title: When does RTCIceConnectionState.closed get fired
body: <p>From Mozilla <a href="https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection/iceConnectionState" rel="nofollow noreferrer">doc</a> it says</p>
  <blockquote>
  <p>&quot;closed&quot;: The ICE agent for this RTCPeerConnection has shut down and is
  no longer handling requests.</p>
  </blockquote>
  <p>When or how does a RTCPeerConnection gets <strong>shut down</strong></p>