Auto merge of #7920 - glennw:flaky-snap, r=mbrubeck
Auto merge of #7920 - glennw:flaky-snap, r=mbrubeck

Workaround for #7730.



<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/7920)
<!-- Reviewable:end -->

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