getPropertyType and SVGScriptElement href baseVal property

[lukewarlow]

Currently getPropertyType's spec and both Chromium and WebKit's implementation has no handling of the .href.baseVal property of an SVGScriptElement, but it does require a TrustedScriptURL.

cc @koto what should we do here?

[koto]

Realistically we only have two choices, either ignore it (as baseVal is a property of SVGAnimatedString and not an element), or use a meta syntax like href.baseVal for the property name and add an entry for it in getPropertyType.

I have a slight preference to the former - getPropertyType does not cover all TT sinks, and we should just assume that SVG animations are another vector that needs to be handled separately.

[lukewarlow]

Yeah I have a preference for ignoring it too. Same way lots of functions require a trusted type without a metadata API.

[fred-wang]

cc @smaug----