[gtk+] notebook: Don't leak arrow gadgets

[Matthias Clasen <matthiasc src gnome org>]

commit 1dded6d63395360981f51d8cd58246bfa5c9d31e
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Nov 23 14:44:37 2016 -0500

    notebook: Don't leak arrow gadgets
    
    This was pointed out in
    https://bugzilla.gnome.org/show_bug.cgi?id=774743

 gtk/gtknotebook.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtknotebook.c b/gtk/gtknotebook.c
index 02939bb..8909d18 100644
--- a/gtk/gtknotebook.c
+++ b/gtk/gtknotebook.c
@@ -1743,6 +1743,10 @@ gtk_notebook_finalize (GObject *object)
   g_clear_object (&priv->gadget);
   g_clear_object (&priv->header_gadget);
   g_clear_object (&priv->tabs_gadget);
+  g_clear_object (&priv->arrow_gadget[0]);
+  g_clear_object (&priv->arrow_gadget[1]);
+  g_clear_object (&priv->arrow_gadget[2]);
+  g_clear_object (&priv->arrow_gadget[3]);
   g_clear_object (&priv->stack_gadget);
   g_clear_object (&priv->press_gesture);