[gtk+] testoverlay: Fix test by using add_pass_through_overlay

[Alexander Larsson <alexl src gnome org>]

commit a9bf6532b4ac4d6a3bc0bccd87d8bacb7e828c7e
Author: Alexander Larsson <alexl redhat com>
Date:   Mon Jun 8 16:30:40 2015 +0200

    testoverlay: Fix test by using add_pass_through_overlay
    
    https://bugzilla.gnome.org/show_bug.cgi?id=750568
    
    https://bugs.freedesktop.org/show_bug.cgi?id=90917

 tests/testoverlay.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/tests/testoverlay.c b/tests/testoverlay.c
index 23718b8..c2c2cad 100644
--- a/tests/testoverlay.c
+++ b/tests/testoverlay.c
@@ -440,7 +440,7 @@ test_input_stacking (void)
     }
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-  gtk_overlay_add_overlay (GTK_OVERLAY (overlay), vbox);
+  gtk_overlay_add_pass_through_overlay (GTK_OVERLAY (overlay), vbox);
   gtk_widget_set_halign (vbox, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (vbox, GTK_ALIGN_CENTER);