Preheat broiler. Line a 15x10x1-inch baking pan with foil; set aside. In a large bowl combine masa harina, the water, dried cranberries, garlic, oregano, and salt. Add ground pork and ground turkey; mix well. Shape into 1-inch meatballs. Place in the prepared baking pan. Broil 4 to 5 inches from the heat for 5 to 8 minutes or until lightly browned, turning once.
In a 3 1/2- or 4-quart slow cooker combine meatballs, broth, salsa, corn, and tortilla chips. Cover and cook on low-heat setting for 6 to 7 hours or on high-heat setting for 3 to 3 1/2 hours.
If using low-heat setting, turn to high heat setting. Stir in pasta. Cover and cook about 30 minutes more or until pasta is tender. Before serving, stir in 1/4 cup green onions. If desired, garnish each serving with additional green onions.