linux: delete code that worked around gtk <2.18

chrome/browser/ui/gtk/menu_gtk.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 "chrome/browser/ui/gtk/menu_gtk.h"
 
 #include <map>
 
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
@@ skipping 783 matching lines @@
   if (GTK_IS_MENU_ITEM(widget)) {
     gtk_widget_set_sensitive(widget, model->IsEnabledAt(id));
 
     if (model->IsVisibleAt(id)) {
       // Update the menu item label if it is dynamic.
       if (model->IsItemDynamicAt(id)) {
         std::string label =
             gfx::ConvertAcceleratorsFromWindowsStyle(
                 UTF16ToUTF8(model->GetLabelAt(id)));
 
-#if GTK_CHECK_VERSION(2, 16, 0)
         gtk_menu_item_set_label(GTK_MENU_ITEM(widget), label.c_str());
-#else
-        gtk_label_set_label(GTK_LABEL(GTK_BIN(widget)->child), label.c_str());
-#endif
         if (GTK_IS_IMAGE_MENU_ITEM(widget)) {
           SkBitmap icon;
           if (model->GetIconAt(id, &icon)) {
             GdkPixbuf* pixbuf = gfx::GdkPixbufFromSkBitmap(&icon);
             gtk_image_menu_item_set_image(GTK_IMAGE_MENU_ITEM(widget),
                                           gtk_image_new_from_pixbuf(pixbuf));
             g_object_unref(pixbuf);
           } else {
             gtk_image_menu_item_set_image(GTK_IMAGE_MENU_ITEM(widget), NULL);
           }
         }
       }
 
       gtk_widget_show(widget);
     } else {
       gtk_widget_hide(widget);
     }
 
     GtkWidget* submenu = gtk_menu_item_get_submenu(GTK_MENU_ITEM(widget));
     if (submenu) {
       gtk_container_foreach(GTK_CONTAINER(submenu), &SetMenuItemInfo,
                             userdata);
     }
   }
 }