static normalizeEventInfo(event) {
    let touchEvent = {pageX: 0, pageY: 0};

    if (typeof event.changedTouches !== 'undefined') {
      touchEvent = event.changedTouches[0];
    } else if (typeof event.originalEvent !== 'undefined' &&
        typeof event.originalEvent.changedTouches !== 'undefined') {
      touchEvent = event.originalEvent.changedTouches[0];
    }

    const x = event.offsetX || event.layerX || touchEvent.pageX;
    const y = event.offsetY || event.layerY || touchEvent.pageY;

    return {x, y};
  }
Normalizes an event to deal with differences between PointerEvent and
TouchEvent.
@param {Event} event
@return {Object} Normalised touch points.