function ensureScrollValueMonitoring() {
	    if (hasEventPageXY === undefined) {
	      hasEventPageXY = document.createEvent && 'pageX' in document.createEvent('MouseEvent');
	    }
	    if (!hasEventPageXY && !isMonitoringScrollValue) {
	      var refresh = ViewportMetrics.refreshScrollValues;
	      ReactBrowserEventEmitter.ReactEventListener.monitorScrollValue(refresh);
	      isMonitoringScrollValue = true;
	    }
	  }
/**
	   * Listens to window scroll and resize events. We cache scroll values so that
	   * application code can access them without triggering reflows.
	   *
	   * ViewportMetrics is only used by SyntheticMouse/TouchEvent and only when
	   * pageX/pageY isn't supported (legacy browsers).
	   *
	   * NOTE: Scroll events do not bubble.
	   *
	   * @see http://www.quirksmode.org/dom/events/scroll.html
	   */
Listens to window scroll and resize events. We cache scroll values so that
application code can access them without triggering reflows.

ViewportMetrics is only used by SyntheticMouse/TouchEvent and only when
pageX/pageY isn't supported (legacy browsers).

Scroll events do not bubble.


Listens to window scroll and resize events . We cache scroll values so that application code can access them without triggering reflows . ViewportMetrics is only used by SyntheticMouse / TouchEvent and only when pageX / pageY isn ' t supported ( legacy browsers ) . Scroll events do not bubble .
function ensureScrollValueMonitoring() {
	    if (hasEventPageXY === undefined) {
	      hasEventPageXY = document.createEvent && 'pageX' in document.createEvent('MouseEvent');
	    }
	    if (!hasEventPageXY && !isMonitoringScrollValue) {
	      var refresh = ViewportMetrics.refreshScrollValues;
	      ReactBrowserEventEmitter.ReactEventListener.monitorScrollValue(refresh);
	      isMonitoringScrollValue = true;
	    }
	  }
function ensureScrollValueMonitoring ( ) { if ( hasEventPageXY === undefined ) { hasEventPageXY = document . createEvent && 'pageX' in document . createEvent ( 'MouseEvent' ) ; } if ( ! hasEventPageXY && ! isMonitoringScrollValue ) { var refresh = ViewportMetrics . refreshScrollValues ; ReactBrowserEventEmitter . ReactEventListener . monitorScrollValue ( refresh ) ; isMonitoringScrollValue = true ; } }
Listens to window scroll and resize events.
Listens to window scroll and resize events .