[cssom] Element.getComputedStyle()

[hfhchan]

Suggest introducing Element.getComputedStyle( [pseudoelt] ) and Element.getUsedStyle( [pseudoelt] ) with proper computed value and used value semantics.

window.getComputedStyle( element, [pseudoelt] ) looks like a procedural function attached on a random object.

[dbaron]

I think the draft had something like this for a while, but it was removed since nobody implemented it. (Although I was mildly interested, but just hadn't gotten to it.)