This seems to have started after https://trac.webkit.org/changeset/261506/webkit landed.
<rdar://problem/63452877>
Created attachment 399914 [details] Patch
Comment on attachment 399914 [details] Patch r=me
(In reply to Maciej Stachowiak from comment #3) > Comment on attachment 399914 [details] > Patch > > r=me Thanks!
Committed r262006: <https://trac.webkit.org/changeset/262006> All reviewed patches have been landed. Closing bug and clearing flags on attachment 399914 [details].