[WIP] Custom element upgrades

third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.cpp

 // Copyright 2016 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 "core/dom/custom/CustomElementDefinition.h"
 
 namespace blink {
 
 CustomElementDefinition::CustomElementDefinition(
     const CustomElementDescriptor& descriptor)
     : m_descriptor(descriptor)
 {
 }
 
 CustomElementDefinition::~CustomElementDefinition()
 {
 }
 
+DEFINE_TRACE(CustomElementDefinition)
+{
+    visitor->trace(m_constructionStack);
+}
+
 } // namespace blink