Enable it at runtime by default.
<rdar://problem/46046861>
Created attachment 354726 [details] Patch
Created attachment 354741 [details] Patch
Created attachment 354742 [details] Patch
Comment on attachment 354742 [details] Patch Clearing flags on attachment: 354742 Committed r238213: <https://trac.webkit.org/changeset/238213>
All reviewed patches have been landed. Closing bug.