I didn't see this covered by the other patches working on this now. An unrelated patch I ran through EWS shuffled the unified builds such that this using statement caused build failures, and I came up with the fix.
Created attachment 357290 [details]
Comment on attachment 357290 [details]
Clearing flags on attachment: 357290
Committed r239218: <https://trac.webkit.org/changeset/239218>
All reviewed patches have been landed. Closing bug.