anchor.diff:      } else {
         _initialWritePending = true;
         _domService.scheduleWrite(() {
  +        _element.classes.toggle(_hideClassLegacy, !value);
           _element.classes.toggle(_hideClass, !value);
  +        _element.classes.toggle(_hiddenClassLegacy, !value);
           _element.classes.toggle(_hiddenClass, !value);
           _initialWritePending = false;
         });
  
positive.code: 
  /// Shows or hides the given HTML element based on an expression.
  ///
  /// The element is shown or hidden by removing or adding the 'ng-hide' css
  /// class at first, and 'ng-hidden' at the end of transition (or after 16ms
  /// delay if no transition happened).
  @Directive(
    selector: '[showhide]',
  )
  class ShowHideDirective implements OnInit, OnDestroy {
    static String _hideClass = 'ng-hide';
    static String _hiddenClass = 'ng-hidden';
    // time after transition started, when ng-hidden is added forcefully
    static int _transitionTimeoutMs = 16;
  
    final Element _element;
  
negative.code:   void _hideIfHiding() {
      if (_hiding) {
        _domService.scheduleWrite(() {
          _element.classes.add(_hiddenClassLegacy);
          _element.classes.add(_hiddenClass);
        });
        _onHideEnd.add(_element);
  