[Sync] Move sync/{internal_api,syncable} into syncer namespace

sync/test/null_directory_change_delegate.cc

 // 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.
 
 #include "sync/test/null_directory_change_delegate.h"
 
+namespace syncer {
 namespace syncable {
 
 NullDirectoryChangeDelegate::~NullDirectoryChangeDelegate() {}
 
 void NullDirectoryChangeDelegate::HandleCalculateChangesChangeEventFromSyncApi(
     const ImmutableWriteTransactionInfo& write_transaction_info,
     BaseTransaction* trans) {}
 
 void NullDirectoryChangeDelegate::HandleCalculateChangesChangeEventFromSyncer(
     const ImmutableWriteTransactionInfo& write_transaction_info,
     BaseTransaction* trans) {}
 
 ModelTypeSet
     NullDirectoryChangeDelegate::HandleTransactionEndingChangeEvent(
         const ImmutableWriteTransactionInfo& write_transaction_info,
         BaseTransaction* trans) {
   return ModelTypeSet();
 }
 
 void NullDirectoryChangeDelegate::HandleTransactionCompleteChangeEvent(
     ModelTypeSet models_with_changes) {}
 
 }  // namespace syncable
+}  // namespace syncer