Re-ship @@toStringTag

test/cctest/test-api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 22020 matching lines @@
 
   allowed_access = true;
   env->Global()->Set(v8_str("object"), object);
   object->Set(v8::Symbol::GetToStringTag(isolate), v8_str("hello"));
 
   // Access check is allowed, and the toStringTag is read
   CompileRun("var result = Object.prototype.toString.call(object)");
   ExpectString("result", "[object hello]");
   ExpectString("object[Symbol.toStringTag]", "hello");
 
+  // ToString through the API should succeed too.
+  String::Utf8Value result_allowed(
+      object->ObjectProtoToString(env.local()).ToLocalChecked());
+  CHECK_EQ(0, strcmp(*result_allowed, "[object hello]"));
+
   // If access check fails, the value of @@toStringTag is ignored
   allowed_access = false;
   CompileRun("var result = Object.prototype.toString.call(object)");
   ExpectString("result", "[object Object]");
   ExpectTrue("object[Symbol.toStringTag] === undefined");
+
+  // ToString through the API should also fail.
+  String::Utf8Value result_denied(
+      object->ObjectProtoToString(env.local()).ToLocalChecked());
+  CHECK_EQ(0, strcmp(*result_denied, "[object Object]"));
 }
 
 
 TEST(ObjectTemplateIntrinsics) {
   v8::Isolate* isolate = CcTest::isolate();
   v8::HandleScope scope(isolate);
   LocalContext env;
 
   Local<ObjectTemplate> object_template = v8::ObjectTemplate::New(isolate);
   object_template->SetIntrinsicDataProperty(v8_str("values"),
@@ skipping 14 matching lines @@
     env2->Global()->Set(v8_str("obj2"), object2);
     ExpectString("typeof obj2.values", "function");
     CHECK_NE(*object->Get(v8_str("values")), *object2->Get(v8_str("values")));
 
     auto values2 = Local<Function>::Cast(object2->Get(v8_str("values")));
     auto fn2 = i::Handle<i::JSFunction>::cast(v8::Utils::OpenHandle(*values2));
     auto ctx2 = v8::Utils::OpenHandle(*env2.local());
     CHECK_EQ(fn2->GetCreationContext(), *ctx2);
   }
 }