I don't see any definition nor call for it. Also discovered while investigating bug 172753 (you can't misgrep fast enough).
Created attachment 314595 [details] Patch
Comment on attachment 314595 [details] Patch Clearing flags on attachment: 314595 Committed r219130: <http://trac.webkit.org/changeset/219130>
All reviewed patches have been landed. Closing bug.