Preheat oven to 350. Prepare a 9" x 13" pan with cooking spray; set aside. In a large skillet, cook chicken, onions, and chilies, until the chicken is no longer pink. Add refried beans,12 ounces of the salsa, and salt. Mix well and cook over low heat. Spoon 1/4 cup of the chicken mixture onto each tortilla. Fold one edge of each tortilla over the filling; this keeps the filling from spilling out. Roll up burritos and place seam-side-down in the prepared pan; set aside. In a small bowl, combine the remaining salsa and diced tomatoes. Mix well. Spread evenly over top burritos and sprinkle cheese evenly over top. Bake for 30 minutes or until heated through.