title: How to use console.timeStamp in Chrome?
body: <p>I try to use <code>console.timeStamp</code> in firebug, it works:</p>
  
  <pre><code>console.timeStamp()
  12:16:26.188
  </code></pre>
  
  <p>but this does't work in chrome, it show <code>undefined</code></p>
  
  <p>how can I use it?</p>