Remove NOTIFICATION_SYSTEM_SETTING_CHANGED, switch CrosSettings to base::CallbackRegistry.

chrome/browser/chromeos/policy/app_pack_updater.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_POLICY_APP_PACK_UPDATER_H_
 #define CHROME_BROWSER_CHROMEOS_POLICY_APP_PACK_UPDATER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/chromeos/extensions/external_cache.h"
-#include "content/public/browser/notification_observer.h"
+#include "chrome/browser/chromeos/settings/cros_settings.h"
 
 namespace extensions {
 class ExternalLoader;
 }
 
 namespace net {
 class URLRequestContextGetter;
 }
 
 namespace policy {
 
 class AppPackExternalLoader;
 class EnterpriseInstallAttributes;
 
 // The AppPackUpdater manages a set of extensions that are configured via a
 // device policy to be locally cached and installed into the Demo user account
 // at login time.
-class AppPackUpdater : public content::NotificationObserver,
-                       public chromeos::ExternalCache::Delegate {
+class AppPackUpdater : public chromeos::ExternalCache::Delegate {
  public:
   // Callback to listen for updates to the screensaver extension's path.
   typedef base::Callback<void(const base::FilePath&)> ScreenSaverUpdateCallback;
 
   // The |request_context| is used for the update checks.
   AppPackUpdater(net::URLRequestContextGetter* request_context,
                  EnterpriseInstallAttributes* install_attributes);
   virtual ~AppPackUpdater();
 
   // Returns true if the ExternalLoader for the app pack has already been
@@ skipping 10 matching lines @@
   // exists. Subsequent calls will override the previous |callback|. A null
   // |callback| can be used to remove a previous callback.
   void SetScreenSaverUpdateCallback(const ScreenSaverUpdateCallback& callback);
 
   // If a user of one of the AppPack's extensions detects that the extension
   // is damaged then this method can be used to remove it from the cache and
   // retry to download it after a restart.
   void OnDamagedFileDetected(const base::FilePath& path);
 
  private:
-  // content::NotificationObserver:
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
-
   // Implementation of ExternalCache::Delegate:
   virtual void OnExtensionListsUpdated(
       const base::DictionaryValue* prefs) OVERRIDE;
 
+  // Called when the app pack device setting changes.
+  void AppPackChanged();
+
   // Loads the current policy and schedules a cache update.
   void LoadPolicy();
 
   // Notifies the |extension_loader_| that the cache has been updated, providing
   // it with an updated list of app-pack extensions.
   void UpdateExtensionLoader();
 
   // Sets |screen_saver_path_| and invokes |screen_saver_update_callback_| if
   // appropriate.
   void SetScreenSaverPath(const base::FilePath& path);
@@ skipping 13 matching lines @@
   // makes it install the currently cached extensions.
   bool created_extension_loader_;
   base::WeakPtr<AppPackExternalLoader> extension_loader_;
 
   // For checking the device mode.
   EnterpriseInstallAttributes* install_attributes_;
 
   // Extension cache.
   chromeos::ExternalCache external_cache_;
 
+  scoped_ptr<chromeos::CrosSettings::ObserverSubscription>
+      app_pack_subscription_;
+
   DISALLOW_COPY_AND_ASSIGN(AppPackUpdater);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_CHROMEOS_POLICY_APP_PACK_UPDATER_H_