Same test isn't failing on macOS.
Test was just added in r227068.
Created attachment 331535 [details] Patch
Comment on attachment 331535 [details] Patch Clearing flags on attachment: 331535 Committed r227084: <https://trac.webkit.org/changeset/227084>
All reviewed patches have been landed. Closing bug.
<rdar://problem/36595979>