[cssom-1] `CSSStyleDeclaration.getPropertyPriority()` for resolved values

[cdoublev]

https://drafts.csswg.org/cssom-1/#dom-cssstyledeclaration-getpropertypriority

Should it return empty string when the computed flag is set, like in Chrome/FF (at least)?

<style>#target { color: red !important }</style>
<script>
  getComputedStyle(target).getPropertyPriority('color') // ''
</script>

[emilio]

I think this is how it should work per spec, because https://drafts.csswg.org/cssom-1/#dom-window-getcomputedstyle doesn't set the important flag anywhere:

decls to a list of all longhand properties that are supported CSS properties, in lexicographical order, with the value being the resolved value computed for obj using the style rules associated with doc. Additionally, append to decls all the custom properties whose computed value for obj is not the guaranteed-invalid value.

Let me know / reopen if that's somehow not your read as well, or if any further clarification is needed.

[cdoublev]

Sorry for not being explicit. Would you accept a PR adding this step?

1. If the computed flag is set, then return the empty string

[Loirooriol]

What would this solve? The current steps already produce empty string.

[cdoublev]

Nothing (I guess), I suggest it for consistency with getPropertyValue() and for the same reason as in #6144.