[gtk+] Add the private struct in class_init

[Matthias Clasen <matthiasc src gnome org>]

commit 121746605bc8efbeea1276cd657d9e1916facd8b
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Dec 17 21:50:18 2010 -0500

    Add the private struct in class_init

 gtk/gtktreestore.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtktreestore.c b/gtk/gtktreestore.c
index d2f69aa..fd0b3ff 100644
--- a/gtk/gtktreestore.c
+++ b/gtk/gtktreestore.c
@@ -222,6 +222,8 @@ gtk_tree_store_class_init (GtkTreeStoreClass *class)
   object_class = (GObjectClass *) class;
 
   object_class->finalize = gtk_tree_store_finalize;
+
+  g_type_class_add_private (class, sizeof (GtkTreeStorePrivate));
 }
 
 static void