Allow SetHiddenValue to accept empty value.

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 b646049f335e0edd32bb56fd6a025edfd0139895..77c0952520b6bb5dcad3bc9f764d42a7a0f2a35a 100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -2081,6 +2081,10 @@ THREADED_TEST(HiddenProperties) {
 
   HEAP->CollectAllGarbage(i::Heap::kNoGCFlags);
 
+  CHECK(obj->SetHiddenValue(key, Handle<Value>()));
+  CHECK(obj->GetHiddenValue(key).IsEmpty());
+
+  CHECK(obj->SetHiddenValue(key, v8::Integer::New(2002)));
   CHECK(obj->DeleteHiddenValue(key));
   CHECK(obj->GetHiddenValue(key).IsEmpty());
 }