Oilpan: DOM wrappers don't need to keep persistent handles

Source/platform/heap/ThreadState.h

Index: Source/platform/heap/ThreadState.h
diff --git a/Source/platform/heap/ThreadState.h b/Source/platform/heap/ThreadState.h
index 54e561338f10ccdbeae0478031f2e27c7411f688..96b0a23c17b5c92a278d34738dd0b80a07159e62 100644
--- a/Source/platform/heap/ThreadState.h
+++ b/Source/platform/heap/ThreadState.h
@@ -52,7 +52,6 @@ struct GCInfo;
 class HeapObjectHeader;
 class PageMemory;
 class PersistentNode;
-class WrapperPersistentRegion;
 class Visitor;
 class SafePointBarrier;
 class SafePointAwareMutexLocker;
@@ -598,14 +597,6 @@ public:
     BaseHeapPage* contains(void* pointer) { return contains(reinterpret_cast<Address>(pointer)); }
     BaseHeapPage* contains(const void* pointer) { return contains(const_cast<void*>(pointer)); }
 
-    WrapperPersistentRegion* wrapperRoots() const
-    {
-        ASSERT(m_liveWrapperPersistents);
-        return m_liveWrapperPersistents;
-    }
-    WrapperPersistentRegion* takeWrapperPersistentRegion();
-    void freeWrapperPersistentRegion(WrapperPersistentRegion*);
-
     // List of persistent roots allocated on the given thread.
     PersistentNode* roots() const { return m_persistents.get(); }
 
@@ -699,6 +690,11 @@ public:
 
     void shouldFlushHeapDoesNotContainCache() { m_shouldFlushHeapDoesNotContainCache = true; }
 
+    void registerTraceDOMWrappers(void (*traceDOMWrappers)(Visitor*))
+    {
+        m_traceDOMWrappers = traceDOMWrappers;
+    }
+
 private:
     explicit ThreadState();
     ~ThreadState();
@@ -756,9 +752,6 @@ private:
     static uint8_t s_mainThreadStateStorage[];
 
     ThreadIdentifier m_thread;
-    WrapperPersistentRegion* m_liveWrapperPersistents;
-    WrapperPersistentRegion* m_pooledWrapperPersistents;
-    size_t m_pooledWrapperPersistentRegionCount;
     OwnPtr<PersistentNode> m_persistents;
     StackState m_stackState;
     intptr_t* m_startOfStack;
@@ -791,6 +784,8 @@ private:
     CallbackStack* m_weakCallbackStack;
     HashMap<void*, bool (*)(void*, Visitor&)> m_preFinalizers;
 
+    void (*m_traceDOMWrappers)(Visitor*);
+
 #if defined(ADDRESS_SANITIZER)
     void* m_asanFakeStack;
 #endif