title: WebRTC: Why "CreateAnswer can't be called before SetRemoteDescription"?
body: <p>Browser: Chrome</p>
  
  <p>I am trying to debug a webRTC application which works fine on three out of four fronts! I cannot get video from the receiver to the caller. I can get video and audio from the caller to the receiver and audio from the receiver to the caller. The problem is that the receiver does not fire a video (sdpMid="video") ICE candidate. While desperately trying to solve this problem, I tried to use pc.CreateAnswer before setting pc.remoteDescription and it gave the error quoted in the title.</p>
  
  <p>My question is to understand the reason behind this. An answer SDP would just be the SDP based upon the getUserMedia settings/constraints. So, why do we have to wait for setting remoteDescription. I thought that a createAnswer would start firing the gathering of ICE candidates and this can be done earlier without waiting to set remoteDescription. That is not the case. Why?</p>