Add onChanged events to the extension settings API, both from sync and between

chrome/browser/extensions/syncable_extension_settings_storage.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_SYNCABLE_EXTENSION_SETTINGS_STORAGE_H_
 #define CHROME_BROWSER_EXTENSIONS_SYNCABLE_EXTENSION_SETTINGS_STORAGE_H_
 #pragma once
 
 #include "base/compiler_specific.h"
 #include "base/memory/weak_ptr.h"
+#include "base/observer_list_threadsafe.h"
 #include "base/values.h"
+#include "chrome/browser/extensions/extension_settings_observer.h"
 #include "chrome/browser/extensions/extension_settings_storage.h"
 #include "chrome/browser/extensions/extension_setting_sync_data.h"
 #include "chrome/browser/sync/api/syncable_service.h"
 #include "chrome/browser/sync/api/sync_change.h"
 
 // Decorates an ExtensionSettingsStorage with sync behaviour.
 class SyncableExtensionSettingsStorage : public ExtensionSettingsStorage {
  public:
   explicit SyncableExtensionSettingsStorage(
+      // Reference taken.
+      ObserverListThreadSafe<ExtensionSettingsObserver>* observers,

[akalin, 2011/10/07 21:06:23]

const ref to scoped_ptr

[not at google - send to devlin, 2011/10/10 01:00:16]

Done.

       std::string extension_id,

[akalin, 2011/10/07 21:06:23]

const ref to string

[not at google - send to devlin, 2011/10/10 01:00:16]

Done.

       // Ownership taken.
       ExtensionSettingsStorage* delegate);
 
   virtual ~SyncableExtensionSettingsStorage();
 
   // ExtensionSettingsStorage implementation.
   virtual Result Get(const std::string& key) OVERRIDE;
   virtual Result Get(const std::vector<std::string>& keys) OVERRIDE;
   virtual Result Get() OVERRIDE;
   virtual Result Set(const std::string& key, const Value& value) OVERRIDE;
@@ skipping 23 matching lines @@
   void SendDeletesToSync(const std::set<std::string>& keys);
 
   // Sends all local settings to sync (synced settings assumed to be empty).
   SyncError SendLocalSettingsToSync(
       const DictionaryValue& settings);
 
   // Overwrites local state with sync state.
   SyncError OverwriteLocalSettingsWithSync(
       const DictionaryValue& sync_state, const DictionaryValue& settings);
 
+  // List of observers to settings changes.
+  scoped_refptr<ObserverListThreadSafe<ExtensionSettingsObserver> > observers_;
+
   // Id of the extension these settings are for.
   std::string const extension_id_;
 
   // Storage area to sync.
   const scoped_ptr<ExtensionSettingsStorage> delegate_;
 
   // Sync processor.  Non-NULL while sync is enabled (between calls to
   // StartSyncing and StopSyncing).
   SyncChangeProcessor* sync_processor_;
 
   // Keys of the settings that are currently being synced.
   std::set<std::string> synced_keys_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncableExtensionSettingsStorage);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_SYNCABLE_EXTENSION_SETTINGS_STORAGE_H_