Implemented Object.keys.

src/handles.h

Index: src/handles.h
diff --git a/src/handles.h b/src/handles.h
index 847aebb3b2181eb7ad794d2179ef016607cab1ac..5d574657c5f0505346cd6fedb6f63bde1b8388c2 100644
--- a/src/handles.h
+++ b/src/handles.h
@@ -265,9 +265,13 @@ v8::Handle<v8::Array> GetKeysForNamedInterceptor(Handle<JSObject> receiver,
                                                  Handle<JSObject> object);
 v8::Handle<v8::Array> GetKeysForIndexedInterceptor(Handle<JSObject> receiver,
                                                    Handle<JSObject> object);
+
+enum KeyCollectionType { LOCAL_ONLY, INCLUDE_PROTOS };
+
 // Computes the enumerable keys for a JSObject. Used for implementing
 // "for (n in object) { }".
-Handle<FixedArray> GetKeysInFixedArrayFor(Handle<JSObject> object);
+Handle<FixedArray> GetKeysInFixedArrayFor(Handle<JSObject> object,
+                                          KeyCollectionType type);
 Handle<JSArray> GetKeysFor(Handle<JSObject> object);
 Handle<FixedArray> GetEnumPropertyKeys(Handle<JSObject> object);