Supporting svg fill-rule. Renaming the Comment to SVGComment.

How is this different? If you haven't found anything by going through the full tree, then ... how would looking at the root make a difference?

Off the top of my head, I don't know why we refuse to accept styles defined on "SVGSVGElement" (which will be the exact same as self.rootOfCurrentDocumentFragment) - is this in the spec, maybe?