Naming this effort

[domenic]

See whatwg/html#4872 (comment) for why "origin isolation" may or may not be the best name.

[annevk]

Bikeshed: immutable origin. (As origin being mutable in realms in window agents is the reason we're in this mess, I realized twice more today.)

[domenic]

I like that...

It's perhaps less obvious to web developers that making your origin immutable causes the scope of memory-sharing to change to same-origin instead of same-site. But it makes sense once you explain it. And maybe if we pull off whatwg/html#4920 then we don't even need to explain it.

[domenic]

Especially as of fabdc7c, I've come to accept origin isolation. So, I'll close this for now.