title: How to use getUserMedia with geckofx
body: <p>How does one enable webrtc with <a href="https://bitbucket.org/geckofx" rel="nofollow">geckofx</a>?</p>
  
  <p>I've tried</p>
  
  <pre><code>        var perm = Xpcom.CreateInstance&lt;nsIPermissionManager&gt;("@mozilla.org/permissionmanager;1");
          nsIURI pwcom = Xpcom.CreateInstance&lt;nsIIOService&gt;("@mozilla.org/network/io-service;1").NewURI(new nsAUTF8String("https://apprtc.appspot.com"), null, null);
          perm.Add(pwcom, "camera", 1, 0, 0);
          perm.Add(pwcom, "video-capture", 1, 0, 0);
          perm.Add(pwcom, "audio-capture", 1, 0, 0);
  </code></pre>
  
  <p>To give permission to site to use getUserMedia, but still can't use any webrtc demo sites (such as <a href="https://apprtc.appspot.com" rel="nofollow">https://apprtc.appspot.com</a>)</p>
  
  <p>I'm using GeckoFX 29.0.10</p>
  
  <p>PS I've included an nsIConsoleListener which only emits</p>
  
  <p>2014-11-10 214218 consoleListener.Observe: [JavaScript Error: "TypeError: window.arguments is undefined" {file: "chrome://global/content/alerts/alert.js" line: 42}]</p>
  
  <p>2014-11-10 214219 consoleListener.Observe: [JavaScript Error: "NS_ERROR_NOT_IMPLEMENTED: " {file: "chrome://global/content/alerts/alert.js" line: 77}]</p>
  
  <p>Is the alert.js used for the prompt requesting which device to use for webrtc?</p>