Fix #522 - Add optional extra events for some edge cases

For some rare situations where we need to make a decision based on a frame state that we don't have yet, we'll create the frame state based on the info in the webrequest event. In Chromium-based browsers, this is only the domain and not the full URL for the page.

This is rare in practice, but the code appears to be working as expected when it does happen. This MR updates the test to reflect these expectations.

Also fixes #530 (closed)