Remove NOTIFICATION_SYSTEM_SETTING_CHANGED, switch CrosSettings to base::CallbackRegistry.

chrome/browser/chromeos/login/version_info_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_LOGIN_VERSION_INFO_UPDATER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_VERSION_INFO_UPDATER_H_
 
 #include <string>
 
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/chromeos/boot_times_loader.h"
+#include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chrome/browser/chromeos/version_loader.h"
 #include "chrome/browser/policy/cloud/cloud_policy_store.h"
-#include "content/public/browser/notification_observer.h"
 
 namespace chromeos {
 
 class CrosSettings;
 
 // Fetches all info we want to show on OOBE/Login screens about system
 // version, boot times and cloud policy.
-class VersionInfoUpdater : public policy::CloudPolicyStore::Observer,
-                           public content::NotificationObserver {
+class VersionInfoUpdater : public policy::CloudPolicyStore::Observer {
  public:
   class Delegate {
    public:
     virtual ~Delegate() {}
 
     // Called when OS version label should be updated.
     virtual void OnOSVersionLabelTextUpdated(
         const std::string& os_version_label_text) = 0;
 
     // Called when the enterprise info notice should be updated.
     virtual void OnEnterpriseInfoUpdated(
         const std::string& enterprise_info) = 0;
   };
 
   explicit VersionInfoUpdater(Delegate* delegate);
   virtual ~VersionInfoUpdater();
 
   // Sets delegate.
   void set_delegate(Delegate* delegate) { delegate_ = delegate; }
 
   // Starts fetching version info. The delegate will be notified when update
   // is received.
   void StartUpdate(bool is_official_build);
 
  private:
   // policy::CloudPolicyStore::Observer interface:
   virtual void OnStoreLoaded(policy::CloudPolicyStore* store) OVERRIDE;
   virtual void OnStoreError(policy::CloudPolicyStore* store) OVERRIDE;
 
-  // content::NotificationObserver interface.
-  virtual void Observe(
-      int type,
-      const content::NotificationSource& source,
-      const content::NotificationDetails& details) OVERRIDE;
-
   // Update the version label.
   void UpdateVersionLabel();
 
   // Check and update enterprise domain.
   void UpdateEnterpriseInfo();
 
   // Set enterprise domain name.
   void SetEnterpriseInfo(const std::string& domain_name);
 
   // Callback from chromeos::VersionLoader giving the version.
   void OnVersion(const std::string& version);
 
   // Handles asynchronously loading the version.
   VersionLoader version_loader_;
   // Handles asynchronously loading the boot times.
   BootTimesLoader boot_times_loader_;
   // Used to request version and boot times.
   CancelableTaskTracker tracker_;
 
   // Information pieces for version label.
   std::string version_text_;
 
   // Full text for the OS version label.
   std::string os_version_label_text_;
 
+  scoped_ptr<CrosSettings::ObserverSubscription> version_info_subscription_;
+  scoped_ptr<CrosSettings::ObserverSubscription> activity_times_subscription_;
+  scoped_ptr<CrosSettings::ObserverSubscription> boot_mode_subscription_;
+  scoped_ptr<CrosSettings::ObserverSubscription> location_subscription_;
+
   chromeos::CrosSettings* cros_settings_;
 
   Delegate* delegate_;
 
   // Weak pointer factory so we can give our callbacks for invocation
   // at a later time without worrying that they will actually try to
   // happen after the lifetime of this object.
   base::WeakPtrFactory<VersionInfoUpdater> weak_pointer_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VersionInfoUpdater);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_VERSION_INFO_UPDATER_H_