Let's conclude that chicken was first for a moment, and evolved from other kind of bird, so pushing this question even further - first bird on earth ever evolved from some other species, and was it able to lay the eggs, or evolved to it by the time? Or maybe first bird on earth ever was born from super egg came from other universe, who knows? It's very hard to answer this question, and in my opinion you can't answer it with full certanity because we are talking about things that happened too long ago to be certain of anything.