Cheaper thread-safe atomic initialization of static references.

Source/platform/heap/Heap.cpp

 /*
  * Copyright (C) 2013 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 1973 matching lines @@
         fprintf(stderr, "\n");
     }
 
     static void dumpPathToObjectOnNextGC(void* p)
     {
         objectsToFindPath().add(reinterpret_cast<uintptr_t>(p));
     }
 
     static Mutex& objectGraphMutex()
     {
-        AtomicallyInitializedStatic(Mutex&, mutex = *new Mutex);
+        AtomicallyInitializedStaticReference(Mutex, mutex, new Mutex);
         return mutex;
     }
 
     static LiveObjectMap& previouslyLive()
     {
         DEFINE_STATIC_LOCAL(LiveObjectMap, map, ());
         return map;
     }
 
     static LiveObjectMap& currentlyLive()
@@ skipping 614 matching lines @@
         return nullptr;
     if (PageMemoryRegion* region = s_regionTree->lookup(address)) {
         BaseHeapPage* page = region->pageFromAddress(address);
         return page && !page->orphaned() ? page : nullptr;
     }
     return nullptr;
 }
 
 static Mutex& regionTreeMutex()
 {
-    AtomicallyInitializedStatic(Mutex&, mutex = *new Mutex);
+    AtomicallyInitializedStaticReference(Mutex, mutex, new Mutex);
     return mutex;
 }
 
 void Heap::removePageMemoryRegion(PageMemoryRegion* region)
 {
     // Deletion of large objects (and thus their regions) can happen
     // concurrently on sweeper threads.  Removal can also happen during thread
     // shutdown, but that case is safe.  Regardless, we make all removals
     // mutually exclusive.
     MutexLocker locker(regionTreeMutex());
@@ skipping 72 matching lines @@
 bool Heap::s_shutdownCalled = false;
 bool Heap::s_lastGCWasConservative = false;
 FreePagePool* Heap::s_freePagePool;
 OrphanedPagePool* Heap::s_orphanedPagePool;
 Heap::RegionTree* Heap::s_regionTree = nullptr;
 size_t Heap::s_allocatedObjectSize = 0;
 size_t Heap::s_allocatedSpace = 0;
 size_t Heap::s_markedObjectSize = 0;
 
 } // namespace blink