GTK: Make the gtk port compile with GTK_DISABLE_SINGLE_INCLUDES.

ui/gfx/gtk_preserve_window.cc

 // 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.
 
 #include "ui/gfx/gtk_preserve_window.h"
 
-#include <gdk/gdkwindow.h>
+#include <gdk/gdk.h>
 #include <gtk/gtk.h>
-#include <gtk/gtkwidget.h>
-#include <gtk/gtkfixed.h>
 
 G_BEGIN_DECLS
 
 #define GTK_PRESERVE_WINDOW_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), \
                                             GTK_TYPE_PRESERVE_WINDOW, \
                                             GtkPreserveWindowPrivate))
 
 typedef struct _GtkPreserveWindowPrivate GtkPreserveWindowPrivate;
 
 struct _GtkPreserveWindowPrivate {
@@ skipping 203 matching lines @@
   }
 }
 
 void gtk_preserve_window_delegate_resize(GtkPreserveWindow* widget,
                                          gboolean delegate) {
   GtkPreserveWindowPrivate* priv = GTK_PRESERVE_WINDOW_GET_PRIVATE(widget);
   priv->delegate_resize = delegate;
 }
 
 G_END_DECLS