Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/ui/gtk/global_menu_bar.cc

 // Copyright (c) 2012 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/global_menu_bar.h"
 
 #include <gtk/gtk.h>
 
 #include "base/command_line.h"
 #include "chrome/app/chrome_command_ids.h"
@@ skipping 263 matching lines @@
   gtk_widget_show(menu_item);
   return menu_item;
 }
 
 void GlobalMenuBar::EnabledStateChangedForCommand(int id, bool enabled) {
   CommandIDMenuItemMap::iterator it = id_to_menu_item_.find(id);
   if (it != id_to_menu_item_.end())
     gtk_widget_set_sensitive(it->second, enabled);
 }
 
-void GlobalMenuBar::Observe(int type,
-                            const content::NotificationSource& source,
-                            const content::NotificationDetails& details) {
-  DCHECK_EQ(chrome::NOTIFICATION_PREF_CHANGED, type);
-  const std::string& pref_name = *content::Details<std::string>(details).ptr();
+void GlobalMenuBar::OnPreferenceChanged(PrefServiceBase* service,
+                                        const std::string& pref_name) {
   DCHECK_EQ(prefs::kShowBookmarkBar, pref_name);
   OnBookmarkBarVisibilityChanged();
 }
 
 void GlobalMenuBar::OnBookmarkBarVisibilityChanged() {
   CommandIDMenuItemMap::iterator it =
       id_to_menu_item_.find(IDC_SHOW_BOOKMARK_BAR);
   if (it != id_to_menu_item_.end()) {
     PrefService* prefs = browser_->profile()->GetPrefs();
     block_activation_ = true;
     gtk_check_menu_item_set_active(
         GTK_CHECK_MENU_ITEM(it->second),
         prefs->GetBoolean(prefs::kShowBookmarkBar));
     block_activation_ = false;
   }
 }
 
 void GlobalMenuBar::OnItemActivated(GtkWidget* sender) {
   if (block_activation_)
     return;
 
   int id = GPOINTER_TO_INT(g_object_get_data(G_OBJECT(sender), "command-id"));
   chrome::ExecuteCommand(browser_, id);
 }