Remove leak of objects between isolated worlds on custom events.

Source/bindings/v8/custom/V8CustomEventCustom.cpp

Index: Source/bindings/v8/custom/V8CustomEventCustom.cpp
diff --git a/Source/bindings/v8/custom/V8CustomEventCustom.cpp b/Source/bindings/v8/custom/V8CustomEventCustom.cpp
index ff0f9b355c75a404d34f7125047a40ec5070b14d..53cda603055f29922d3fa50bf5c7f8893bf18b0a 100644
--- a/Source/bindings/v8/custom/V8CustomEventCustom.cpp
+++ b/Source/bindings/v8/custom/V8CustomEventCustom.cpp
@@ -48,6 +48,7 @@ namespace WebCore {
 void V8CustomEvent::detailAttrGetterCustom(v8::Local<v8::String> name, const v8::PropertyCallbackInfo<v8::Value>& info)
 {
     CustomEvent* imp = V8CustomEvent::toNative(info.Holder());
+    ASSERT(!imp->serializedScriptValue().get());
     RefPtr<SerializedScriptValue> serialized = imp->serializedScriptValue();
     if (serialized) {
         v8::Handle<v8::Value> value = info.Holder()->GetHiddenValue(V8HiddenPropertyName::detail());
@@ -58,7 +59,19 @@ void V8CustomEvent::detailAttrGetterCustom(v8::Local<v8::String> name, const v8:
         v8SetReturnValue(info, value);
         return;
     }
-    v8SetReturnValue(info, imp->detail().v8Value());
+    v8SetReturnValue(info, info.Holder()->GetHiddenValue(V8HiddenPropertyName::detail()));
+}
+
+void V8CustomEvent::initCustomEventMethodCustom(const v8::FunctionCallbackInfo<v8::Value>& args)
+{
+    CustomEvent* event = V8CustomEvent::toNative(args.Holder());
+    String typeArg = toWebCoreString(args[0]);
+    bool canBubbleArg = args[1]->BooleanValue();
+    bool cancelableArg = args[2]->BooleanValue();
+    v8::Handle<v8::Value> detailsArg = args[3];
+
+    args.Holder()->SetHiddenValue(V8HiddenPropertyName::detail(), detailsArg);
+    event->initEvent(typeArg, canBubbleArg, cancelableArg);
 }
 
 } // namespace WebCore