title: WebRTC: Renegotiation in firefox
body: <p>According to <a href="https://hacks.mozilla.org/2015/03/webrtc-in-firefox-38-multistream-and-renegotiation/">this article</a>, re-negotiation is implemented in firefox v38 and we can add remove streams from same peerconnections without creating new ones, but I am unable to find any working demos to support that claim, and when I tried it, two users chating in video mode, I changing one of their stream to <code>audio</code>, I get the error:</p>
  
  <blockquote>
    <p>NotSupportedError: removeStream not yet implemented</p>
  </blockquote>
  
  <p><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=844295">this</a> tells the same, but <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=857115">this</a> tells renegotiation events are supported, but isn't <code>removeStream</code> key part of renegotiation? I am using firefox version 39 in windows 7. I am confused, renegotiation is not yet supported in firefox, right?</p>