It's been enabled in cocoa for a long time.
Created attachment 306675 [details] Patch
Committed r215177: <http://trac.webkit.org/changeset/215177>
Why only Cocoa and GTK. Why would other ports not want this?
(In reply to Michael Catanzaro from comment #3) > Why only Cocoa and GTK. Why would other ports not want this? Actually there aren't other ports in wk2