Southwestern Cheesy Corn Dip


1 cup fresh Roma tomatoes, cut into large pieces
1 ½ teaspoons kosher salt, divided
1 tablespoon vegetable oil
1 cup red onion diced
3 ears of corn shucked and removed from cob, or 3 cups frozen
1 medium jalapeno stemmed, seeded and diced
1 teaspoon paprika
1 teaspoon granulated sugar
8 ounces Monterey Jack cheese, shredded
1 pound Fontina cheese, shredded
8 ounce cream cheese
½ cup mayonnaise
Tortilla chips, for serving