Chrome for iOS is using WKWebView’s loadSimulatedRequest API to display error pages for failed navigations. One reason for a navigation failing is when a URL is blocked by enterprise policy. In this case, Chrome tries to load a simulated request with an error message, using the URL of the blocked page. However, in decidePolicyForNavigationAction, the URL blocking logic cannot distinguish a real load of the blocked page vs a simulated request using that URL, since there's no information in the WKNavigationAction to tell us that this is a simulated request. One way to fix this would be to promote the _mainFrameNavigation SPI in WKNavigationAction to API, so that we can compare that WKNavigation* to the one returned by loadSimulatedRequest. I've also filed FB9974496 for this request.
rdar://91316525