Those declarations are crumbs left from https://bugs.webkit.org/show_bug.cgi?id=161605
Created attachment 390391 [details] Patch
I always forget to flip the commit-queue flag :S
Comment on attachment 390391 [details] Patch Clearing flags on attachment: 390391 Committed r256428: <https://trac.webkit.org/changeset/256428>
All reviewed patches have been landed. Closing bug.