[gtk/present-toplevel-2: 30/33] toplevel: require GdkSurface

[Matthias Clasen <matthiasc src gnome org>]

commit 3c9fb79603e607f117d6eb63b69d656ee0ec699f
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Mar 10 07:24:04 2020 -0400

    toplevel: require GdkSurface

 gdk/gdktoplevel.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)
---
diff --git a/gdk/gdktoplevel.c b/gdk/gdktoplevel.c
index 9848187e08..d5d0877d27 100644
--- a/gdk/gdktoplevel.c
+++ b/gdk/gdktoplevel.c
@@ -31,11 +31,7 @@
  * A #GdkToplevel is a freestanding toplevel surface.
  */
 
-
-/* FIXME: this can't have GdkSurface as a prerequisite
- * as long as GdkSurface implements this interface itself
- */
-G_DEFINE_INTERFACE (GdkToplevel, gdk_toplevel, G_TYPE_OBJECT)
+G_DEFINE_INTERFACE (GdkToplevel, gdk_toplevel, GDK_TYPE_SURFACE)
 
 static gboolean
 gdk_toplevel_default_present (GdkToplevel       *toplevel,