[css-paint-api][css-typed-om] Reifying inputArguments

[andruud]

CSS Typed OM does not define how to reify values without the context of a property. This means that we can't create a CSSStyleValue from a syntax descriptor: we'd need a property registered with that syntax. (For instance, if you pass a <color> as an input argument, what is the [[associatedProperty]] set to for the resulting direct CSSStyleValue? An easy thing to fix maybe, but it's not defined currently).

We could say that these values are reified in the context an anonymous registered custom property with that syntax ... or something.

cc @bfgeek

[tabatkins]

Oooh, good catch.

Yes, I agree that reifying in the context of a registered custom property is the right way to go. You can't rely on the containing property; once custom functions exist, width: --foo(50%); does not necessarily tie the % resolution to how width: 50%; works.