Simplify the shutdown sequence of Oilpan's heap

third_party/WebKit/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 120 matching lines @@
 #endif
 
     GCInfoTable::init();
 
     if (Platform::current() && Platform::current()->currentThread())
         Platform::current()->registerMemoryDumpProvider(BlinkGCMemoryDumpProvider::instance(), "BlinkGC");
 }
 
 void Heap::shutdown()
 {
+    ASSERT(s_markingStack);
+
     if (Platform::current() && Platform::current()->currentThread())
         Platform::current()->unregisterMemoryDumpProvider(BlinkGCMemoryDumpProvider::instance());
-    s_shutdownCalled = true;
-    ThreadState::shutdownHeapIfNecessary();
-}
 
-void Heap::doShutdown()
-{
-    // We don't want to call doShutdown() twice.
-    if (!s_markingStack)
-        return;
+    // The main thread must be the last thread that gets detached.
+    RELEASE_ASSERT(ThreadState::attachedThreads().size() == 0);
 
-    ASSERT(!ThreadState::attachedThreads().size());
     delete s_heapDoesNotContainCache;
     s_heapDoesNotContainCache = nullptr;
     delete s_freePagePool;
     s_freePagePool = nullptr;
     delete s_orphanedPagePool;
     s_orphanedPagePool = nullptr;
     delete s_globalWeakCallbackStack;
     s_globalWeakCallbackStack = nullptr;
     delete s_postMarkingCallbackStack;
     s_postMarkingCallbackStack = nullptr;
@@ skipping 524 matching lines @@
 size_t Heap::s_wrapperCountAtLastGC = 0;
 size_t Heap::s_collectedWrapperCount = 0;
 size_t Heap::s_partitionAllocSizeAtLastGC = 0;
 double Heap::s_estimatedMarkingTimePerByte = 0.0;
 bool Heap::s_isLowEndDevice = false;
 #if ENABLE(ASSERT)
 uint16_t Heap::s_gcGeneration = 0;
 #endif
 
 } // namespace blink