Per CSSOM (and our implementation), a CSSStyleSheet's parent rule can only ever be a CSSImportRule. We should enforce this at compile time instead of allowing any CSSRule as parent.
Created attachment 117722 [details]
Comment on attachment 117722 [details]
Attachment 117722 [details] did not pass chromium-ews (chromium-xvfb):
Created attachment 117778 [details]
Patch for landing
Same patch with CodeGeneratorV8.pm tweaked to include CSSImportRule.h for CSSStyleSheet and StyleSheet bindings.
Committed r101943: <http://trac.webkit.org/changeset/101943>