Window name targeting: checking "allowed by sandboxing to navigate" is not interoperable

[domenic]

What is the issue with the HTML Standard?

After #10818 merges, we will have two implementation-defined steps in "find a navigable by target name" which check "allowed by sandboxing to navigate".

@kjmcnee states:

Firefox and Chromium do this. WebKit does not.

Firefox and Chromium's behavior here seems significantly better. We should standardize on it.

The only hard part will be writing appropriate web platform tests. For inspiration on how to write such tests, you can see Kevin's web-platform-tests/wpt#49631 . We just need to establish a setup where the two strategies give different results and then assert the Firefox/Chromium behavior.