nsZPlaceholderView(nsView* aParent) : nsView() { SetParent(aParent); SetVisibility(nsViewVisibility_kHide); }
nsZPlaceholderView() : nsView() {}
  nsZPlaceholderView(nsView* aParent) : nsView() {    SetParent(aParent);    SetVisibility(nsViewVisibility_kHide);  }