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

Source/bindings/tests/results/core/V8TestInterface2.cpp

Index: Source/bindings/tests/results/core/V8TestInterface2.cpp
diff --git a/Source/bindings/tests/results/core/V8TestInterface2.cpp b/Source/bindings/tests/results/core/V8TestInterface2.cpp
index 53b1b466f4735e82799adb1d6846b627243f26ac..b95ccd31a4d74891a2719fc038b62a17c93cedef 100644
--- a/Source/bindings/tests/results/core/V8TestInterface2.cpp
+++ b/Source/bindings/tests/results/core/V8TestInterface2.cpp
@@ -679,6 +679,10 @@ static void installV8TestInterface2Template(v8::Local<v8::FunctionTemplate> func
     static const V8DOMConfiguration::SymbolKeyedMethodConfiguration symbolKeyedIteratorConfiguration = { v8::Symbol::GetIterator, TestInterface2V8Internal::iteratorMethodCallback, 0, V8DOMConfiguration::ExposedToAllScripts };
     V8DOMConfiguration::installMethod(isolate, prototypeTemplate, defaultSignature, v8::DontDelete, symbolKeyedIteratorConfiguration);
 
+    instanceTemplate->Set(v8::Symbol::GetToStringTag(isolate), v8AtomicString(isolate, "TestInterface2"));
+
+    prototypeTemplate->Set(v8::Symbol::GetToStringTag(isolate), v8AtomicString(isolate, "TestInterface2Prototype"));
+
     // Custom toString template
     functionTemplate->Set(v8AtomicString(isolate, "toString"), V8PerIsolateData::from(isolate)->toStringTemplate());
 }