Accept-CH cache is not updated on redirects

[davidben]

If, on a top-level navigation, we get a redirect, I believe the spec currently will not pick up Accept-CH on those rounds, since that happens at create and initialize a Document object. (See https://wicg.github.io/client-hints-infrastructure/#document-init and https://wicg.github.io/client-hints-infrastructure/#abstract-opdef-initialize-the-client-hints-set.)

Probably it should happen earlier, maybe in process a navigate fetch?

[arichiv]

I'm closing this as intentional, it seems like an abuse of the system to allow redirects to update the Accept-CH cache (instead of using a Critical-CH header). @yoavweiss in case I'm wrong

[davidben]

Not sure I follow. Critical-CH depends on the Accept-CH cache in the first place, and there are normal reasons to send redirects. (And, IIRC, our implementation does process Accept-CH on redirect. The problem is the spec doesn't match.)

[arichiv]

I was about to follow up that I was wrong, will fix in #42 (since that fix seems to overlap with the need here). Sorry about that