anchor.diff:      if (renderViewOverride == null) {
         _renderView = new RenderView(child: root);
         _renderView.attach();
  -      _renderView.rootConstraints = _createConstraints();
  +      _handleMetricsChanged();
         _renderView.scheduleInitialFrame();
       } else {
         _renderView = renderViewOverride;
  
positive.code:     if (ourEvent is PointerInputEvent) {
        _handlePointerInputEvent(ourEvent);
      } else {
        for (EventListener listener in _eventListeners)
          listener(ourEvent);
      }
  
negative.code:   }
    return weight;
  }
  
  /// A hit test entry used by [FlutterBinding]
  class BindingHitTestEntry extends HitTestEntry {
  