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

chrome/browser/policy/cloud/cloud_policy_invalidator.h

 // Copyright 2013 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_POLICY_CLOUD_CLOUD_POLICY_INVALIDATOR_H_
 #define CHROME_BROWSER_POLICY_CLOUD_CLOUD_POLICY_INVALIDATOR_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
+#include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
 #include "components/invalidation/invalidation.h"
 #include "components/invalidation/invalidation_handler.h"
 #include "components/policy/core/common/cloud/cloud_policy_core.h"
 #include "components/policy/core/common/cloud/cloud_policy_store.h"
 #include "google/cacheinvalidation/include/types.h"
 #include "policy/proto/device_management_backend.pb.h"
@@ skipping 215 matching lines @@
 
   // WeakPtrFactory used to create callbacks to this object.
   base::WeakPtrFactory<CloudPolicyInvalidator> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CloudPolicyInvalidator);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_POLICY_CLOUD_CLOUD_POLICY_INVALIDATOR_H_