- Removed the kWatchedBit and the associated weak property handling

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 60e35500e4ab80adfbce2746a66d2f1e9fb84e4a..1565744deda2faabd72e893da782bda296aa459a 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -22259,7 +22259,9 @@ RawWeakProperty* WeakProperty::New(Heap::Space space) {
   RawObject* raw = Object::Allocate(WeakProperty::kClassId,
                                     WeakProperty::InstanceSize(),
                                     space);
-  return reinterpret_cast<RawWeakProperty*>(raw);
+  RawWeakProperty* result = reinterpret_cast<RawWeakProperty*>(raw);
+  result->ptr()->next_ = 0;  // Init the list to NULL.
+  return result;
 }