GTK: Make the gtk port compile with GTK_DISABLE_SINGLE_INCLUDES.

chrome/browser/ui/gtk/gtk_custom_menu.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_GTK_GTK_CUSTOM_MENU_H_
 #define CHROME_BROWSER_UI_GTK_GTK_CUSTOM_MENU_H_
 #pragma once
 
 // GtkCustomMenu is a GtkMenu subclass that can contain, and collaborates with,
 // GtkCustomMenuItem instances. GtkCustomMenuItem is a GtkMenuItem that can
 // have buttons and other normal widgets embeded in it. GtkCustomMenu exists
 // only to override most of the button/motion/move callback functions so
 // that the normal GtkMenu implementation doesn't handle events related to
 // GtkCustomMenuItem items.
 //
 // For a more through overview of this system, see the comments in
 // gtk_custom_menu_item.h.
 
-#include <gdk/gdk.h>
 #include <gtk/gtk.h>
-#include <gtk/gtkmenuitem.h>
 
 G_BEGIN_DECLS
 
 #define GTK_TYPE_CUSTOM_MENU                                            \
   (gtk_custom_menu_get_type())
 #define GTK_CUSTOM_MENU(obj)                                            \
   (G_TYPE_CHECK_INSTANCE_CAST((obj), GTK_TYPE_CUSTOM_MENU, GtkCustomMenu))
 #define GTK_CUSTOM_MENU_CLASS(klass)                                    \
   (G_TYPE_CHECK_CLASS_CAST((klass), GTK_TYPE_CUSTOM_MENU, GtkCustomMenuClass))
 #define GTK_IS_CUSTOM_MENU(obj)                                         \
@@ skipping 13 matching lines @@
 struct _GtkCustomMenuClass {
   GtkMenuClass parent_class;
 };
 
 GType gtk_custom_menu_get_type(void) G_GNUC_CONST;
 GtkWidget* gtk_custom_menu_new();
 
 G_END_DECLS
 
 #endif  // CHROME_BROWSER_UI_GTK_GTK_CUSTOM_MENU_H_