Add a 'hidden' parameter to RenderViewContextMenuProxy::UpdateMenuItem().

chrome/browser/tab_contents/render_view_context_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/tab_contents/render_view_context_menu_gtk.h"
 
 #include <gtk/gtk.h>
 
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
@@ skipping 110 matching lines @@
   menu_gtk_->PopupAsContext(point, triggering_event_time_);
 }
 
 bool RenderViewContextMenuGtk::AlwaysShowIconForCmd(int command_id) const {
   return command_id >= IDC_EXTENSIONS_CONTEXT_CUSTOM_FIRST &&
       command_id <= IDC_EXTENSIONS_CONTEXT_CUSTOM_LAST;
 }
 
 void RenderViewContextMenuGtk::UpdateMenuItem(int command_id,
                                               bool enabled,
+                                              bool hidden,
                                               const string16& title) {
   GtkWidget* item = GetMenuItemByID(&menu_model_, menu_gtk_->widget(),
                                     command_id);
   if (!item || !GTK_IS_MENU_ITEM(item))
     return;
 
   // Enable (or disable) the menu item and updates its text.
   gtk_widget_set_sensitive(item, enabled);
+  if (hidden)
+    gtk_widget_hide(item);
+  else
+    gtk_widget_show(item);
   gtk_menu_item_set_label(GTK_MENU_ITEM(item), UTF16ToUTF8(title).c_str());
 }