Provide an Expando implementation for the VM.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index af8695abcf43b802c1adeeeed8abc8553a5c65a3..c6674c0637633b451a3f4dfce9074c8711835b65 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -444,6 +444,8 @@ RawClass* Object::CreateAndRegisterInterface(const char* cname,
 void Object::RegisterClass(const Class& cls,
                            const String& name,
                            const Library& lib) {
+  ASSERT(name.Length() > 0);
+  ASSERT(name.CharAt(0) != '_');
   cls.set_name(name);
   lib.AddClass(cls);
 }
@@ -452,6 +454,8 @@ void Object::RegisterClass(const Class& cls,
 void Object::RegisterPrivateClass(const Class& cls,
                                   const String& public_class_name,
                                   const Library& lib) {
+  ASSERT(public_class_name.Length() > 0);
+  ASSERT(public_class_name.CharAt(0) == '_');
   String& str = String::Handle();
   str = lib.PrivateName(public_class_name);
   cls.set_name(str);
@@ -624,12 +628,6 @@ RawError* Object::Init(Isolate* isolate) {
   RegisterClass(cls, name, core_impl_lib);
   pending_classes.Add(cls, Heap::kOld);
 
-  cls = Class::New<WeakProperty>();
-  object_store->set_weak_property_class(cls);
-  name = Symbols::WeakProperty();
-  RegisterClass(cls, name, core_impl_lib);
-  pending_classes.Add(cls, Heap::kOld);
-
   // Initialize the base interfaces used by the core VM classes.
   const Script& script = Script::Handle(Bootstrap::LoadCoreScript(false));
 
@@ -747,6 +745,11 @@ RawError* Object::Init(Isolate* isolate) {
   name = Symbols::_ExternalFloat64Array();
   RegisterPrivateClass(cls, name, core_lib);
 
+  cls = Class::New<WeakProperty>();
+  object_store->set_weak_property_class(cls);
+  name = Symbols::_WeakProperty();
+  RegisterPrivateClass(cls, name, core_lib);
+
   // Set the super type of class Stacktrace to Object type so that the
   // 'toString' method is implemented.
   cls = object_store->stacktrace_class();
@@ -11144,7 +11147,7 @@ RawWeakProperty* WeakProperty::New(Heap::Space space) {
 
 
 const char* WeakProperty::ToCString() const {
-  return "WeakProperty";
+  return "_WeakProperty";
 }
 
 }  // namespace dart