title: webRTC createDataChannel throws a DOM exception in Chrome Canary
body: <p>I'm trying to create a data channel in the latest Chrome Canary (dataChannel flag is on).</p>
  
  <pre><code>var SERVER = "stun:stun.l.google.com:19302";  
  var pc1 = new window.webkitRTCPeerConnection({"iceServers": [{"url": SERVER}]});
  pc1.createDataChannel('my_channel');
  </code></pre>
  
  <p>Canary throws me the following exception : NotSupportedError: DOM Exception 9</p>
  
  <p>Does anybody know why is that happening?</p>