title: sessionStorage not cleaned when browser hangged
body: <p>I have build an application wherein i am saving the token received from server into sessionStorage on client side. The session expiry time is 30mnts. The application works well in given scenario:</p>
  
  <p>Working correctly</p>
  
  <ol>
  <li>User opens the application.</li>
  <li>Idle for 30 minutes and then click on any links</li>
  <li>Session expiry message appears fine.</li>
  <li>User close the window and launches a new window, application laods successfully</li>
  </ol>
  
  <p>However the below scenario doesn't work properly consider a new sessionStorage allocated to a new window (Incorrect behavior):</p>
  
  <ol>
  <li>User opens the application.</li>
  <li>Idle for 5-6 hours or maybe overnight</li>
  <li>User comes back next day and tries to click on stale session</li>
  <li>Browser hangs up and not responding</li>
  <li>User close the window and launches a new window, application displays session timeout page. User has to refresh or relaunch the page.</li>
  </ol>