Reviewed by Tim Hatcher.

    Reviewed by Tim Hatcher.

        Bug 16535: Stylesheets loaded with @import are not editable
        http://bugs.webkit.org/show_bug.cgi?id=16535
        <rdar://problem/5712899>

        Sheets loaded using @import were incorrectly being flagged as non-editable
        user agent sheets because their parent sheet doesn't have an ownerNode. We now
        check to make sure sheets also don't have a href before restricting their editability.

        * page/inspector/StylesSidebarPane.js:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@30654 268f45cc-cd09-0410-ab3c-d52691b4dbfc