Free-agent guard Nick Young has agreed to a one-year, $5.2 million contract with the Warriors, a source has confirmed with The Chronicle. Though not known as much of a passer, Young is a quality three-point shooter who impressed Lakers head coach Luke Walton — a Steve Kerr protege — with his defense last season. Young has averaged 12 points on 41.9 percent shooting, including 37.6 percent from beyond the arc, over a 10-year career that has spanned stops with the Wizards, Clippers, 76ers and Lakers. In his first and only season under Walton, he enjoyed a bounce-back campaign, averaging 13.2 points and shooting 40.4 percent from three-point range in 60 games (all starts).