This can be done by eliminating the old properties (like we did with -webkit-opacity), since there are no syntactic incompatibilities.
(In reply to comment #0) > This can be done by eliminating the old properties (like we did with > -webkit-opacity), since there are no syntactic incompatibilities. I think there is an incompatibility: -webkit-border-radius: 10px 20px; means 10-by-20 ellipse in every corner. border-radius: 10px 20px; means 10-by-10 circles in the top left and bottom right corners, 20-by-20 in the other corners.
I made a single patch for this bug and for bug 27584 and attached it to that bug.
Fixed in <http://trac.webkit.org/changeset/46508>.