CocoonJS does not support many features that the entire C2 relies on. CJS does support a lot of the core game elements. Unfortunatly WebRTC and advanced WebAudio are not in that list. Though CJS does support audio their own audio system to at least have good sound to an extent.
The best way to get WebRTC is to find the closest to the WebRTC api standard. there are a few, but I think this one might be the closest.
Create a plugin that shims( https://en.wikipedia.org/wiki/Shim_(computing) ) C2 use of the webrtc of a browser, to the cordova plugin. The shim puts all the missing functions and references and makes links to the cordova plugin. If the plugin and shim supports all the same functions as what C2 uses. Then you should have WebRTC on IOS.