Make the hcsm and its providers communicate via an observer interface.

chrome/browser/content_settings/content_settings_policy_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_POLICY_PROVIDER_H_
 #define CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_POLICY_PROVIDER_H_
 #pragma once
 
 // A content settings provider that takes its settings out of policies.
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/synchronization/lock.h"
 #include "base/tuple.h"
+#include "chrome/browser/content_settings/content_settings_observable_provider.h"
 #include "chrome/browser/content_settings/content_settings_origin_identifier_value_map.h"
-#include "chrome/browser/content_settings/content_settings_provider.h"
 #include "chrome/browser/prefs/pref_change_registrar.h"
 #include "content/common/notification_observer.h"
 #include "content/common/notification_registrar.h"
 
 class ContentSettingsDetails;
 class DictionaryValue;
 class HostContentSettingsMap;
 class PrefService;
 
 namespace content_settings {
@@ skipping 43 matching lines @@
   // guarantee thread safety.
   mutable base::Lock lock_;
 
   PrefChangeRegistrar pref_change_registrar_;
   NotificationRegistrar notification_registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(PolicyDefaultProvider);
 };
 
 // PolicyProvider that provider managed content-settings.
-class PolicyProvider : public ProviderInterface,
+class PolicyProvider : public ObservableProvider,
                        public NotificationObserver {
  public:
-  PolicyProvider(HostContentSettingsMap* map,
-                 PrefService* prefs,
+  PolicyProvider(PrefService* prefs,
                  DefaultProviderInterface* default_provider);
   virtual ~PolicyProvider();
   static void RegisterUserPrefs(PrefService* prefs);
 
-  // ProviderInterface Implementation
+  // ProviderInterface implementations.
   virtual void SetContentSetting(
       const ContentSettingsPattern& primary_pattern,
       const ContentSettingsPattern& secondary_pattern,
       ContentSettingsType content_type,
       const ResourceIdentifier& resource_identifier,
       ContentSetting content_setting);
 
   virtual ContentSetting GetContentSetting(
       const GURL& primary_url,
       const GURL& secondary_url,
@@ skipping 23 matching lines @@
       ContentSetting> ContentSettingsRule;
 
   typedef std::vector<ContentSettingsRule> ContentSettingsRules;
 
   void ReadManagedContentSettings(bool overwrite);
 
   void GetContentSettingsFromPreferences(ContentSettingsRules* rules);
 
   void ReadManagedContentSettingsTypes(ContentSettingsType content_type);
 
-  void NotifyObservers(const ContentSettingsDetails& details);
-
   OriginIdentifierValueMap value_map_;
 
-  HostContentSettingsMap* host_content_settings_map_;
   PrefService* prefs_;
 
   // Weak, owned by HostContentSettingsMap.
   DefaultProviderInterface* default_provider_;
 
   PrefChangeRegistrar pref_change_registrar_;
 
   // Used around accesses to the content_settings_ object to guarantee
   // thread safety.
   mutable base::Lock lock_;
 
   DISALLOW_COPY_AND_ASSIGN(PolicyProvider);
 };
 
 }  // namespace content_settings
 
 #endif  // CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_POLICY_PROVIDER_H_