NEW YORK — Raised in upstate New York, Chad Brown didn’t root for the Bills, the Giants or the Jets when it came to football. The 39-year-old from Mechanicville was a San Francisco 49ers fan. It was simple. He liked future Hall of Fame quarterback Joe Montana, although football didn’t turn out to be Brown’s sport. Brown has become one of thoroughbred racing’s top trainers, and his favorite football team now is the New England Patriots.