[gtk+] Do not leak cairo_region

[Paolo Borelli <pborelli src gnome org>]

commit e34d9eafed41bd4c5ac4cb28fd5fb0ff8aee7275
Author: Paolo Borelli <pborelli gnome org>
Date:   Fri Feb 21 21:07:11 2014 +0100

    Do not leak cairo_region

 gdk/gdkwindow.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index 606c45c..3f89d86 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -6424,6 +6424,8 @@ do_child_shapes (GdkWindow *window,
   cairo_region_xor_rectangle (region, &r);
 
   gdk_window_shape_combine_region (window, region, 0, 0);
+
+  cairo_region_destroy (region);
 }
 
 /**