Remove NOTIFICATION_SYSTEM_SETTING_CHANGED, switch CrosSettings to base::CallbackRegistry.

chrome/browser/chromeos/settings/cros_settings.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_SETTINGS_CROS_SETTINGS_H_
 #define CHROME_BROWSER_CHROMEOS_SETTINGS_CROS_SETTINGS_H_
 
 #include <string>
 #include <vector>
 
 #include "base/callback_forward.h"
+#include "base/callback_registry.h"
 #include "base/containers/hash_tables.h"
-#include "base/observer_list.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/threading/non_thread_safe.h"
 #include "chrome/browser/chromeos/settings/cros_settings_names.h"
 #include "chrome/browser/chromeos/settings/cros_settings_provider.h"
-#include "content/public/browser/notification_observer.h"
 
 namespace base {
 class DictionaryValue;
 class ListValue;
 class Value;
 }
 
 namespace chromeos {
 
 class DeviceSettingsService;
@@ skipping 58 matching lines @@
 
   // Helper function for the whitelist op. Implemented here because we will need
   // this in a few places. The functions searches for |email| in the pref |path|
   // It respects whitelists so foo@bar.baz will match *@bar.baz too.
   bool FindEmailInList(const std::string& path, const std::string& email) const;
 
   // Adding/removing of providers.
   bool AddSettingsProvider(CrosSettingsProvider* provider);
   bool RemoveSettingsProvider(CrosSettingsProvider* provider);
 
-  // If the pref at the given |path| changes, we call the observer's Observe
-  // method with NOTIFICATION_SYSTEM_SETTING_CHANGED.
-  void AddSettingsObserver(const char* path,
-                           content::NotificationObserver* obs);
-  void RemoveSettingsObserver(const char* path,
-                              content::NotificationObserver* obs);
+  // Add an observer Callback for changes for the given |path|.
+  typedef base::CallbackRegistry<void>::Subscription ObserverSubscription;
+  scoped_ptr<ObserverSubscription> AddSettingsObserver(
+      const std::string& path,
+      const base::Closure& callback);
 
   // Returns the provider that handles settings with the |path| or prefix.
   CrosSettingsProvider* GetProvider(const std::string& path) const;
 
  private:
   friend class CrosSettingsTest;
 
-  // Fires system setting change notification.
+  // Fires system setting change callback.
   void FireObservers(const std::string& path);
 
   // List of ChromeOS system settings providers.
   std::vector<CrosSettingsProvider*> providers_;
 
   // A map from settings names to a list of observers. Observers get fired in
   // the order they are added.
-  typedef ObserverList<content::NotificationObserver, true>
-      NotificationObserverList;
-  typedef base::hash_map<std::string, NotificationObserverList*>
+  typedef base::hash_map<std::string, base::CallbackRegistry<void>*>
       SettingsObserverMap;
   SettingsObserverMap settings_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(CrosSettings);
 };
 
 // Helper class for tests. Initializes the CrosSettings singleton on
 // construction and tears it down again on destruction.
 class ScopedTestCrosSettings {
  public:
   ScopedTestCrosSettings();
   ~ScopedTestCrosSettings();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ScopedTestCrosSettings);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_SETTINGS_CROS_SETTINGS_H_