Simplify the shutdown sequence of Oilpan's heap

third_party/WebKit/Source/platform/heap/Heap.h

 /*
  * 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 90 matching lines @@
         static_assert(sizeof(T), "T must be fully defined");
         return object->isHeapObjectAlive();
     }
 };
 
 class PLATFORM_EXPORT Heap {
     STATIC_ONLY(Heap);
 public:
     static void init();
     static void shutdown();
-    static void doShutdown();
 
     static CrossThreadPersistentRegion& crossThreadPersistentRegion();
 
 #if ENABLE(ASSERT)
     static BasePage* findPageFromAddress(Address);
     static BasePage* findPageFromAddress(const void* pointer) { return findPageFromAddress(reinterpret_cast<Address>(const_cast<void*>(pointer))); }
 #endif
 
     template<typename T>
     static inline bool isHeapObjectAlive(T* object)
@@ skipping 410 matching lines @@
 void VisitorHelper<Derived>::handleWeakCell(Visitor* self, void* object)
 {
     T** cell = reinterpret_cast<T**>(object);
     if (*cell && !ObjectAliveTrait<T>::isHeapObjectAlive(*cell))
         *cell = nullptr;
 }
 
 } // namespace blink
 
 #endif // Heap_h