[Sync] Rename csync namespace to syncer

sync/notifier/invalidation_util.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.
 //
 // Various utilities for dealing with invalidation data types.
 
 #ifndef SYNC_NOTIFIER_INVALIDATION_UTIL_H_
 #define SYNC_NOTIFIER_INVALIDATION_UTIL_H_
 #pragma once
 
 #include <string>
 
 #include "sync/internal_api/public/syncable/model_type.h"
 
 namespace invalidation {
 
 class Invalidation;
 class ObjectId;
 
 }  // namespace invalidation
 
-namespace csync {
+namespace syncer {
 
 struct ObjectIdLessThan {
   bool operator()(const invalidation::ObjectId& lhs,
                   const invalidation::ObjectId& rhs) const;
 };
 
 bool RealModelTypeToObjectId(syncable::ModelType model_type,
                              invalidation::ObjectId* object_id);
 
 bool ObjectIdToRealModelType(const invalidation::ObjectId& object_id,
                              syncable::ModelType* model_type);
 
 std::string ObjectIdToString(const invalidation::ObjectId& object_id);
 
 std::string InvalidationToString(
     const invalidation::Invalidation& invalidation);
 
-}  // namespace csync
+}  // namespace syncer
 
 #endif  // SYNC_NOTIFIER_INVALIDATION_UTIL_H_