroadCrawford/servo,dagnir/servo,dagnir/servo,AnthonyBroadCrawford/servo,AnthonyBroadCrawford/servo,A-deLuna/servo,saratang/servo,jdramani/servo,dvberkel/servo,bjwbell/servo,tempbottle/servo,GreenRecycleBin/servo,karlito40/servo,Adenilson/prototype-viewing-distance,CJ8664/servo,RenaudParis/servo,Adenilson/prototype-viewing-distance,mattnenterprise/servo,jdramani/servo,mbrubeck/servo,tschneidereit/servo,srbhklkrn/SERVOENGINE,mattnenterprise/servo,SimonSapin/servo,samfoo/servo,KiChjang/servo,j3parker/servo,szeged/servo,runarberg/servo,nnethercote/servo,splav/servo,steveklabnik/servo,rixrix/servo,aweinstock314/servo,youprofit/servo,runarberg/servo,fiji-flo/servo,bjwbell/servo,cbrewster/servo,karlito40/servo,nrc/servo,zentner-kyle/servo,avadacatavra/servo,sadmansk/servo,tempbottle/servo,meh/servo,upsuper/servo,walac/servo,nnethercote/servo,zhangjunlei26/servo,dati91/servo,jdramani/servo,nerith/servo,karlito40/servo,tschneidereit/servo,nnethercote/servo,peterjoel/servo,akosel/servo,youprofit/servo,nnethercote/servo,rnestler/servo,tempbottle/servo,avadacatavra/servo,pyfisch/servo,dvberkel/servo,karlito40/servo,WriterOfAlicrow/servo,eddyb/servo,steveklabnik/servo,mbrubeck/servo,nnethercote/servo,jgraham/servo,Adenilson/prototype-viewing-distance,splav/servo,evilpie/servo,mt2d2/servo,evilpie/servo,nick-thompson/servo,indykish/servo,DominoTree/servo,paulrouget/servo,echochamber/servo,wpgallih/servo,wartman4404/servo,GreenRecycleBin/servo,karlito40/servo,vks/servo,huonw/servo,thiagopnts/servo,saneyuki/servo,evilpie/servo,snf/servo,pyfisch/servo,j3parker/servo,kindersung/servo,aweinstock314/servo,walac/servo,fiji-flo/servo,larsbergstrom/servo,kindersung/servo,RenaudParis/servo,dsandeephegde/servo,peterjoel/servo,ConnorGBrewster/servo,GyrosOfWar/servo,zhangjunlei26/servo,cbrewster/servo,AnthonyBroadCrawford/servo,dsandeephegde/servo,DominoTree/servo,aweinstock314/servo,pyfisch/servo,mattnenterprise/servo,splav/servo,WriterOfAlicrow/servo,nick-thompson/servo,runarberg/servo,saratang/servo,ConnorGBrewster/servo,upsuper/servo,akosel/servo,thiagopnts/servo,nerith/servo,paulrouget/servo,jimberlage/servo,A-deLuna/servo,GyrosOfWar/servo,g-k/servo,caldwell/servo,nick-thompson/servo,nrc/servo,SimonSapin/servo,deokjinkim/servo,brendandahl/servo,eddyb/servo,dati91/servo,ryancanhelpyou/servo,mbrubeck/servo,saneyuki/servo,brendandahl/servo,rentongzhang/servo,avadacatavra/servo,srbhklkrn/SERVOENGINE,ConnorGBrewster/servo,dsandeephegde/servo,rixrix/servo,zentner-kyle/servo,pgonda/servo,tschneidereit/servo,rnestler/servo,eddyb/servo,emilio/servo,mt2d2/servo,rentongzhang/servo,nrc/servo,nrc/servo,GyrosOfWar/servo,mt2d2/servo,nnethercote/servo,steveklabnik/servo,indykish/servo,g-k/servo,nick-thompson/servo,meh/servo,bjwbell/servo,canaltinova/servo,tafia/servo,karlito40/servo,CJ8664/servo,tafia/servo,wartman4404/servo,rnestler/servo,ryancanhelpyou/servo,SimonSapin/servo,KiChjang/servo,GreenRecycleBin/servo,zentner-kyle/servo,pgonda/servo,avadacatavra/servo,notriddle/servo,bjwbell/servo,akosel/servo,wpgallih/servo,dsandeephegde/servo,A-deLuna/servo,zhangjunlei26/servo,notriddle/servo,DominoTree/servo,snf/servo,wartman4404/servo,boghison/servo,jlegendary/servo,paulrouget/servo,dati91/servo,nnethercote/servo,vks/servo,aweinstock314/servo,jimberlage/servo,codemac/servo,canaltinova/servo,dhananjay92/servo,walac/servo,huonw/servo,nerith/servo,szeged/servo,nerith/servo,larsbergstrom/servo,nerith/servo,echochamber/servo,wpgallih/servo,saneyuki/servo,notriddle/servo,snf/servo,sadmansk/servo,indykish/servo,jlegendary/servo,mt2d2/servo,aidanhs/servo,j3parker/servo,hyowon/servo,zhangjunlei26/servo,thiagopnts/servo,caldwell/servo,nrc/servo,GreenRecycleBin/servo,g-k/servo,evilpie/servo,kindersung/servo,j3parker/servo,larsbergstrom/servo,jlegendary/servo,emilio/servo,vks/servo,dagnir/servo,aidanhs/servo,zhangjunlei26/servo,kindersung/servo,WriterOfAlicrow/servo,brendandahl/servo,samfoo/servo,emilio/servo,wpgallih/servo,walac/servo,runarberg/servo,evilpie/servo,jdramani/servo,jlegendary/servo,deokjinkim/servo,peterjoel/servo,peterjoel/servo,splav/servo,vks/servo,canaltinova/servo,dhananjay92/servo,saratang/servo,indykish/servo,cbrewster/servo,jimberlage/servo,jgraham/servo,peterjoel/servo,AnthonyBroadCrawford/servo,wartman4404/servo,huonw/servo,snf/servo,SimonSapin/servo,hyowon/servo,boghison/servo,pgonda/servo,akosel/servo,ConnorGBrewster/servo,boghison/servo,RenaudParis/servo,pyecs/servo,s142857/servo,evilpie/servo,dati91/servo,mdibaiee/servo,dhananjay92/servo,rixrix/servo,hyowon/servo,notriddle/servo,SimonSapin/servo,srbhklkrn/SERVOENGINE,samfoo/servo,DominoTree/servo,boghison/servo,s142857/servo,CJ8664/servo,mdibaiee/servo,meh/servo,larsbergstrom/servo,hyowon/servo,zhangjunlei26/servo,boghison/servo,avadacatavra/servo,canaltinova/servo,rnestler/servo,echochamber/servo,pyecs/servo,mbrubeck/servo,codemac/servo,srbhklkrn/SERVOENGINE,aweinstock314/servo,codemac/servo,fiji-flo/servo,evilpie/servo,emilio/servo,WriterOfAlicrow/servo,pyfisch/servo,runarberg/servo,anthgur/servo,steveklabnik/servo,SimonSapin/servo,larsbergstrom/servo,KiChjang/servo,cbrewster/servo,GreenRecycleBin/servo,Adenilson/prototype-viewing-distance,jgraham/servo,mdibaiee/servo,dsandeephegde/servo,nnethercote/servo,GyrosOfWar/servo,runarberg/servo,WriterOfAlicrow/servo,tafia/servo,dagnir/servo,tschneidereit/servo,rixrix/servo,youprofit/servo,peterjoel/servo,codemac/servo,splav/servo,szeged/servo