I over-engineered this somewhat.
Created attachment 156679 [details] Patch
Created attachment 156687 [details] Patch
Comment on attachment 156687 [details] Patch r=me
Comment on attachment 156687 [details] Patch Clearing flags on attachment: 156687 Committed r124779: <http://trac.webkit.org/changeset/124779>
All reviewed patches have been landed. Closing bug.