CLEVELAND — Over the past eight months, as they toiled through frequent lapses in focus and urgency, the Warriors repeated three words: "We'll be fine." Though the talent divide separating it from the rest of the league has tightened, Golden State has long known that its biggest opponent is itself. In its 108-85 win over the Cavaliers in Game 4 of the NBA Finals on Friday night at Quicken Loans Arena, the Warriors finally put it all together for four quarters, riding the same joy that made them the class of the league to their second straight championship and their third in four years.