Update ObjectToString to Harmony-draft algorithm

test/cctest/test-api.cc

Index: test/cctest/test-api.cc
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
index 283bcb8e0d66d869a7faf3751d761b5a3fb5a3c3..dceb2a507f76ba3a6afe55838a00cd91acf12108 100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -13489,6 +13489,20 @@ THREADED_TEST(ObjectProtoToString) {
   Local<Value> object = v8_compile("new Object()")->Run();
   value = object.As<v8::Object>()->ObjectProtoToString();
   CHECK(value->IsString() && value->Equals(v8_str("[object Object]")));
+
+  // Check that ES6 semantics using @@toStringTag work
+  i::FLAG_harmony_tostring = true;
+  Local<v8::Symbol> toStringTag = v8::Symbol::GetToStringTag(isolate);
+
+  object = v8_compile("new Object()")->Run();
+  object.As<v8::Object>()->Set(toStringTag, v8_str("Foo"));
+  value = object.As<v8::Object>()->ObjectProtoToString();
+  CHECK(value->IsString() && value->Equals(v8_str("[object Foo]")));
+
+  object = v8_compile("new Object()")->Run();
+  object.As<v8::Object>()->Set(toStringTag, v8_str("Array"));
+  value = object.As<v8::Object>()->ObjectProtoToString();
+  CHECK(value->IsString() && value->Equals(v8_str("[object ~Array]")));

[Dmitry Lomov (no reviews), 2014/10/18 15:16:48]

Add a test that creates an object with a getter for toStringTag. Actually two:
one that completes normally and one that throws. 

Add tests for all cases from 19.1.3.6.

 }