URL set by document.open() is communicated with the WebPageProxy (since r244361) but not the WebFrameProxy.
<rdar://problem/49237544>
Created attachment 368069 [details] Patch
Comment on attachment 368069 [details] Patch I think I hit an assertion related to this.
Comment on attachment 368069 [details] Patch Clearing flags on attachment: 368069 Committed r244590: <https://trac.webkit.org/changeset/244590>
All reviewed patches have been landed. Closing bug.