Drop [TypeChecking=Nullable]; deduce from attribute type instead

Source/bindings/tests/results/V8TestInterfaceEventConstructor.cpp

Index: Source/bindings/tests/results/V8TestInterfaceEventConstructor.cpp
diff --git a/Source/bindings/tests/results/V8TestInterfaceEventConstructor.cpp b/Source/bindings/tests/results/V8TestInterfaceEventConstructor.cpp
index 8fcd01266b440865c8bfd8b34e5163d648300f9c..c00620fd7b6dc06928639bbd7aa6448736a98858 100644
--- a/Source/bindings/tests/results/V8TestInterfaceEventConstructor.cpp
+++ b/Source/bindings/tests/results/V8TestInterfaceEventConstructor.cpp
@@ -179,9 +179,8 @@ static void initializedByEventConstructorReadonlyNullableTestInterfaceEmptyAttri
 {
     v8::Handle<v8::Object> holder = info.Holder();
     TestInterfaceEventConstructor* impl = V8TestInterfaceEventConstructor::toNative(holder);
-    bool isNull = false;
-    RefPtr<TestInterfaceEmpty> cppValue(impl->initializedByEventConstructorReadonlyNullableTestInterfaceEmptyAttribute(isNull));
-    if (isNull) {
+    RefPtr<TestInterfaceEmpty> cppValue(impl->initializedByEventConstructorReadonlyNullableTestInterfaceEmptyAttribute());
+    if (!cppValue) {
         v8SetReturnValueNull(info);
         return;
     }