Fix tracking of computed fields when field type tracking is disabled.

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/247523004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20901 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/objects.cc

@@ -63,8 +63,8 @@ namespace internal {
 
 Handle<HeapType> Object::OptimalType(Isolate* isolate,
                                      Representation representation) {
+  if (representation.IsNone()) return HeapType::None(isolate);
   if (FLAG_track_field_types) {
-    if (representation.IsNone()) return HeapType::None(isolate);
     if (representation.IsHeapObject() && IsHeapObject()) {
       // We can track only JavaScript objects with stable maps.
       Handle<Map> map(HeapObject::cast(this)->map(), isolate);