Combine the salsa, olive oil and lime juice; set aside.
Season the chicken.
Light the grill to medium heat. Remove any tired outer leaves from the romaine, then halve each head vertically. Place on a large platter and spray cut sides with olive oil spray. Lightly spray corn with olive oil.
Place chicken and corn on the grill and cook, until cooked through, about 5 minutes on each side, until the chicken is cooked through and the corn is tender. Remove and place on a cutting board.
Grill romaine close to the heat source over high, cut side down about 1 to 2 minutes. Remove.
Slice the chicken into strips, cut the kernels off the corn and serve over Romaine with avocado, tomatoes, onions, salt and dressing on top.