Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/content_settings/content_settings_default_provider.h

 // Copyright (c) 2011 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_CONTENT_SETTINGS_CONTENT_SETTINGS_DEFAULT_PROVIDER_H_
 #define CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_DEFAULT_PROVIDER_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/linked_ptr.h"
 #include "base/prefs/public/pref_change_registrar.h"
+#include "base/prefs/public/pref_observer.h"
 #include "base/synchronization/lock.h"
 #include "chrome/browser/content_settings/content_settings_observable_provider.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
 
 class PrefService;
 
 namespace content_settings {
 
 // Provider that provides default content settings based on
 // user prefs. If no default values are set by the user we use the hard coded
 // default values.
 class DefaultProvider : public ObservableProvider,
-                        public content::NotificationObserver {
+                        public PrefObserver {
  public:
   static void RegisterUserPrefs(PrefService* prefs);
 
   DefaultProvider(PrefService* prefs,
                   bool incognito);
   virtual ~DefaultProvider();
 
   // ProviderInterface implementations.
   virtual RuleIterator* GetRuleIterator(
       ContentSettingsType content_type,
       const ResourceIdentifier& resource_identifier,
       bool incognito) const OVERRIDE;
 
   virtual bool SetWebsiteSetting(
       const ContentSettingsPattern& primary_pattern,
       const ContentSettingsPattern& secondary_pattern,
       ContentSettingsType content_type,
       const ResourceIdentifier& resource_identifier,
       Value* value) OVERRIDE;
 
   virtual void ClearAllContentSettingsRules(
       ContentSettingsType content_type) OVERRIDE;
 
   virtual void ShutdownOnUIThread() OVERRIDE;
 
-  // content::NotificationObserver implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
+  // PrefObserver implementation.
+  virtual void OnPreferenceChanged(PrefServiceBase* service,
+                                   const std::string& pref_name) OVERRIDE;
 
  private:
   // Sets the fields of |settings| based on the values in |dictionary|.
   void GetSettingsFromDictionary(const base::DictionaryValue* dictionary);
 
   // Forces the default settings to be explicitly set instead of themselves
   // being CONTENT_SETTING_DEFAULT.
   void ForceDefaultsToBeExplicit();
 
   // Reads the default settings from the preferences service. If |overwrite| is
@@ skipping 22 matching lines @@
   // Whether we are currently updating preferences, this is used to ignore
   // notifications from the preferences service that we triggered ourself.
   bool updating_preferences_;
 
   DISALLOW_COPY_AND_ASSIGN(DefaultProvider);
 };
 
 }  // namespace content_settings
 
 #endif  // CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_DEFAULT_PROVIDER_H_