We presently don't fire error events if CSP blocks loading of inline stylesheets or style elements.
<rdar://problem/101308540>
Pull request: https://github.com/WebKit/WebKit/pull/5512
Committed 255744@main (d487138f2ba5): <https://commits.webkit.org/255744@main> Reviewed commits have been landed. Closing PR #5512 and removing active labels.