Create & use microtask work queue

Source/bindings/v8/V8PerIsolateData.h

 /*
  * Copyright (C) 2009 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 86 matching lines @@
     }
 
     // DOMDataStore is owned outside V8PerIsolateData.
     DOMDataStore* workerDOMDataStore() { return m_workerDomDataStore; }
     void setWorkerDOMDataStore(DOMDataStore* store) { m_workerDomDataStore = store; }
 
     int recursionLevel() const { return m_recursionLevel; }
     int incrementRecursionLevel() { return ++m_recursionLevel; }
     int decrementRecursionLevel() { return --m_recursionLevel; }
 
+    bool performingMicrotaskCheckpoint() const { return m_performingMicrotaskCheckpoint; }
+    void setPerformingMicrotaskCheckpoint(bool performingMicrotaskCheckpoint) { m_performingMicrotaskCheckpoint = performingMicrotaskCheckpoint; }
+
 #ifndef NDEBUG
     int internalScriptRecursionLevel() const { return m_internalScriptRecursionLevel; }
     int incrementInternalScriptRecursionLevel() { return ++m_internalScriptRecursionLevel; }
     int decrementInternalScriptRecursionLevel() { return --m_internalScriptRecursionLevel; }
 #endif
 
     GCEventData* gcEventData() { return m_gcEventData.get(); }
 
     // Gives the system a hint that we should request garbage collection
     // upon the next close or navigation event, because some expensive
@@ skipping 39 matching lines @@
     bool m_constructorMode;
     friend class ConstructorMode;
 
     int m_recursionLevel;
 
 #ifndef NDEBUG
     int m_internalScriptRecursionLevel;
 #endif
     OwnPtr<GCEventData> m_gcEventData;
     bool m_shouldCollectGarbageSoon;
+    bool m_performingMicrotaskCheckpoint;
 };
 
 } // namespace WebCore
 
 #endif // V8PerIsolateData_h