Track ancestorOrigins privacy issues

[jungkees]

f71dbb1 addressed the change in HTML that restored ancestor origins list.

There are ongoing discussion about privacy issues of location.ancestorOrigins. Related links:

• redact location.ancestorOrigins according to Referrer Policy whatwg/html#1918
• Meta: add ancestorOrigins warning due to continued disagreement whatwg/html#2251

[wanderview]

Should implementations wait to remove frameType until this is decided?

[jungkees]

It seems @annevk's working on it as commented in whatwg/html#1918 (comment).

the first time you hit no-referrer you append "null" and then return the list.

windowClient.ancestorOrigins just creates a frozen array from the ancestor origins list so won't need any change. I'd like to check though whether the privacy concern has been resolved.

[annevk]

I think you can probably use the ancestor origins list, yes, but my initial solution wasn't accurate, so let's wait a bit until I've figured out what HTML should say. I was hoping to get to it next week (tomorrow, really), but a couple other things came up so it might be delayed a little more.

[annevk]

There's a PR for HTML that addresses the privacy issue: whatwg/html#2480. There's also tests. However, thus far nobody has implemented that model yet.