style: Fix serialization of explicitly case-sensitive attr selectors with a namespace.
style: Fix serialization of explicitly case-sensitive attr selectors with a namespace.

Differential Revision: https://phabricator.services.mozilla.com/D14493

pyfisch/servo,emilio/servo,KiChjang/servo,nnethercote/servo,paulrouget/servo,paulrouget/servo,DominoTree/servo,splav/servo,splav/servo,KiChjang/servo,splav/servo,paulrouget/servo,pyfisch/servo,emilio/servo,peterjoel/servo,pyfisch/servo,pyfisch/servo,notriddle/servo,pyfisch/servo,szeged/servo,notriddle/servo,szeged/servo,paulrouget/servo,nnethercote/servo,emilio/servo,nnethercote/servo,saneyuki/servo,emilio/servo,splav/servo,notriddle/servo,peterjoel/servo,DominoTree/servo,nnethercote/servo,peterjoel/servo,paulrouget/servo,DominoTree/servo,splav/servo,saneyuki/servo,emilio/servo,KiChjang/servo,szeged/servo,larsbergstrom/servo,saneyuki/servo,saneyuki/servo,splav/servo,splav/servo,nnethercote/servo,larsbergstrom/servo,KiChjang/servo,saneyuki/servo,szeged/servo,larsbergstrom/servo,KiChjang/servo,DominoTree/servo,KiChjang/servo,saneyuki/servo,emilio/servo,peterjoel/servo,notriddle/servo,paulrouget/servo,szeged/servo,larsbergstrom/servo,DominoTree/servo,emilio/servo,peterjoel/servo,szeged/servo,nnethercote/servo,KiChjang/servo,notriddle/servo,pyfisch/servo,nnethercote/servo,emilio/servo,DominoTree/servo,notriddle/servo,larsbergstrom/servo,szeged/servo,peterjoel/servo,KiChjang/servo,peterjoel/servo,larsbergstrom/servo,KiChjang/servo,saneyuki/servo,peterjoel/servo,splav/servo,nnethercote/servo,larsbergstrom/servo,DominoTree/servo,nnethercote/servo,szeged/servo,pyfisch/servo,szeged/servo,pyfisch/servo,splav/servo,emilio/servo,peterjoel/servo,notriddle/servo,DominoTree/servo,KiChjang/servo,peterjoel/servo,larsbergstrom/servo,splav/servo,larsbergstrom/servo,larsbergstrom/servo,notriddle/servo,nnethercote/servo,szeged/servo,notriddle/servo,DominoTree/servo,paulrouget/servo,pyfisch/servo,paulrouget/servo,emilio/servo,pyfisch/servo,paulrouget/servo,saneyuki/servo,saneyuki/servo,paulrouget/servo,DominoTree/servo,notriddle/servo,saneyuki/servo