Resync web-platform-tests/interfaces tests from upstream.
Created attachment 412770 [details] WIP Patch
Created attachment 412776 [details] Patch
Created attachment 412790 [details] Patch
Comment on attachment 412790 [details] Patch rs=me
Committed r269214: <https://trac.webkit.org/changeset/269214> All reviewed patches have been landed. Closing bug and clearing flags on attachment 412790 [details].
<rdar://problem/70904141>