REGRESSION(r171966): Custom elements in async imports don't get upgrade.

Source/core/dom/custom/CustomElementMicrotaskQueue.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 65 matching lines @@
 #endif
 
 void CustomElementMicrotaskQueue::enqueue(PassOwnPtr<CustomElementMicrotaskStep> step)
 {
     m_queue.append(step);
 }
 
 CustomElementMicrotaskStep::Result CustomElementMicrotaskQueue::dispatch()
 {
     MicrotaskQueueInvocationScope scope(this);
-    Result result = Result(0);
+    Vector<OwnPtr<CustomElementMicrotaskStep> > remaining;

[dominicc (has gone to gerrit), 2014/04/30 23:57:20]

I think you should avoid this "remain" thing. It just exists to delay onload,
right? Storing this state in here obfuscates that; it belongs on the import.
When the CustomElementMicrotaskQueue exits it should notify the import and let
the import do the coordination.

+    Result accumulatedResult = Result(CustomElementMicrotaskStep::Continue);
 
     unsigned i;
     for (i = 0; i < m_queue.size(); ++i) {
-        result = Result(result | m_queue[i]->process());
+        Result result = m_queue[i]->process();
+        accumulatedResult = Result(result | accumulatedResult);
 
-        if (result & CustomElementMicrotaskStep::ShouldStop)
+        bool shouldStop = result & CustomElementMicrotaskStep::ShouldStop;
+        bool shouldRemain = result & CustomElementMicrotaskStep::ShouldRemain;
+        ASSERT(!shouldStop || shouldStop == shouldRemain);
+        if (shouldRemain)
+            remaining.append(m_queue[i].release());
+        if (shouldStop)
             break;
     }
 
-    bool wasStopped = i < m_queue.size();
-    if (wasStopped)
-        m_queue.remove(0, i);
-    else
-        m_queue.resize(0);
-
-    return result;
+    for (++i; i < m_queue.size(); ++i)
+        remaining.append(m_queue[i].release());
+    m_queue.swap(remaining);
+    return accumulatedResult;
 }
 
+#if !defined(NDEBUG)
+void CustomElementMicrotaskQueue::show(unsigned indent)
+{
+    for (unsigned i = 0; i < m_queue.size(); ++i) {
+        if (m_queue[i]) {
+            m_queue[i]->show(indent);
+        } else {
+            for (unsigned j = 0; j < indent; ++j)
+                fprintf(stderr, " ");
+            fprintf(stderr, "null\n");
+        }
+    }
+}
+#endif
+
 } // namespace WebCore