Make ExtensionContentSettingsStore refcounted.

chrome/browser/extensions/extension_content_settings_store.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_EXTENSIONS_EXTENSION_CONTENT_SETTINGS_STORE_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_CONTENT_SETTINGS_STORE_H_
 
 #include <list>
 #include <map>
 #include <string>
 
 #include "base/observer_list.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_checker.h"
 #include "base/time.h"
 #include "base/tuple.h"
 #include "chrome/browser/content_settings/content_settings_pattern.h"
 #include "chrome/browser/content_settings/content_settings_provider.h"
 #include "chrome/browser/extensions/extension_prefs_scope.h"
 #include "chrome/common/content_settings.h"
 #include "googleurl/src/gurl.h"
 
 class DictionaryValue;
 class ListValue;
 
 // This class is the backend for extension-defined content settings. It is used
 // by the content_settings::ExtensionProvider to integrate its settings into the
 // HostContentSettingsMap and by the content settings extension API to provide
 // extensions with access to content settings.
-class ExtensionContentSettingsStore {
+class ExtensionContentSettingsStore
+    : public base::RefCountedThreadSafe<ExtensionContentSettingsStore> {
  public:
   class Observer {
    public:
     virtual ~Observer() {}
 
     // Called when a content setting changes in the
     // ExtensionContentSettingsStore.
     virtual void OnContentSettingChanged(
         const std::string& extension_id,
         bool incognito) = 0;
-
-    // Called when the ExtensionContentSettingsStore is being destroyed, so
-    // observers can invalidate their weak references.
-    virtual void OnDestruction() = 0;
   };
 
   ExtensionContentSettingsStore();
-  virtual ~ExtensionContentSettingsStore();
 
   // //////////////////////////////////////////////////////////////////////////
 
   // Sets the content |setting| for |pattern| of extension |ext_id|. The
   // |incognito| flag allow to set whether the provided setting is for
   // incognito mode only.
   // Precondition: the extension must be registered.
   // This method should only be called on the UI thread.
   void SetExtensionContentSetting(
       const std::string& ext_id,
@@ skipping 50 matching lines @@
   // visible.
   void SetExtensionState(const std::string& ext_id, bool is_enabled);
 
   // Adds |observer|. This method should only be called on the UI thread.
   void AddObserver(Observer* observer);
 
   // Remove |observer|. This method should only be called on the UI thread.
   void RemoveObserver(Observer* observer);
 
  private:
+  friend class base::RefCountedThreadSafe<ExtensionContentSettingsStore>;
+
   struct ExtensionEntry;
   struct ContentSettingSpec {
     ContentSettingSpec(const ContentSettingsPattern& primary_pattern,
                        const ContentSettingsPattern& secondary_pattern,
                        ContentSettingsType type,
                        const content_settings::ResourceIdentifier& identifier,
                        ContentSetting setting);
 
     ContentSettingsPattern primary_pattern;
     ContentSettingsPattern secondary_pattern;
     ContentSettingsType content_type;
     content_settings::ResourceIdentifier resource_identifier;
     ContentSetting setting;
   };
 
   typedef std::map<std::string, ExtensionEntry*> ExtensionEntryMap;
 
   typedef std::list<ContentSettingSpec> ContentSettingSpecList;
 
+  virtual ~ExtensionContentSettingsStore();
+
   ContentSetting GetContentSettingFromSpecList(
       const GURL& embedded_url,
       const GURL& top_level_url,
       ContentSettingsType type,
       const content_settings::ResourceIdentifier& identifier,
       const ContentSettingSpecList& setting_spec_list) const;
 
   ContentSettingSpecList* GetContentSettingSpecList(
       const std::string& ext_id,
       ExtensionPrefsScope scope);
 
   const ContentSettingSpecList* GetContentSettingSpecList(
       const std::string& ext_id,
       ExtensionPrefsScope scope) const;
 
   // Adds all content setting rules for |type| and |identifier| found in
   // |setting_spec_list| to |rules|.
   static void AddRules(ContentSettingsType type,
                        const content_settings::ResourceIdentifier& identifier,
                        const ContentSettingSpecList* setting_spec_list,
                        content_settings::ProviderInterface::Rules* rules);
 
   void NotifyOfContentSettingChanged(const std::string& extension_id,
                                      bool incognito);
 
-  void NotifyOfDestruction();
-
   bool OnCorrectThread();
 
   ExtensionEntryMap entries_;
 
   ObserverList<Observer, false> observers_;
 
   mutable base::Lock lock_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionContentSettingsStore);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_CONTENT_SETTINGS_STORE_H_