[css-animations] Consider accepting string as animation name

[upsuper]

WebKit's implementation supports using a string after @keyframes and animation-name. Blink supports this syntax for prefixed stuffs but not for unprefixed ones.

We've seen a website depends on this syntax (webcompat/web-bugs#2337). Not sure how widely this kind of thing is used, but in general, I guess it is not a bad idea to accept string as animation name.

I raised this for the compat spec (whatwg/compat#43) but it'd probably better to be discussed in CSSWG.

[tabatkins]

I'm fine with allowing this. Ignoring compat, it lets authors provide animation names without risk of them being misparsed for accidentally coinciding with one of the other animation keywords.

[birtles]

I started working on the edits for this but I'm wondering, is this sufficient?
https://github.com/w3c/csswg-drafts/compare/birtles/allow-strings-for-animation-name

[upsuper]

It seems there is a grammar in section 4 just before 4.1, which is not updated.

[upsuper]

And I think it would also be good to make it clear whether there is any difference between rules defined with a string name and those with an identifier name.

I guess (but not verified carefully) that current implementations which support it would treat ident and "ident" identically. If so, we should probably write that into the spec explicitly.

[tabatkins]

We resolved in the telcon to accept this.