nsIViewManager* vm = nsnull; mParent->GetViewManager(vm); if (nsnull != vm)
nsCOMPtr<nsIViewManager> vm; mParent->GetViewManager(*getter_AddRefs(vm)); if (vm)
  virtual ~nsZPlaceholderView()  { if (nsnull != mReparentedChild) {      mReparentedChild->SetZParent(nsnull);    }    if (nsnull != mParent)    {      nsIViewManager* vm = nsnull;      mParent->GetViewManager(vm);      if (nsnull != vm)      {        vm->RemoveChild(mParent, this);      }      else      {        mParent->RemoveChild(this);      }    }  }