[Sync] Avoid unregistering object IDs on shutdown

chrome/browser/sync/glue/bridged_sync_notifier.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_SYNC_GLUE_BRIDGED_SYNC_NOTIFIER_H_
 #define CHROME_BROWSER_SYNC_GLUE_BRIDGED_SYNC_NOTIFIER_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "sync/notifier/sync_notifier.h"
@@ skipping 10 matching lines @@
 // ChromeSyncNotificationBridge.
 class BridgedSyncNotifier : public syncer::SyncNotifier {
  public:
   // Does not take ownership of |bridge|. Takes ownership of |delegate|.
   // |delegate| may be NULL.
   BridgedSyncNotifier(ChromeSyncNotificationBridge* bridge,
                       syncer::SyncNotifier* delegate);
   virtual ~BridgedSyncNotifier();
 
   // SyncNotifier implementation. Passes through all calls to the delegate.
-  // UpdateRegisteredIds calls will also be forwarded to the bridge.
+  // RegisterHandler, UnregisterHandler, and UpdateRegisteredIds calls will
+  // also be forwarded to the bridge.
+  virtual void RegisterHandler(syncer::SyncNotifierObserver* handler) OVERRIDE;
   virtual void UpdateRegisteredIds(syncer::SyncNotifierObserver* handler,
                                    const syncer::ObjectIdSet& ids) OVERRIDE;
+  virtual void UnregisterHandler(
+      syncer::SyncNotifierObserver* handler) OVERRIDE;
   virtual void SetUniqueId(const std::string& unique_id) OVERRIDE;
   virtual void SetStateDeprecated(const std::string& state) OVERRIDE;
   virtual void UpdateCredentials(
       const std::string& email, const std::string& token) OVERRIDE;
   virtual void SendNotification(
       syncer::ModelTypeSet changed_types) OVERRIDE;
 
  private:
   // The notification bridge that we register the observers with.
   ChromeSyncNotificationBridge* bridge_;
 
   // The delegate we are wrapping.
   scoped_ptr<syncer::SyncNotifier> delegate_;
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_BRIDGED_SYNC_NOTIFIER_H_