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

Source/bindings/tests/results/core/V8TestNode.cpp

Index: Source/bindings/tests/results/core/V8TestNode.cpp
diff --git a/Source/bindings/tests/results/core/V8TestNode.cpp b/Source/bindings/tests/results/core/V8TestNode.cpp
index 329118b79f4faaf90debbcc8b9f509273f5137eb..f85862e6c82c08da0acfc1b8d06da302de2edcb4 100644
--- a/Source/bindings/tests/results/core/V8TestNode.cpp
+++ b/Source/bindings/tests/results/core/V8TestNode.cpp
@@ -211,6 +211,10 @@ static void installV8TestNodeTemplate(v8::Local<v8::FunctionTemplate> functionTe
     v8::Local<v8::ObjectTemplate> prototypeTemplate = functionTemplate->PrototypeTemplate();
     ALLOW_UNUSED_LOCAL(prototypeTemplate);
 
+    instanceTemplate->Set(v8::Symbol::GetToStringTag(isolate), v8AtomicString(isolate, "TestNode"));
+
+    prototypeTemplate->Set(v8::Symbol::GetToStringTag(isolate), v8AtomicString(isolate, "TestNodePrototype"));
+
     // Custom toString template
     functionTemplate->Set(v8AtomicString(isolate, "toString"), V8PerIsolateData::from(isolate)->toStringTemplate());
 }