fn parse_attribute_value(
name: &Atom,
attribute_data: &AttributeData,
url_data: &UrlExtraData,
attribute_tracker: &mut AttributeTracker<'_>,
) -> Result<ComputedValue, ()>Expand description
Attribute values may reference other substitution functions we may need to process. See step 6: https://drafts.csswg.org/css-values-5/#attr-substitution