Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/ui/app_list/apps_model_builder.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/app_list/apps_model_builder.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/auto_reset.h"
@@ skipping 190 matching lines @@
     }
     case chrome::NOTIFICATION_EXTENSION_LAUNCHER_REORDERED: {
       ResortApps();
       break;
     }
     case chrome::NOTIFICATION_APP_INSTALLED_TO_APPLIST: {
       highlight_app_id_ = *content::Details<const std::string>(details).ptr();
       HighlightApp();
       break;
     }
-    case chrome::NOTIFICATION_PREF_CHANGED: {
-      ResortApps();
-      break;
-    }
     default:
       NOTREACHED();
   }
 }
 
+void AppsModelBuilder::OnPreferenceChanged(PrefServiceBase* service,
+                                           const std::string& pref_name) {
+  ResortApps();
+}
+
 void AppsModelBuilder::ListItemsAdded(size_t start, size_t count) {
 }
 
 void AppsModelBuilder::ListItemsRemoved(size_t start, size_t count) {
 }
 
 void AppsModelBuilder::ListItemMoved(size_t index, size_t target_index) {
   if (ignore_changes_)
     return;
 
   ExtensionAppItem* prev = target_index > 0 ? GetAppAt(target_index - 1) : NULL;
   ExtensionAppItem* next = target_index + 1 < model_->item_count() ?
       GetAppAt(target_index + 1) : NULL;
   GetAppAt(target_index)->Move(prev, next);
 }
 
 void AppsModelBuilder::ListItemsChanged(size_t start, size_t count) {
   NOTREACHED();
 }