Preheat oven to 350° F.
To prepare barbecue rub, in small bowl, combine chili, onion and garlic powders and paprika; rub evenly over both sides of chicken breasts.
Place chicken onto large sheet of foil; wrap chicken in foil, crimping edges to seal. Place foil packet onto baking sheet; bake 8 minutes. Carefully open foil packet; bake 4 minutes, until chicken is cooked through and juices run clear when pierced with fork. Set aside to cool.
Meanwhile, place lettuce into large bowl; top with tomatoes, corn and onion. With fork, shred cooled chicken; add to lettuce mixture. Drizzle evenly with dressing.
Servings: 4. Serving size: (2) 1/2 cups