[oilpan]: Make thread shutdown more robust.

Source/platform/heap/HeapTest.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 1679 matching lines @@
     Heap::collectGarbage(ThreadState::NoHeapPointersOnStack);
     EXPECT_EQ(2, HeapTestSubClass::s_destructorCalls);
     EXPECT_EQ(3, HeapTestSuperClass::s_destructorCalls);
 }
 
 TEST(HeapTest, TypedHeapSanity)
 {
     // We use TraceCounter for allocating an object on the general heap.
     Persistent<TraceCounter> generalHeapObject = TraceCounter::create();
     Persistent<TestTypedHeapClass> typedHeapObject = TestTypedHeapClass::create();
-    EXPECT_NE(pageHeaderAddress(reinterpret_cast<Address>(generalHeapObject.get())),
-        pageHeaderAddress(reinterpret_cast<Address>(typedHeapObject.get())));
+    EXPECT_NE(pageHeaderFromObject(generalHeapObject.get()),
+        pageHeaderFromObject(typedHeapObject.get()));
 }
 
 TEST(HeapTest, NoAllocation)
 {
     EXPECT_TRUE(ThreadState::current()->isAllocationAllowed());
     {
         // Disallow allocation
         NoAllocationScope<AnyThread> noAllocationScope;
         EXPECT_FALSE(ThreadState::current()->isAllocationAllowed());
     }
@@ skipping 2866 matching lines @@
     Heap::collectGarbage(ThreadState::NoHeapPointersOnStack);
     EXPECT_EQ(1u, map->size());
     EXPECT_EQ(lifeObject, map->get(lifeObject)->link());
     lifeObject.clear(); // Despite its name.
     Heap::collectGarbage(ThreadState::NoHeapPointersOnStack);
     EXPECT_EQ(0u, map->size());
 }
 
 
 } // WebCore namespace