<rdar://problem/58116514>
Created attachment 395475 [details] proposed patch.
Created attachment 395476 [details] proposed patch.
Comment on attachment 395476 [details] proposed patch. r=me.
Created attachment 395477 [details] patch for landing. Thanks for the review.
Created attachment 395486 [details] patch for landing.
Created attachment 395488 [details] patch for landing.
Landed in r259547: <http://trac.webkit.org/r259547>.