style: Remove ComputedStyle::mBits.
style: Remove ComputedStyle::mBits.

Use the Servo flags instead.

Differential Revision: https://phabricator.services.mozilla.com/D20729

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