- Optimized JSArray allocation in runtime system by using NewJSArrayWithEleme...

src/handles.cc

Index: src/handles.cc
===================================================================
--- src/handles.cc	(revision 478)
+++ src/handles.cc	(working copy)
@@ -391,13 +391,8 @@
 
 Handle<JSArray> GetKeysFor(Handle<JSObject> object) {
   Counters::for_in.Increment();
-
-  Handle<FixedArray> content = GetKeysInFixedArrayFor(object);
-
-  // Allocate the JSArray with the result.
-  Handle<JSArray> obj = Factory::NewJSArray(content->length());
-  Handle<JSArray>::cast(obj)->SetContent(*content);
-  return Handle<JSArray>::cast(obj);
+  Handle<FixedArray> elements = GetKeysInFixedArrayFor(object);
+  return Factory::NewJSArrayWithElements(elements);
 }