[Sync] InvalidationService shouldn't CHECK when registering ObjectId for more than one handler

components/invalidation/ticl_invalidation_service.h

 // Copyright 2014 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 COMPONENTS_INVALIDATION_TICL_INVALIDATION_SERVICE_H_
 #define COMPONENTS_INVALIDATION_TICL_INVALIDATION_SERVICE_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 56 matching lines @@
       const scoped_refptr<net::URLRequestContextGetter>& request_context);
   ~TiclInvalidationService() override;
 
   void Init(
       scoped_ptr<syncer::InvalidationStateTracker> invalidation_state_tracker);
 
   // InvalidationService implementation.
   // It is an error to have registered handlers when the service is destroyed.
   void RegisterInvalidationHandler(
       syncer::InvalidationHandler* handler) override;
-  void UpdateRegisteredInvalidationIds(syncer::InvalidationHandler* handler,
+  bool UpdateRegisteredInvalidationIds(syncer::InvalidationHandler* handler,
                                        const syncer::ObjectIdSet& ids) override;
   void UnregisterInvalidationHandler(
       syncer::InvalidationHandler* handler) override;
   syncer::InvalidatorState GetInvalidatorState() const override;
   std::string GetInvalidatorClientId() const override;
   InvalidationLogger* GetInvalidationLogger() override;
   void RequestDetailedStatus(
       base::Callback<void(const base::DictionaryValue&)> caller) const override;
   IdentityProvider* GetIdentityProvider() override;
 
@@ skipping 71 matching lines @@
   // Keep a copy of the important parameters used in network channel creation
   // for debugging.
   base::DictionaryValue network_channel_options_;
 
   DISALLOW_COPY_AND_ASSIGN(TiclInvalidationService);
 };
 
 }  // namespace invalidation
 
 #endif  // COMPONENTS_INVALIDATION_TICL_INVALIDATION_SERVICE_H_