Re-sync html/dom/interfaces.html web-platform-test from upstream.
Created attachment 286482 [details] Patch
Comment on attachment 286482 [details] Patch Clearing flags on attachment: 286482 Committed r204662: <http://trac.webkit.org/changeset/204662>
All reviewed patches have been landed. Closing bug.
Something is wrong with the updated test, it fails on EWS: <https://webkit-queues.webkit.org/results/1902939>
Re-opened since this is blocked by bug 161025
Fix attempted in https://trac.webkit.org/r204674