[e] (0) Fix an example that would never have received its messages.

git-svn-id: http://svn.whatwg.org/webapps@4161 340c8d12-0b0e-0410-8428-c7bf67bfef74

complete.html

@@ -63163,6 +63163,8 @@ <h5 id=shared-workers><span class=secno>9.1.2.4 </span>Shared workers</h5>
      li.appendChild(form);
    }
    worker.port.addEventListener('message', startPrivateChat, false);
+
+   worker.port.start();
   &lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;