Add function which convert from URLValueData to SpecifiedUrl.
Add function which convert from URLValueData to SpecifiedUrl.

We will need to convert from URLValueData to SpecifiedUrl when cloning the
stylo's data from gecko's data. Because the filter structure on gecko has url as
URLValue type. We will use this convert function when interpolating as
discrete also(Bug 1368610).

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