Reviewed by Tor Arne.

        Fix handling of mouse events when embedding QWebView into the
        QGraphicsView.

        QWebPage accepts or ignores events to indicate whether the web page
        handled the event. However for QWebView to behave like a good widget
        it should always accept the mouse events to indicate that it handled
        them and that they should not be subject to event propagation.

        The graphics view relies on acceptance of the initial mouse click to
        make the embedded widget the focus item.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@37809 268f45cc-cd09-0410-ab3c-d52691b4dbfc