HTML Imports: Fix race conditions on HTMLImportsChild

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 67 matching lines @@
     if (!(result & ShouldStop) && !shouldWaitForImport())
         didUpgradeAllCustomElements();
 
     if (shouldWaitForImport())
         result = Result(result | ShouldRemain | ShouldStop);
     if (!shouldStopProcessing())
         result = Result(result & ~ShouldStop);
     return result;
 }
 
+bool CustomElementMicrotaskImportStep::needsProcessOrStop() const
+{
+    return shouldStopProcessing() || m_queue->needsProcessOrStop();
+}
+
 #if !defined(NDEBUG)
 void CustomElementMicrotaskImportStep::show(unsigned indent)
 {
     fprintf(stderr, "%*sImport(wait=%d sync=%d, url=%s)\n", indent, "", shouldWaitForImport(), shouldStopProcessing(), m_import ? m_import->url().string().utf8().data() : "null");
     m_queue->show(indent + 1);
 }
 #endif
 
 } // namespace WebCore