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

Source/bindings/tests/results/core/V8TestInterfaceConstructor3.cpp

Index: Source/bindings/tests/results/core/V8TestInterfaceConstructor3.cpp
diff --git a/Source/bindings/tests/results/core/V8TestInterfaceConstructor3.cpp b/Source/bindings/tests/results/core/V8TestInterfaceConstructor3.cpp
index 0bbdb2f93be39049cc9412c260d665658046db7e..95bda2904141c3f9f162c9cf5602bdff8d00fcb0 100644
--- a/Source/bindings/tests/results/core/V8TestInterfaceConstructor3.cpp
+++ b/Source/bindings/tests/results/core/V8TestInterfaceConstructor3.cpp
@@ -82,6 +82,10 @@ static void installV8TestInterfaceConstructor3Template(v8::Local<v8::FunctionTem
     v8::Local<v8::ObjectTemplate> prototypeTemplate = functionTemplate->PrototypeTemplate();
     ALLOW_UNUSED_LOCAL(prototypeTemplate);
 
+    instanceTemplate->Set(v8::Symbol::GetToStringTag(isolate), v8AtomicString(isolate, "TestInterfaceConstructor3"));
+
+    prototypeTemplate->Set(v8::Symbol::GetToStringTag(isolate), v8AtomicString(isolate, "TestInterfaceConstructor3Prototype"));
+
     // Custom toString template
     functionTemplate->Set(v8AtomicString(isolate, "toString"), V8PerIsolateData::from(isolate)->toStringTemplate());
 }