[gtk+] Add a migration guide section about resize grips

[Matthias Clasen <matthiasc src gnome org>]

commit f8490e425f2c76533bc1733989d176c8a5ca06f7
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Oct 8 02:18:15 2010 -0400

    Add a migration guide section about resize grips

 docs/reference/gtk/migrating-2to3.xml |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)
---
diff --git a/docs/reference/gtk/migrating-2to3.xml b/docs/reference/gtk/migrating-2to3.xml
index 81fa827..121c448 100644
--- a/docs/reference/gtk/migrating-2to3.xml
+++ b/docs/reference/gtk/migrating-2to3.xml
@@ -663,6 +663,18 @@ gtk_arrow_draw (GtkWidget *widget,
   </section>
 
   <section>
+    <title>Resize grips</title>
+
+    <para>
+     The resize grip functionality has been moved from #GtkStatusbar
+     to #GtkWindow. Any window can now have resize grips, regardless whether
+     it has a statusbar or not. The functions
+     gtk_statusbar_set_has_resize_grip() and gtk_statusbar_get_has_resize_grip()
+     have disappeared, and instead there are now
+     gtk_window_set_has_resize_grip() and gtk_window_get_has_resize_grip().
+  </section>
+
+  <section>
     <title>Prevent mixed linkage</title>
     <para>
       Linking against GTK+ 2.x and GTK+ 3 in the same process is problematic