Reland: Reland: Implement new Blink IDL attribute [SetReference]

Source/bindings/v8/DOMDataStore.h

Index: Source/bindings/v8/DOMDataStore.h
diff --git a/Source/bindings/v8/DOMDataStore.h b/Source/bindings/v8/DOMDataStore.h
index 78bc836647fc2e29ed58c6cbb76b20fbbd4ffdbb..2fc5d4f8851227d04a4d3718d8e93e25ec3e297b 100644
--- a/Source/bindings/v8/DOMDataStore.h
+++ b/Source/bindings/v8/DOMDataStore.h
@@ -101,6 +101,20 @@ public:
     }
 
     template<typename V8T, typename T>
+    static UnsafePersistent<v8::Object> getWrapperPersistent(T* object, v8::Isolate* isolate)
+    {
+        if (ScriptWrappable::wrapperCanBeStoredInObject(object) && !canExistInWorker(object)) {
+            if (LIKELY(!DOMWrapperWorld::isolatedWorldsExist())) {
+                UnsafePersistent<v8::Object> unsafePersistent = ScriptWrappable::getUnsafeWrapperFromObject(object);
+                // Security: always guard against malicious tampering.
+                RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(unsafePersistent.isEmpty() || unsafePersistent.value()->GetAlignedPointerFromInternalField(v8DOMWrapperObjectIndex) == V8T::toInternalPointer(object));
+                return unsafePersistent;
+            }
+        }
+        return current(isolate)->template getPersistent<V8T>(object, isolate);
+    }
+
+    template<typename V8T, typename T>
     static void setWrapper(T* object, v8::Handle<v8::Object> wrapper, v8::Isolate* isolate, const WrapperConfiguration& configuration)
     {
         if (ScriptWrappable::wrapperCanBeStoredInObject(object) && !canExistInWorker(object)) {
@@ -127,6 +141,14 @@ public:
     }
 
     template<typename V8T, typename T>
+    inline UnsafePersistent<v8::Object> getPersistent(T* object, v8::Isolate* isolate)
+    {
+        if (ScriptWrappable::wrapperCanBeStoredInObject(object) && m_type == MainWorld)
+            return ScriptWrappable::getUnsafeWrapperFromObject(object);
+        return m_wrapperMap.get(V8T::toInternalPointer(object));
+    }
+
+    template<typename V8T, typename T>
     inline bool setReturnValueFrom(v8::ReturnValue<v8::Value> returnValue, T* object)
     {
         if (ScriptWrappable::wrapperCanBeStoredInObject(object) && m_type == MainWorld)