[gtk/kill-hierarchy-changed: 14/14] Document that root and unroot must chain up

[Matthias Clasen <matthiasc src gnome org>]

commit 89470ab2013124b696c7daba6b6dd046dfeb48dc
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Feb 23 09:19:14 2019 -0500

    Document that root and unroot must chain up
    
    I overlooked this at first.

 gtk/gtkwidget.h | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/gtk/gtkwidget.h b/gtk/gtkwidget.h
index be8a413544..db4a81272c 100644
--- a/gtk/gtkwidget.h
+++ b/gtk/gtkwidget.h
@@ -152,9 +152,8 @@ struct _GtkWidget
  *   widget is destroyed, which means that gtk_widget_unrealize() has
  *   been called or the widget has been unmapped (that is, it is going
  *   to be hidden).
- * @root: Called when the widget gets added to a #GtkRoot widget.
- * @unroot: Called when the widget is about to be removed from its
- *   #GtkRoot widget.
+ * @root: Called when the widget gets added to a #GtkRoot widget. Must chain up
+ * @unroot: Called when the widget is about to be removed from its #GtkRoot widget. Must chain up
  * @size_allocate: Signal emitted to get the widget allocation.
  * @state_flags_changed: Signal emitted when the widget state changes,
  *   see gtk_widget_get_state_flags().