[webcomponents] :unresolved vs :not(:upgraded) (#418)

It seems odd that the custom elements API and spec refers to upgrading custom elements and yet the CSS pseudo class that corresponds to a custom element not being upgraded is called `:unresolved`.  `unresolved` doesn't tell what hasn't been resolved and inconsistent with the rest of the spec / API terminology we're using.

Perhaps we should consider negating it to `:upgraded` and use `:not(:upgraded)` for this use case for consistency.  I do admit the the latter form is a bit more verbose but I think consistency in the terminology is very valuable here.

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/webcomponents/issues/418