SANTA CLARA — You could say the 49ers owed the New England Patriots one after the Jimmy Garoppolo gift that revitalized their franchise last season. So, after giving up Garoppolo for only a second-round draft pick, the Patriots called in a favor Friday to acquire offensive tackle Trent Brown in a trade, a league source confirmed. Brown, a two-year starter at right tackle, became expendable in expedited fashion once the 49ers drafted his replacement, Mike McGlinchey, at No. 9 overall in Thursday’s first round. The 49ers, according to ESPN, acquired a third-round draft pick from the Patriots (No. 95 overall) in exchange for Brown and a fifth-round pick (No. 143, which the 49ers acquired in last