In a mixing bowl, beat cream cheese and 1/3 cup sugar until light and fluffy. Beat in 1 egg; set aside. In a saucepan, bring water, butter and chocolate to a boil, stirring occasionally. Remove from the heat. Mix in flour and remaining sugar. Stir in sour cream, baking soda, salt and remaining eggs until smooth. Pour into a greased and floured 15 inch x 10 inch x 1 inch baking pan. Dollop cream cheese mixture over the top; cut through batter to create a marble effect. Sprinkle with chocolate chips. Bake at 375 °F for 30 to 35 minutes or until a toothpick inserted near the center comes out clean. Cool.