Re: [csswg-drafts] [css-conditional-3] [css-fonts-4] Allow CSS.supports('font-family: system-ui') for feature detection

Spec-wise, `CSS.supports` defines:
> value would be successfully parsed as a supported value for that 
property

and `system-ui` is a valid 
[font_family_name](https://drafts.csswg.org/css-fonts-3/#fontfamilyname),
 so it should return true.

A function syntax as suggested by @upsuper might work, but probably 
the first thing to discuss is what are the cases where cascading 
[font_family_name_list](https://drafts.csswg.org/css-fonts-3/#fontfamilynamelist)
 cannot solve but `CSS.supports` can. Do you have any examples in 
mind?

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Received on Tuesday, 11 October 2016 14:20:18 UTC