To what agreement did Pony and Darry come?

Soda confesses how upset it makes him when Darry and Ponyboy fight. He says that all they have is each other, and that they need to stick together in order not to end up the way Dally was before he died, hardened. Darry and Ponyboy agree not to fight anymore, suddenly realizing how much they accidentally have been hurting Soda.