In your Chassis class you have a RobotDrive that is using the same channels as the 4 Jaguars you created. What you want to do is pass those 4 Jaguars into the RobotDrive constructor, not pass in the channels again.
Code:
roborDrive = new RobotDrive(frontLeftMotor, rearLeftMotor, frontRightMotor, rearRightMotor);