title: navigator.onLine still true when turning off WiFi, false when set "work offline" in browser
body: <p>navigator.onLine is still returning true when I turn off Wi-Fi (Airport on my notebook in OS X).  This is counterintuitive behavior.  But when I set "work offline" in a browser like Firefox, it correctly returns false.  Is this expected?</p>
  
  <pre><code>alert(navigator.onLine ? "online" : "offline");
  </code></pre>