api: Object::CachedProperty

src/property.h

Index: src/property.h
diff --git a/src/property.h b/src/property.h
index 229241948a8c4ee0dc253e199bdbd1710fdb8159..a1c46a69bab6f877de4aba7ebd3effc09ad6dc51 100644
--- a/src/property.h
+++ b/src/property.h
@@ -207,6 +207,15 @@ class LookupResult BASE_EMBEDDED {
 
   Isolate* isolate() const { return isolate_; }
 
+  void CopyFrom(LookupResult* res, JSObject* new_holder) {
+    isolate_ = res->isolate_;
+    lookup_type_ = res->lookup_type_;
+    number_ = res->number_;
+    cacheable_ = res->cacheable_;
+    details_ = res->details_;
+    holder_ = new_holder;
+  }
+
   void DescriptorResult(JSObject* holder, PropertyDetails details, int number) {
     lookup_type_ = DESCRIPTOR_TYPE;
     holder_ = holder;
@@ -475,7 +484,7 @@ class LookupResult BASE_EMBEDDED {
 
   void Iterate(ObjectVisitor* visitor);
 
- private:
+ protected:
   Isolate* isolate_;
   LookupResult* next_;