The fix for bug 37878 had too many side effects on Mac. I'll #ifdef this out for Mac until we sort them out.
Created attachment 54207 [details]
Comment on attachment 54207 [details]
Should there be a bug for re-enabling this?
Landed in <http://trac.webkit.org/projects/webkit/changeset/58222>.
http://trac.webkit.org/changeset/58222 might have broken SnowLeopard Intel Release (Tests)
Thanks for landing this, Mitz!