 for adding cross-platform gesture event listeners.
   */
  const Gestures = {
    gestures: {},
    recognizers: [],

    /**
     * Finds the element rendered on the screen at the provided coordinates.
     *
     * Similar to `document.elementFromPoint`, but pierces through
     * shadow roots.
     *
     * @memberof Polymer.Gestures
     * @param {number} x Horizontal pixel coordinate
     * @param {number} y Vertical pixel coordinate
     * @return {HTMLElement} Returns the deepest shadowRoot inclusiv