OWINGS MILLS, Md. — Baltimore Ravens defensive tackle Haloti Ngata said he tried to be a dispassionate observer of the divisional playoff game between the New England Patriots and the Houston Texans. As he watched the game on television, Ngata studied both offenses, at least until the third quarter, when it became clear that the Patriots were well on their way to securing a rematch with the Ravens in Sunday’s A.F.C. Championship game.