function asTRBL(bounds) {
  return {
    top: bounds.y,
    right: bounds.x + (bounds.width || 0),
    bottom: bounds.y + (bounds.height || 0),
    left: bounds.x
  };
}
Convert the given bounds to a { top, left, bottom, right } descriptor.

@param {Point|Rect} bounds

@return {RectTRBL}