[gtk+/gtk-2-24] Do not leak a cairo region

[Matthias Clasen <matthiasc src gnome org>]

commit aff976ef0dad471edc35d65b9d1b5ba97da1698e
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Oct 20 06:17:56 2014 -0400

    Do not leak a cairo region
    
    This memory leak fix was present in GTK+ 3 since 3.10. We forgot
    to backport it to GTK+ 2.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=738837

 gdk/gdkwindow.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index 153144a..386e85d 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -8747,6 +8747,8 @@ do_child_shapes (GdkWindow *window,
     gdk_region_subtract (region, private->shape);
 
   gdk_window_shape_combine_region (window, region, 0, 0);
+
+  cairo_region_destroy (region);
 }
 
 /**