Style::Scope doesn't need to be aware of XSLT at all. Remove the code once the patch for https://webkit.org/b/178715 is landed.
This is still present here: https://github.com/WebKit/WebKit/blob/a39b520b8e0ca63489db7a45fe19181a33fac903/Source/WebCore/style/StyleScope.cpp#L329 Also dependent bug is also fixed now. Just wanted to update latest status. Thanks!
<rdar://problem/97759985>