LOS ANGELES — The Boston Bruins figured their road swing against the NHL’s three tough California teams would be a strong indication of their ability to contend for a playoff spot. Interim coach Bruce Cassidy thinks the Bruins are leaving the Golden State in great shape. Brad Marchand and David Pastrnak scored their 26th goals of the season, and the Bruins improved to 5-1-0 under Cassidy with a 4-1 victory over the Los Angeles Kings on Thursday night. Anton Khudobin made 27 saves in his second start since Christmas for the Bruins, who nursed an early lead to their first win in Los Angeles since March 24, 2012.