- fix <rdar://problem/5206089> REGRESSION: hovering over amazon.com "product categories"
          tab makes page content disappear

        The contentWindow property was doing a cross-frame security check, but it shouldn't.
        Window objects are responsible for protecting themselves from cross-frame activity.
        Because contentWindow returned undefined, we then ended up setting visibility on the
        body of the main frame to "hidden".

        No layout test yet. When we make cross-domain tests, we should include this one.

        * html/HTMLFrameElement.idl: Removed CheckFrameSecurity attribute from contentWindow.
        * html/HTMLIFrameElement.idl: Ditto.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@21646 268f45cc-cd09-0410-ab3c-d52691b4dbfc