code: function startWatchingForValueChange(target, targetInst) {
  	  activeElement = target;
  	  activeElementInst = targetInst;
  	  activeElementValue = target.value;
  	  activeElementValueProp = Object.getOwnPropertyDescriptor(target.constructor.prototype, 'value');
  
  	  // Not guarded in a canDefineProperty check: IE8 supports defineProperty only
  	  // on DOM elements
  	  Object.defineProperty(activeElement, 'value', newValueProp);
  	  if (activeElement.attachEvent) {
  	    activeElement.attachEvent('onpropertychange', handlePropertyChange);
  	  } else {
  	    activeElement.addEventListener('propertychange', handlePropertyChange, false);
  	  }
  	}
docs: (For IE <=11) Starts tracking propertychange events on the passed-in element
  and override the value property so that we can distinguish user events from
  value changes in JS.