Cheaper thread-safe atomic initialization of static references.

Source/core/events/EventTarget.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  *           (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ skipping 363 matching lines @@
         // To match Mozilla, the AT_TARGET phase fires both capturing and bubbling
         // event listeners, even though that violates some versions of the DOM spec.
         registeredListener.listener->handleEvent(context, event);
         InspectorInstrumentation::didHandleEvent(cookie);
     }
     d->firingEventIterators->removeLast();
 }
 
 const EventListenerVector& EventTarget::getEventListeners(const AtomicString& eventType)
 {
-    AtomicallyInitializedStatic(EventListenerVector*, emptyVector = new EventListenerVector);
+    AtomicallyInitializedStaticReference(EventListenerVector, emptyVector, new EventListenerVector);
 
     EventTargetData* d = eventTargetData();
     if (!d)
-        return *emptyVector;
+        return emptyVector;
 
     EventListenerVector* listenerVector = d->eventListenerMap.find(eventType);
     if (!listenerVector)
-        return *emptyVector;
+        return emptyVector;
 
     return *listenerVector;
 }
 
 Vector<AtomicString> EventTarget::eventTypes()
 {
     EventTargetData* d = eventTargetData();
     return d ? d->eventListenerMap.eventTypes() : Vector<AtomicString>();
 }
 
 void EventTarget::removeAllEventListeners()
 {
     EventTargetData* d = eventTargetData();
     if (!d)
         return;
     d->eventListenerMap.clear();
 
     // Notify firing events planning to invoke the listener at 'index' that
     // they have one less listener to invoke.
     if (d->firingEventIterators) {
         for (size_t i = 0; i < d->firingEventIterators->size(); ++i) {
             d->firingEventIterators->at(i).iterator = 0;
             d->firingEventIterators->at(i).end = 0;
         }
     }
 }
 
 } // namespace blink