InlinedVisitor: Migrate html to use inlined tracing

Source/core/html/imports/HTMLImportChild.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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 203 matching lines @@
     HTMLImport::showThis();
     fprintf(stderr, " loader=%p first=%d, step=%p sync=%s url=%s",
         m_loader.get(),
         isFirst,
         m_customElementMicrotaskStep.get(),
         isSync() ? "Y" : "N",
         url().string().utf8().data());
 }
 #endif
 
-void HTMLImportChild::trace(Visitor* visitor)
+DEFINE_TRACE(HTMLImportChild)
 {
     visitor->trace(m_customElementMicrotaskStep);
     visitor->trace(m_loader);
     visitor->trace(m_client);
     HTMLImport::trace(visitor);
 }
 
 } // namespace blink