This is not intended to work right now. Opt out so that we don't crash.
Created attachment 340198 [details] Proposed fix
<rdar://problem/40185508>
Comment on attachment 340198 [details] Proposed fix Clearing flags on attachment: 340198 Committed r232133: <https://trac.webkit.org/changeset/232133>
All reviewed patches have been landed. Closing bug.