Do not generate new enumeration indices for global objects.

src/handles.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 773 matching lines @@
     // properties were not visible, the array is trimmed so it only contains
     // visible properties. This improves over adding elements and sorting by
     // index by having linear complexity rather than n*log(n).
 
     // By comparing the monotonous NextEnumerationIndex to the NumberOfElements,
     // we can predict the number of holes in the final array. If there will be
     // more than 50% holes, regenerate the enumeration indices to reduce the
     // number of holes to a minimum. This avoids allocating a large array if
     // many properties were added but subsequently deleted.
     int next_enumeration = dictionary->NextEnumerationIndex();
-    if (next_enumeration > (length * 3) / 2) {
+    if (!object->IsGlobalObject() && next_enumeration > (length * 3) / 2) {
       StringDictionary::DoGenerateNewEnumerationIndices(dictionary);
       next_enumeration = dictionary->NextEnumerationIndex();
     }
 
     Handle<FixedArray> storage =
         isolate->factory()->NewFixedArray(next_enumeration);
 
     storage = Handle<FixedArray>(dictionary->CopyEnumKeysTo(*storage));
     ASSERT(storage->length() == object->NumberOfLocalProperties(DONT_ENUM));
     return storage;
@@ skipping 221 matching lines @@
   data->next = prev_next_;
   data->limit = prev_limit_;
 #ifdef DEBUG
   handles_detached_ = true;
 #endif
   return deferred;
 }
 
 
 } }  // namespace v8::internal