This code was added in r258120, and can be removed, since it is currently not in use.
Created attachment 396306 [details] Patch
Created attachment 396309 [details] Patch
Committed r260034: <https://trac.webkit.org/changeset/260034> All reviewed patches have been landed. Closing bug and clearing flags on attachment 396309 [details].
<rdar://problem/61731451>