Simplify ThreadSafeLayoutNodeChildrenIterator::next a bit.
Simplify ThreadSafeLayoutNodeChildrenIterator::next a bit.

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