Third-party extensions using WKWebView are unable to render anything because we do not get notified when the extension's visibility changes. Because we do not recognize the extension showing the WebView to be foreground, we do not take a process assertion on behalf of the child processes and they get suspended before they get a chance to render anything.
<rdar://problem/51105015>
Created attachment 370908 [details] Patch
Comment on attachment 370908 [details] Patch r=me
r=me
Created attachment 370954 [details] Patch
The commit-queue encountered the following flaky tests while processing attachment 370954 [details]: fetch/fetch-worker-crash.html bug 187257 (author: youennf@gmail.com) The commit-queue is continuing to process your patch.
Comment on attachment 370954 [details] Patch Clearing flags on attachment: 370954 Committed r245896: <https://trac.webkit.org/changeset/245896>
All reviewed patches have been landed. Closing bug.