OK, due to chrome making the change listed here recently
WebRTC can only work if the primary page is loaded over HTTPS, but you have to allow the browser to load the "unsecure" scripts to use WS since WSS is not supported. So, in Chrome as of version 47.0.2526.106, WebRTC with FreePBX 13 will only work in UCP if UCP is loaded via HTTPS and you force chrome to load the "unsafe" scripts using the shield icon on the right side of the URL. This worked for me. As of today, WebRTC is working with FPBX 13 on both Asterisk 11.20 and Asterisk 13.6