Cheaper thread-safe atomic initialization of static references.

Source/core/timing/MemoryInfo.cpp

 /*
  * Copyright (C) 2010 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 40 matching lines @@
     }
 
     void getCachedHeapSize(HeapInfo& info)
     {
         maybeUpdate();
         info = m_info;
     }
 
     static HeapSizeCache& forCurrentThread()
     {
-        AtomicallyInitializedStatic(ThreadSpecific<HeapSizeCache>*, heapSizeCache = new ThreadSpecific<HeapSizeCache>);
-        return **heapSizeCache;
+        AtomicallyInitializedStaticReference(ThreadSpecific<HeapSizeCache>, heapSizeCache, new ThreadSpecific<HeapSizeCache>);
+        return *heapSizeCache;
     }
 
 private:
     void maybeUpdate()
     {
         // We rate-limit queries to once every twenty minutes to make it more difficult
         // for attackers to compare memory usage before and after some event.
         const double TwentyMinutesInSeconds = 20 * 60;
 
         double now = monotonicallyIncreasingTime();
@@ skipping 66 matching lines @@
 
 MemoryInfo::MemoryInfo()
 {
     if (RuntimeEnabledFeatures::preciseMemoryInfoEnabled())
         ScriptGCEvent::getHeapSize(m_info);
     else
         HeapSizeCache::forCurrentThread().getCachedHeapSize(m_info);
 }
 
 } // namespace blink