CenterOn = function (gameObject, x, y)
{
    SetCenterX(gameObject, x);

    return SetCenterY(gameObject, y);
}
Positions the Game Object so that it is centered on the given coordinates.

@function Phaser.Display.Bounds.CenterOn
@since 3.0.0

@generic {Phaser.GameObjects.GameObject} G - [gameObject,$return]

@param {Phaser.GameObjects.GameObject} gameObject - The Game Object that will be re-positioned.
@param {number} x - The horizontal coordinate to position the Game Object on.
@param {number} y - The vertical coordinate to position the Game Object on.

@return {Phaser.GameObjects.GameObject} The Game Object that was positioned.