InlinedVisitor: Migrate dom to use inlined tracing

Source/core/dom/custom/CustomElementMicrotaskImportStep.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 69 matching lines @@
 CustomElementMicrotaskStep::Result CustomElementMicrotaskImportStep::process()
 {
     m_queue->dispatch();
     if (!m_queue->isEmpty() || shouldWaitForImport())
         return Processing;
 
     didUpgradeAllCustomElements();
     return FinishedProcessing;
 }
 
-void CustomElementMicrotaskImportStep::trace(Visitor* visitor)
+DEFINE_TRACE(CustomElementMicrotaskImportStep)
 {
     visitor->trace(m_import);
     visitor->trace(m_queue);
     CustomElementMicrotaskStep::trace(visitor);
 }
 
 #if !defined(NDEBUG)
 void CustomElementMicrotaskImportStep::show(unsigned indent)
 {
     fprintf(stderr, "%*sImport(wait=%d sync=%d, url=%s)\n", indent, "", shouldWaitForImport(), m_import && m_import->isSync(), m_import ? m_import->url().string().utf8().data() : "null");
     m_queue->show(indent + 1);
 }
 #endif
 
 } // namespace blink