Cheaper thread-safe atomic initialization of static references.

Source/modules/webdatabase/QuotaTracker.cpp

 /*
  * Copyright (C) 2011 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 21 matching lines @@
 #include "modules/webdatabase/QuotaTracker.h"
 
 #include "public/platform/Platform.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/Threading.h"
 
 namespace blink {
 
 QuotaTracker& QuotaTracker::instance()
 {
-    AtomicallyInitializedStatic(QuotaTracker&, tracker = *new QuotaTracker);
+    AtomicallyInitializedStaticReference(QuotaTracker, tracker, new QuotaTracker);
     return tracker;
 }
 
 void QuotaTracker::getDatabaseSizeAndSpaceAvailableToOrigin(
     const String& originIdentifier, const String& databaseName,
     unsigned long long* databaseSize, unsigned long long* spaceAvailable)
 {
     // Extra scope to unlock prior to potentially calling Platform.
     {
         MutexLocker lockData(m_dataGuard);
@@ skipping 27 matching lines @@
     m_spaceAvailableToOrigins.set(originIdentifier, spaceAvailable);
 }
 
 void QuotaTracker::resetSpaceAvailableToOrigin(const String& originIdentifier)
 {
     MutexLocker lockData(m_dataGuard);
     m_spaceAvailableToOrigins.remove(originIdentifier);
 }
 
 } // namespace blink