anchor.diff:    // 'slot' is the identifier that the ancestor RenderObjectWrapper uses to know
     // where to put this descendant. If you just defer to a child, then make sure
     // to pass them the slot.
  -
  -  Widget findAncestorRenderObjectWrapper() {
  -    var ancestor = _parent;
  -    while (ancestor != null && ancestor is! RenderObjectWrapper)
  -      ancestor = ancestor._parent;
  -    return ancestor;
  -  }
   
     Set<Type> _dependencies;
     Inherited inheritedOfType(Type targetType) {
  
positive.code:     newNode._ancestor = _ancestor;
    }
  
    void _sync(RenderObjectWrapper old, dynamic slot) {
      // TODO(abarth): We should split RenderObjectWrapper into two pieces so that
      //               RenderViewObject doesn't need to inherit all this code it
  
negative.code:       _renderObject = createNode();
        assert(_renderObject != null);
        _ancestor = findAncestorRenderObjectWrapper();
        if (_ancestor != null)
          _ancestor.insertChildRenderObject(this, slot);
      } else {
        _renderObject = old.renderObject;
  