Draft change to use base::Closure instead of PrefObserver in PrefChangeRegistrar.

chrome/browser/ui/ash/launcher/chrome_launcher_controller.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/ash/launcher/chrome_launcher_controller.h"
 
 #include <set>
 #include <vector>
 
 #include "ash/launcher/launcher_model.h"
@@ skipping 824 matching lines @@
     return;
   }
 
   // Set kUseDefaultPinnedApps to false and use pinned apps list from prefs
   // from now on.
   profile_->GetPrefs()->SetBoolean(prefs::kUseDefaultPinnedApps, false);
 
   // Mutating kPinnedLauncherApps is going to notify us and trigger us to
   // process the change. We don't want that to happen so remove ourselves as a
   // listener.
-  pref_change_registrar_.Remove(prefs::kPinnedLauncherApps, this);
+  pref_change_registrar_.Remove(prefs::kPinnedLauncherApps);
   {
     ListPrefUpdate updater(profile_->GetPrefs(), prefs::kPinnedLauncherApps);
     updater->Clear();
     for (size_t i = 0; i < model_->items().size(); ++i) {
       if (model_->items()[i].type == ash::TYPE_APP_SHORTCUT) {
         ash::LauncherID id = model_->items()[i].id;
         if (HasItemController(id) && IsPinned(id)) {
           base::DictionaryValue* app_value = ash::CreateAppDict(
               id_to_item_controller_map_[id]->app_id());
           if (app_value)
@@ skipping 216 matching lines @@
       new AppShortcutLauncherItemController(app_id, this);
   ash::LauncherID launcher_id = InsertAppLauncherItem(
       controller, app_id, ash::STATUS_CLOSED, index);
   return launcher_id;
 }
 
 bool ChromeLauncherController::HasItemController(ash::LauncherID id) const {
   return id_to_item_controller_map_.find(id) !=
          id_to_item_controller_map_.end();
 }