Chavez by UD. Although, Floyd did fight a little more bravely at 130. If he fights more aggressively, than I would go with Chavez by late stoppage. Floyd has never been hit to the body as hard and as often as JCC would hit him.
Although Floyd was a crisp puncher at 130, he does not have anywhere near enough firepower to deter Julio's attack. Chavez would outwork and outfight Floyd.