Add default implementations of WebNotificationPresenter methods to
        repair the downstream Chromium build.

        * public/WebNotificationPresenter.h:
        (WebKit::WebNotificationPresenter::show):
        (WebKit::WebNotificationPresenter::cancel):
        (WebKit::WebNotificationPresenter::objectDestroyed):
        (WebKit::WebNotificationPresenter::checkPermission):
        (WebKit::WebNotificationPresenter::requestPermission):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@57046 268f45cc-cd09-0410-ab3c-d52691b4dbfc