Expose the WeakProperty type.

runtime/lib/weak_property.cc

Index: runtime/lib/weak_property.cc
diff --git a/runtime/lib/weak_property.cc b/runtime/lib/weak_property.cc
new file mode 100644
index 0000000000000000000000000000000000000000..273cef8656fe4d15fea8d6aa68c036038fcf0a9c
--- /dev/null
+++ b/runtime/lib/weak_property.cc
@@ -0,0 +1,36 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "vm/bootstrap_natives.h"
+
+#include "vm/exceptions.h"
+#include "vm/native_entry.h"
+#include "vm/object.h"
+
+namespace dart {
+
+DEFINE_NATIVE_ENTRY(WeakProperty_new, 2) {
+  GET_NATIVE_ARGUMENT(Instance, key, arguments->At(0));
+  GET_NATIVE_ARGUMENT(Instance, value, arguments->At(1));
+  const WeakProperty& weak_property = WeakProperty::Handle(WeakProperty::New());
+  weak_property.set_key(key);
+  weak_property.set_value(value);
+  arguments->SetReturn(weak_property);
+}
+
+
+DEFINE_NATIVE_ENTRY(WeakProperty_getKey, 1) {
+  GET_NATIVE_ARGUMENT(WeakProperty, weak_property, arguments->At(0));
+  const Object& key = Object::Handle(weak_property.key());
+  arguments->SetReturn(key);
+}
+
+
+DEFINE_NATIVE_ENTRY(WeakProperty_getValue, 1) {
+  GET_NATIVE_ARGUMENT(WeakProperty, weak_property, arguments->At(0));
+  const Object& value = Object::Handle(weak_property.value());
+  arguments->SetReturn(value);
+}
+
+}  // namespace dart