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diff --git a/WebCore/bindings/v8/V8DOMMap.cpp b/WebCore/bindings/v8/V8DOMMap.cpp
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+++ b/WebCore/bindings/v8/V8DOMMap.cpp
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+/*
+ * Copyright (C) 2009 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
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "V8DOMMap.h"
+
+#include "DOMObjectsInclude.h"
+
+#include <v8.h>
+#include <wtf/HashMap.h>
+#include <wtf/MainThread.h>
+#include <wtf/Noncopyable.h>
+#include <wtf/StdLibExtras.h>
+#include <wtf/Threading.h>
+#include <wtf/ThreadSpecific.h>
+
+namespace WebCore {
+
+// DOM binding algorithm:
+//
+// There are two kinds of DOM objects:
+// 1. DOM tree nodes, such as Document, HTMLElement, ...
+//    there classes implements TreeShared<T> interface;
+// 2. Non-node DOM objects, such as CSSRule, Location, etc.
+//    these classes implement a ref-counted scheme.
+//
+// A DOM object may have a JS wrapper object. If a tree node
+// is alive, its JS wrapper must be kept alive even it is not
+// reachable from JS roots.
+// However, JS wrappers of non-node objects can go away if
+// not reachable from other JS objects. It works like a cache.
+//
+// DOM objects are ref-counted, and JS objects are traced from
+// a set of root objects. They can create a cycle. To break
+// cycles, we do following:
+//   Handles from DOM objects to JS wrappers are always weak,
+// so JS wrappers of non-node object cannot create a cycle.
+//   Before starting a global GC, we create a virtual connection
+// between nodes in the same tree in the JS heap. If the wrapper
+// of one node in a tree is alive, wrappers of all nodes in
+// the same tree are considered alive. This is done by creating
+// object groups in GC prologue callbacks. The mark-compact
+// collector will remove these groups after each GC.
+//
+// DOM objects should be deref-ed from the owning thread, not the GC thread
+// that does not own them. In V8, GC can kick in from any thread. To ensure
+// that DOM objects are always deref-ed from the owning thread when running
+// V8 in multi-threading environment, we do following:
+// 1. Maintain a thread specific DOM wrapper map for each object map.
+//    (We're using TLS support from WTF instead of base since V8Bindings
+//     does not depend on base. We further assume that all child threads
+//     running V8 instances are created by WTF and thus a destructor will
+//     be called to clean up all thread specific data.)
+// 2. When GC happens:
+//    2.1. If the dead object is in GC thread's map, remove the JS reference
+//         and deref the DOM object.
+//    2.2. Otherwise, go through all thread maps to find the owning thread.
+//         Remove the JS reference from the owning thread's map and move the
+//         DOM object to a delayed queue. Post a task to the owning thread
+//         to have it deref-ed from the owning thread at later time.
+// 3. When a thread is tearing down, invoke a cleanup routine to go through
+//    all objects in the delayed queue and the thread map and deref all of
+//    them.
+
+static void weakDOMObjectCallback(v8::Persistent<v8::Value> v8Object, void* domObject);
+static void weakNodeCallback(v8::Persistent<v8::Value> v8Object, void* domObject);
+
+#if ENABLE(SVG)
+static void weakSVGElementInstanceCallback(v8::Persistent<v8::Value> v8Object, void* domObject);
+
+// SVG non-node elements may have a reference to a context node which should be notified when the element is change.
+static void weakSVGObjectWithContextCallback(v8::Persistent<v8::Value> v8Object, void* domObject);
+#endif
+
+// This is to ensure that we will deref DOM objects from the owning thread, not the GC thread.
+// The helper function will be scheduled by the GC thread to get called from the owning thread.
+static void derefDelayedObjectsInCurrentThread(void*);
+
+// This should be called to remove all DOM objects associated with the current thread when it is tearing down.
+static void removeAllDOMObjectsInCurrentThread();
+
+// A map from a thread ID to thread's specific data.
+class ThreadSpecificDOMData;
+typedef WTF::HashMap<WTF::ThreadIdentifier, ThreadSpecificDOMData*> DOMThreadMap;
+static DOMThreadMap& domThreadMap()
+{
+    DEFINE_STATIC_LOCAL(DOMThreadMap, staticDOMThreadMap, ());
+    return staticDOMThreadMap;
+}
+
+// Mutex to protect against concurrent access of domThreadMap.
+static WTF::Mutex& domThreadMapMutex()
+{
+    DEFINE_STATIC_LOCAL(WTF::Mutex, staticDOMThreadMapMutex, ());
+    return staticDOMThreadMapMutex;
+}
+
+class ThreadSpecificDOMData : Noncopyable {
+public:
+    enum DOMWrapperMapType {
+        DOMNodeMap,
+        DOMObjectMap,
+        ActiveDOMObjectMap,
+#if ENABLE(SVG)
+        DOMSVGElementInstanceMap,
+        DOMSVGObjectWithContextMap
+#endif
+    };
+
+    typedef WTF::HashMap<void*, V8ClassIndex::V8WrapperType> DelayedObjectMap;
+
+    template <class KeyType>
+    class InternalDOMWrapperMap : public DOMWrapperMap<KeyType> {
+    public:
+        InternalDOMWrapperMap(v8::WeakReferenceCallback callback)
+            : DOMWrapperMap<KeyType>(callback) { }
+
+        virtual void forget(KeyType*);
+
+        void forgetOnly(KeyType* object)
+        {
+            DOMWrapperMap<KeyType>::forget(object);
+        }
+    };
+
+    ThreadSpecificDOMData()
+        : m_domNodeMap(0)
+        , m_domObjectMap(0)
+        , m_activeDomObjectMap(0)
+#if ENABLE(SVG)
+        , m_domSvgElementInstanceMap(0)
+        , m_domSvgObjectWithContextMap(0)
+#endif
+        , m_delayedProcessingScheduled(false)
+        , m_isMainThread(WTF::isMainThread())
+    {
+        WTF::MutexLocker locker(domThreadMapMutex());
+        domThreadMap().set(WTF::currentThread(), this);
+    }
+
+    virtual ~ThreadSpecificDOMData()
+    {
+        WTF::MutexLocker locker(domThreadMapMutex());
+        domThreadMap().remove(WTF::currentThread());
+    }
+
+    void* getDOMWrapperMap(DOMWrapperMapType type)
+    {
+        switch (type) {
+        case DOMNodeMap:
+            return m_domNodeMap;
+        case DOMObjectMap:
+            return m_domObjectMap;
+        case ActiveDOMObjectMap:
+            return m_activeDomObjectMap;
+#if ENABLE(SVG)
+        case DOMSVGElementInstanceMap:
+            return m_domSvgElementInstanceMap;
+        case DOMSVGObjectWithContextMap:
+            return m_domSvgObjectWithContextMap;
+#endif
+        }
+
+        ASSERT_NOT_REACHED();
+        return 0;
+    }
+
+    InternalDOMWrapperMap<Node>& domNodeMap() { return *m_domNodeMap; }
+    InternalDOMWrapperMap<void>& domObjectMap() { return *m_domObjectMap; }
+    InternalDOMWrapperMap<void>& activeDomObjectMap() { return *m_activeDomObjectMap; }
+#if ENABLE(SVG)
+    InternalDOMWrapperMap<SVGElementInstance>& domSvgElementInstanceMap() { return *m_domSvgElementInstanceMap; }
+    InternalDOMWrapperMap<void>& domSvgObjectWithContextMap() { return *m_domSvgObjectWithContextMap; }
+#endif
+
+    DelayedObjectMap& delayedObjectMap() { return m_delayedObjectMap; }
+    bool delayedProcessingScheduled() const { return m_delayedProcessingScheduled; }
+    void setDelayedProcessingScheduled(bool value) { m_delayedProcessingScheduled = value; }
+    bool isMainThread() const { return m_isMainThread; }
+
+protected:
+    InternalDOMWrapperMap<Node>* m_domNodeMap;
+    InternalDOMWrapperMap<void>* m_domObjectMap;
+    InternalDOMWrapperMap<void>* m_activeDomObjectMap;
+#if ENABLE(SVG)
+    InternalDOMWrapperMap<SVGElementInstance>* m_domSvgElementInstanceMap;
+    InternalDOMWrapperMap<void>* m_domSvgObjectWithContextMap;
+#endif
+
+    // Stores all the DOM objects that are delayed to be processed when the owning thread gains control.
+    DelayedObjectMap m_delayedObjectMap;
+
+    // The flag to indicate if the task to do the delayed process has already been posted.
+    bool m_delayedProcessingScheduled;
+
+    bool m_isMainThread;
+};
+
+// This encapsulates thread-specific DOM data for non-main thread. All the maps in it are created dynamically.
+class NonMainThreadSpecificDOMData : public ThreadSpecificDOMData {
+public:
+    NonMainThreadSpecificDOMData()
+    {
+        m_domNodeMap = new InternalDOMWrapperMap<Node>(&weakNodeCallback);
+        m_domObjectMap = new InternalDOMWrapperMap<void>(weakDOMObjectCallback);
+        m_activeDomObjectMap = new InternalDOMWrapperMap<void>(weakActiveDOMObjectCallback);
+#if ENABLE(SVG)
+        m_domSvgElementInstanceMap = new InternalDOMWrapperMap<SVGElementInstance>(weakSVGElementInstanceCallback);
+        m_domSvgObjectWithContextMap = new InternalDOMWrapperMap<void>(weakSVGObjectWithContextCallback);
+#endif
+    }
+
+    // This is called when WTF thread is tearing down.
+    // We assume that all child threads running V8 instances are created by WTF.
+    virtual ~NonMainThreadSpecificDOMData()
+    {
+        removeAllDOMObjectsInCurrentThread();
+
+        delete m_domNodeMap;
+        delete m_domObjectMap;
+        delete m_activeDomObjectMap;
+#if ENABLE(SVG)
+        delete m_domSvgElementInstanceMap;
+        delete m_domSvgObjectWithContextMap;
+#endif
+    }
+};
+
+// This encapsulates thread-specific DOM data for the main thread. All the maps in it are static.
+// This is because we are unable to rely on WTF::ThreadSpecificThreadExit to do the cleanup since the place that tears down the main thread can not call any WTF functions.
+class MainThreadSpecificDOMData : public ThreadSpecificDOMData {
+public:
+    MainThreadSpecificDOMData()
+        : m_staticDomNodeMap(weakNodeCallback)
+        , m_staticDomObjectMap(weakDOMObjectCallback)
+        , m_staticActiveDomObjectMap(weakActiveDOMObjectCallback)
+#if ENABLE(SVG)
+        , m_staticDomSvgElementInstanceMap(weakSVGElementInstanceCallback)
+        , m_staticDomSvgObjectWithContextMap(weakSVGObjectWithContextCallback)
+#endif
+    {
+        m_domNodeMap = &m_staticDomNodeMap;
+        m_domObjectMap = &m_staticDomObjectMap;
+        m_activeDomObjectMap = &m_staticActiveDomObjectMap;
+#if ENABLE(SVG)
+        m_domSvgElementInstanceMap = &m_staticDomSvgElementInstanceMap;
+        m_domSvgObjectWithContextMap = &m_staticDomSvgObjectWithContextMap;
+#endif
+    }
+
+private:
+    InternalDOMWrapperMap<Node> m_staticDomNodeMap;
+    InternalDOMWrapperMap<void> m_staticDomObjectMap;
+    InternalDOMWrapperMap<void> m_staticActiveDomObjectMap;
+#if ENABLE(SVG)    
+    InternalDOMWrapperMap<SVGElementInstance> m_staticDomSvgElementInstanceMap;
+    InternalDOMWrapperMap<void> m_staticDomSvgObjectWithContextMap;
+#endif
+};
+
+DEFINE_STATIC_LOCAL(WTF::ThreadSpecific<NonMainThreadSpecificDOMData>, threadSpecificDOMData, ());
+
+template<typename T>
+static void handleWeakObjectInOwningThread(ThreadSpecificDOMData::DOMWrapperMapType mapType, V8ClassIndex::V8WrapperType objectType, T*);
+
+ThreadSpecificDOMData& getThreadSpecificDOMData()
+{
+    if (WTF::isMainThread()) {
+        DEFINE_STATIC_LOCAL(MainThreadSpecificDOMData, mainThreadSpecificDOMData, ());
+        return mainThreadSpecificDOMData;
+    }
+    return *threadSpecificDOMData;
+}
+
+template <class KeyType>
+void ThreadSpecificDOMData::InternalDOMWrapperMap<KeyType>::forget(KeyType* object)
+{
+    DOMWrapperMap<KeyType>::forget(object);
+
+    ThreadSpecificDOMData::DelayedObjectMap& delayedObjectMap = getThreadSpecificDOMData().delayedObjectMap();
+    delayedObjectMap.take(object);
+}
+
+DOMWrapperMap<Node>& getDOMNodeMap()
+{
+    return getThreadSpecificDOMData().domNodeMap();
+}
+
+DOMWrapperMap<void>& getDOMObjectMap()
+{
+    return getThreadSpecificDOMData().domObjectMap();
+}
+
+DOMWrapperMap<void>& getActiveDOMObjectMap()
+{
+    return getThreadSpecificDOMData().activeDomObjectMap();
+}
+
+#if ENABLE(SVG)
+DOMWrapperMap<SVGElementInstance>& getDOMSVGElementInstanceMap()
+{
+    return getThreadSpecificDOMData().domSvgElementInstanceMap();
+}
+
+static void weakSVGElementInstanceCallback(v8::Persistent<v8::Value> v8Object, void* domObject)
+{
+    SVGElementInstance* instance = static_cast<SVGElementInstance*>(domObject);
+
+    ThreadSpecificDOMData::InternalDOMWrapperMap<SVGElementInstance>& map = static_cast<ThreadSpecificDOMData::InternalDOMWrapperMap<SVGElementInstance>&>(getDOMSVGElementInstanceMap());
+    if (map.contains(instance)) {
+        instance->deref();
+        map.forgetOnly(instance);
+    } else
+        handleWeakObjectInOwningThread(ThreadSpecificDOMData::DOMSVGElementInstanceMap, V8ClassIndex::SVGELEMENTINSTANCE, instance);
+}
+
+// Map of SVG objects with contexts to V8 objects
+DOMWrapperMap<void>& getDOMSVGObjectWithContextMap()
+{
+    return getThreadSpecificDOMData().domSvgObjectWithContextMap();
+}
+
+static void weakSVGObjectWithContextCallback(v8::Persistent<v8::Value> v8Object, void* domObject)
+{
+    v8::HandleScope scope;
+    ASSERT(v8Object->IsObject());
+
+    V8ClassIndex::V8WrapperType type = V8Proxy::GetDOMWrapperType(v8::Handle<v8::Object>::Cast(v8Object));
+
+    ThreadSpecificDOMData::InternalDOMWrapperMap<void>& map = static_cast<ThreadSpecificDOMData::InternalDOMWrapperMap<void>&>(getDOMSVGObjectWithContextMap());
+    if (map.contains(domObject)) {
+        // The forget function removes object from the map and disposes the wrapper.
+        map.forgetOnly(domObject);
+
+        switch (type) {
+#define MakeCase(type, name)     \
+            case V8ClassIndex::type: static_cast<name*>(domObject)->deref(); break;
+        SVG_OBJECT_TYPES(MakeCase)
+#undef MakeCase
+#define MakeCase(type, name)     \
+            case V8ClassIndex::type:    \
+                static_cast<V8SVGPODTypeWrapper<name>*>(domObject)->deref(); break;
+        SVG_POD_NATIVE_TYPES(MakeCase)
+#undef MakeCase
+        default:
+            ASSERT_NOT_REACHED();
+            break;
+        }
+    } else
+        handleWeakObjectInOwningThread(ThreadSpecificDOMData::DOMSVGObjectWithContextMap, type, domObject);
+}
+#endif // ENABLE(SVG)
+
+// Called when the dead object is not in GC thread's map. Go through all thread maps to find the one containing it.
+// Then clear the JS reference and push the DOM object into the delayed queue for it to be deref-ed at later time from the owning thread.
+// * This is called when the GC thread is not the owning thread.
+// * This can be called on any thread that has GC running.
+// * Only one V8 instance is running at a time due to V8::Locker. So we don't need to worry about concurrency.
+template<typename T>
+static void handleWeakObjectInOwningThread(ThreadSpecificDOMData::DOMWrapperMapType mapType, V8ClassIndex::V8WrapperType objectType, T* object)
+{
+    WTF::MutexLocker locker(domThreadMapMutex());
+    for (typename DOMThreadMap::iterator iter(domThreadMap().begin()); iter != domThreadMap().end(); ++iter) {
+        WTF::ThreadIdentifier threadID = iter->first;
+        ThreadSpecificDOMData* threadData = iter->second;
+
+        // Skip the current thread that is GC thread.
+        if (threadID == WTF::currentThread()) {
+            ASSERT(!static_cast<DOMWrapperMap<T>*>(threadData->getDOMWrapperMap(mapType))->contains(object));
+            continue;
+        }
+
+        ThreadSpecificDOMData::InternalDOMWrapperMap<T>* domMap = static_cast<ThreadSpecificDOMData::InternalDOMWrapperMap<T>*>(threadData->getDOMWrapperMap(mapType));
+        if (domMap->contains(object)) {
+            // Clear the JS reference.
+            domMap->forgetOnly(object);
+
+            // Push into the delayed queue.
+            threadData->delayedObjectMap().set(object, objectType);
+
+            // Post a task to the owning thread in order to process the delayed queue.
+            // FIXME: For now, we can only post to main thread due to WTF task posting limitation. We will fix this when we work on nested worker.
+            if (!threadData->delayedProcessingScheduled()) {
+                threadData->setDelayedProcessingScheduled(true);
+                if (threadData->isMainThread())
+                    WTF::callOnMainThread(&derefDelayedObjectsInCurrentThread, 0);
+            }
+
+            break;
+        }
+    }
+}
+
+// Called when the object is near death (not reachable from JS roots).
+// It is time to remove the entry from the table and dispose the handle.
+static void weakDOMObjectCallback(v8::Persistent<v8::Value> v8Object, void* domObject)
+{
+    v8::HandleScope scope;
+    ASSERT(v8Object->IsObject());
+
+    V8ClassIndex::V8WrapperType type = V8Proxy::GetDOMWrapperType(v8::Handle<v8::Object>::Cast(v8Object));
+
+    ThreadSpecificDOMData::InternalDOMWrapperMap<void>& map = static_cast<ThreadSpecificDOMData::InternalDOMWrapperMap<void>&>(getDOMObjectMap());
+    if (map.contains(domObject)) {
+        // The forget function removes object from the map and disposes the wrapper.
+        map.forgetOnly(domObject);
+
+        switch (type) {
+#define MakeCase(type, name)   \
+            case V8ClassIndex::type: static_cast<name*>(domObject)->deref(); break;
+        DOM_OBJECT_TYPES(MakeCase)
+#undef MakeCase
+        default:
+            ASSERT_NOT_REACHED();
+            break;
+        }
+    } else
+        handleWeakObjectInOwningThread(ThreadSpecificDOMData::DOMObjectMap, type, domObject);
+}
+
+void weakActiveDOMObjectCallback(v8::Persistent<v8::Value> v8Object, void* domObject)
+{
+    v8::HandleScope scope;
+    ASSERT(v8Object->IsObject());
+
+    V8ClassIndex::V8WrapperType type = V8Proxy::GetDOMWrapperType(v8::Handle<v8::Object>::Cast(v8Object));
+
+    ThreadSpecificDOMData::InternalDOMWrapperMap<void>& map = static_cast<ThreadSpecificDOMData::InternalDOMWrapperMap<void>&>(getActiveDOMObjectMap());
+    if (map.contains(domObject)) {
+        // The forget function removes object from the map and disposes the wrapper.
+        map.forgetOnly(domObject);
+
+        switch (type) {
+#define MakeCase(type, name)   \
+            case V8ClassIndex::type: static_cast<name*>(domObject)->deref(); break;
+        ACTIVE_DOM_OBJECT_TYPES(MakeCase)
+#undef MakeCase
+        default:
+            ASSERT_NOT_REACHED();
+            break;
+        }
+    } else
+        handleWeakObjectInOwningThread(ThreadSpecificDOMData::ActiveDOMObjectMap, type, domObject);
+}
+
+static void weakNodeCallback(v8::Persistent<v8::Value> v8Object, void* domObject)
+{
+    Node* node = static_cast<Node*>(domObject);
+
+    ThreadSpecificDOMData::InternalDOMWrapperMap<Node>& map = static_cast<ThreadSpecificDOMData::InternalDOMWrapperMap<Node>&>(getDOMNodeMap());
+    if (map.contains(node)) {
+        map.forgetOnly(node);
+        node->deref();
+    } else
+        handleWeakObjectInOwningThread<Node>(ThreadSpecificDOMData::DOMNodeMap, V8ClassIndex::NODE, node);
+}
+
+static void derefObject(V8ClassIndex::V8WrapperType type, void* domObject)
+{
+    switch (type) {
+    case V8ClassIndex::NODE:
+        static_cast<Node*>(domObject)->deref();
+        break;
+
+#define MakeCase(type, name)   \
+        case V8ClassIndex::type: static_cast<name*>(domObject)->deref(); break;
+    DOM_OBJECT_TYPES(MakeCase)   // This includes both active and non-active.
+#undef MakeCase
+
+#if ENABLE(SVG)
+#define MakeCase(type, name)     \
+        case V8ClassIndex::type: static_cast<name*>(domObject)->deref(); break;
+    SVG_OBJECT_TYPES(MakeCase)   // This also includes SVGElementInstance.
+#undef MakeCase
+
+#define MakeCase(type, name)     \
+        case V8ClassIndex::type:    \
+            static_cast<V8SVGPODTypeWrapper<name>*>(domObject)->deref(); break;
+    SVG_POD_NATIVE_TYPES(MakeCase)
+#undef MakeCase
+#endif
+
+    default:
+        ASSERT_NOT_REACHED();
+        break;
+    }
+}
+
+static void derefDelayedObjects()
+{
+    WTF::MutexLocker locker(domThreadMapMutex());
+
+    getThreadSpecificDOMData().setDelayedProcessingScheduled(false);
+
+    ThreadSpecificDOMData::DelayedObjectMap& delayedObjectMap = getThreadSpecificDOMData().delayedObjectMap();
+    for (ThreadSpecificDOMData::DelayedObjectMap::iterator iter(delayedObjectMap.begin()); iter != delayedObjectMap.end(); ++iter) {
+        derefObject(iter->second, iter->first);
+    }
+    delayedObjectMap.clear();
+}
+
+static void derefDelayedObjectsInCurrentThread(void*)
+{
+    derefDelayedObjects();
+}
+
+template<typename T>
+static void removeObjectsFromWrapperMap(DOMWrapperMap<T>& domMap)
+{
+    for (typename WTF::HashMap<T*, v8::Object*>::iterator iter(domMap.impl().begin()); iter != domMap.impl().end(); ++iter) {
+        T* domObject = static_cast<T*>(iter->first);
+        v8::Persistent<v8::Object> v8Object(iter->second);
+
+        V8ClassIndex::V8WrapperType type = V8Proxy::GetDOMWrapperType(v8::Handle<v8::Object>::Cast(v8Object));
+
+        // Deref the DOM object.
+        derefObject(type, domObject);
+
+        // Clear the JS wrapper.
+        v8Object.Dispose();
+    }
+    domMap.impl().clear();
+}
+
+static void removeAllDOMObjectsInCurrentThreadHelper()
+{
+    v8::HandleScope scope;
+
+    // Deref all objects in the delayed queue.
+    derefDelayedObjects();
+
+    // Remove all DOM nodes.
+    removeObjectsFromWrapperMap<Node>(getDOMNodeMap());
+
+    // Remove all DOM objects in the wrapper map.
+    removeObjectsFromWrapperMap<void>(getDOMObjectMap());
+
+    // Remove all active DOM objects in the wrapper map.
+    removeObjectsFromWrapperMap<void>(getActiveDOMObjectMap());
+
+#if ENABLE(SVG)
+    // Remove all SVG element instances in the wrapper map.
+    removeObjectsFromWrapperMap<SVGElementInstance>(getDOMSVGElementInstanceMap());
+
+    // Remove all SVG objects with context in the wrapper map.
+    removeObjectsFromWrapperMap<void>(getDOMSVGObjectWithContextMap());
+#endif
+}
+
+static void removeAllDOMObjectsInCurrentThread()
+{
+    // Use the locker only if it has already been invoked before, as by worker thread.
+    if (v8::Locker::IsActive()) {
+        v8::Locker locker;
+        removeAllDOMObjectsInCurrentThreadHelper();
+    } else
+        removeAllDOMObjectsInCurrentThreadHelper();
+}
+
+} // namespace WebCore