CONSOLE MESSAGE: line 26: [blocked] The page at https://127.0.0.1:8443/security/mixedContent/resources/insecure-xhr-sync-in-main-frame-window.html was not allowed to run insecure content from http://127.0.0.1:8000/xmlhttprequest/resources/access-control-basic-allow-star.cgi.

This test opens a HTTPS window that loads insecure data via synchronous XHR. We should trigger a mixed content callback because the main frame in the window is HTTPS but now has insecure data.