[css-conditional][quirks] Quirks mode and @supports/CSS.supports

[svgeesus]

from https://lists.w3.org/Archives/Public/www-style/2015Nov/0338.html by @zcorpan

What is the interaction between

https://drafts.csswg.org/css-conditional/#at-supports
https://drafts.csswg.org/css-conditional/#the-css-interface

...and...

https://quirks.spec.whatwg.org/#the-hashless-hex-color-quirk
https://quirks.spec.whatwg.org/#the-unitless-length-quirk

Testing in
http://software.hixie.ch/utilities/js/live-dom-viewer/saved/3765 it
appears that in Blink/WebKit/Gecko apply the quirks in @supports, but not
in CSS.supports(). Presto doesn't apply the quirks to @supports and
doesn't have CSS.supports(). I haven't checked IE/Edge. I suggest we
specify what Blink/WebKit/Gecko do.

[zcorpan]

This has been specified and tested by now, so I think we can close this.

[svgeesus]

Thanks @zcorpan was the fix in css-conditional or in quirks?

[zcorpan]

Quirks.