I had it a draw, the only way it could have gone to Brooks is through scoring 5 for him, which I don't think he had enough of any edge earlier to overcome Chandler knocking him down and the submission attempt.
I don't get why Chandler chose to defend that way off his back though, really cost him in the third round. He needs to train his defense off his back, he was a bit sloppy all-around tonight.