[DO NOT LAND] Set @@toStringTag for DOM object prototypes

Source/bindings/tests/results/core/V8TestInterfaceEmpty.cpp

Index: Source/bindings/tests/results/core/V8TestInterfaceEmpty.cpp
diff --git a/Source/bindings/tests/results/core/V8TestInterfaceEmpty.cpp b/Source/bindings/tests/results/core/V8TestInterfaceEmpty.cpp
index 6ea63bb60a926013a42b4bfd357d330d4b66717b..931f32c13918c116172c50e5d31670d5e4239379 100644
--- a/Source/bindings/tests/results/core/V8TestInterfaceEmpty.cpp
+++ b/Source/bindings/tests/results/core/V8TestInterfaceEmpty.cpp
@@ -44,6 +44,8 @@ static void installV8TestInterfaceEmptyTemplate(v8::Local<v8::FunctionTemplate>
     v8::Local<v8::ObjectTemplate> prototypeTemplate = functionTemplate->PrototypeTemplate();
     ALLOW_UNUSED_LOCAL(prototypeTemplate);
 
+    prototypeTemplate->Set(v8::Symbol::GetToStringTag(isolate), v8AtomicString(isolate, "TestInterfaceEmpty"));
+
     // Custom toString template
     functionTemplate->Set(v8AtomicString(isolate, "toString"), V8PerIsolateData::from(isolate)->toStringTemplate());
 }