Cheaper thread-safe atomic initialization of static references.

Source/core/timing/Performance.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel 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.
@@ skipping 144 matching lines @@
 
 void Performance::webkitSetResourceTimingBufferSize(unsigned size)
 {
     m_resourceTimingBufferSize = size;
     if (isResourceTimingBufferFull())
         dispatchEvent(Event::create(EventTypeNames::webkitresourcetimingbufferfull));
 }
 
 static bool passesTimingAllowCheck(const ResourceResponse& response, Document* requestingDocument, const AtomicString& originalTimingAllowOrigin)
 {
-    AtomicallyInitializedStatic(AtomicString&, timingAllowOrigin = *new AtomicString("timing-allow-origin"));
+    AtomicallyInitializedStaticReference(AtomicString, timingAllowOrigin, new AtomicString("timing-allow-origin"));
 
     RefPtr<SecurityOrigin> resourceOrigin = SecurityOrigin::create(response.url());
     if (resourceOrigin->isSameSchemeHostPort(requestingDocument->securityOrigin()))
         return true;
 
     const AtomicString& timingAllowOriginString = originalTimingAllowOrigin.isEmpty() ? response.httpHeaderField(timingAllowOrigin) : originalTimingAllowOrigin;
     if (timingAllowOriginString.isEmpty() || equalIgnoringCase(timingAllowOriginString, "null"))
         return false;
 
     if (timingAllowOriginString == starAtom)
@@ skipping 106 matching lines @@
 {
     visitor->trace(m_navigation);
     visitor->trace(m_timing);
     visitor->trace(m_resourceTimingBuffer);
     visitor->trace(m_userTiming);
     EventTargetWithInlineData::trace(visitor);
     DOMWindowProperty::trace(visitor);
 }
 
 } // namespace blink