[Sync] Replacing NULL with nullptr in code and null in comments for components/sync/

components/sync/test/fake_server/bookmark_entity_builder.cc

 // 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.
 
 #include "components/sync/test/fake_server/bookmark_entity_builder.h"
 
 #include <stdint.h>
 
 #include "base/guid.h"
 #include "base/memory/ptr_util.h"
@@ skipping 29 matching lines @@
 
 BookmarkEntityBuilder::~BookmarkEntityBuilder() {}
 
 void BookmarkEntityBuilder::SetParentId(const std::string& parent_id) {
   parent_id_ = parent_id;
 }
 
 std::unique_ptr<FakeServerEntity> BookmarkEntityBuilder::BuildBookmark(
     const GURL& url) {
   if (!url.is_valid()) {
-    return base::WrapUnique<FakeServerEntity>(NULL);
+    return base::WrapUnique<FakeServerEntity>(nullptr);
   }
 
   sync_pb::EntitySpecifics entity_specifics = CreateBaseEntitySpecifics();
   entity_specifics.mutable_bookmark()->set_url(url.spec());
   const bool kIsNotFolder = false;
   return Build(entity_specifics, kIsNotFolder);
 }
 
 std::unique_ptr<FakeServerEntity> BookmarkEntityBuilder::BuildFolder() {
   const bool kIsFolder = true;
@@ skipping 26 matching lines @@
   const string id =
       FakeServerEntity::CreateId(syncer::BOOKMARKS, base::GenerateGUID());
 
   return base::WrapUnique<FakeServerEntity>(new BookmarkEntity(
       id, kUnusedVersion, title_, originator_cache_guid_,
       originator_client_item_id_, unique_position, entity_specifics, is_folder,
       parent_id_, kDefaultTime, kDefaultTime));
 }
 
 }  // namespace fake_server