OAK BLUFFS, Massachusetts — A man who as a child had a brief but key role in “Jaws” has been named police chief on the Massachusetts island on which the 1975 movie was partially filmed. Jonathan Searle was offered the job of police chief in Oak Bluffs on Martha’s Vineyard last week. “I’m clearly elated and and I’m humbled and honored to have been offered the position,” Searle, currently a sergeant with Edgartown police, told the Vineyard Gazette, which first reported the appointment. The movie centers on the efforts of a police chief in a fictional resort town trying to rid the local waters of a killer shark.