Revert of Simplify the shutdown sequence of Oilpan's heap

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

Index: third_party/WebKit/Source/platform/heap/Heap.cpp
diff --git a/third_party/WebKit/Source/platform/heap/Heap.cpp b/third_party/WebKit/Source/platform/heap/Heap.cpp
index d676331908191215109d75c322f67f0ee5688d57..69cbac7e9dff8c35817455a37765f05a7c1e92fc 100644
--- a/third_party/WebKit/Source/platform/heap/Heap.cpp
+++ b/third_party/WebKit/Source/platform/heap/Heap.cpp
@@ -138,14 +138,19 @@
 
 void Heap::shutdown()
 {
-    ASSERT(s_markingStack);
-
     if (Platform::current() && Platform::current()->currentThread())
         Platform::current()->unregisterMemoryDumpProvider(BlinkGCMemoryDumpProvider::instance());
-
-    // The main thread must be the last thread that gets detached.
-    RELEASE_ASSERT(ThreadState::attachedThreads().size() == 0);
-
+    s_shutdownCalled = true;
+    ThreadState::shutdownHeapIfNecessary();
+}
+
+void Heap::doShutdown()
+{
+    // We don't want to call doShutdown() twice.
+    if (!s_markingStack)
+        return;
+
+    ASSERT(!ThreadState::attachedThreads().size());
     delete s_heapDoesNotContainCache;
     s_heapDoesNotContainCache = nullptr;
     delete s_freePagePool;