Re-evaluate marking bits of a descriptor array when it gets replaced.

src/objects.cc

 // Copyright 2013 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 2561 matching lines @@
     if (transition != TransitionArray::kNotFound) {
       transitions->GetTarget(transition)->DeprecateTransitionTree();
     }
   }
 
   // Don't overwrite the empty descriptor array.
   if (NumberOfOwnDescriptors() == 0) return;
 
   DescriptorArray* to_replace = instance_descriptors();
   Map* current = this;
+  GetHeap()->incremental_marking()->RecordWrites(to_replace);
   while (current->instance_descriptors() == to_replace) {
     current->SetEnumLength(kInvalidEnumCacheSentinel);
     current->set_instance_descriptors(new_descriptors);
     Object* next = current->GetBackPointer();
     if (next->IsUndefined()) break;
     current = Map::cast(next);
   }
 
   set_owns_descriptors(false);
 }
@@ skipping 4215 matching lines @@
       // that the maps to which we push the new descriptor array back can rely
       // on a cache always being available once it is set. If the map has more
       // enumerated descriptors than available in the original cache, the cache
       // will be lazily replaced by the extended cache when needed.
       if (descriptors->HasEnumCache()) {
         new_descriptors->CopyEnumCacheFrom(descriptors);
       }
 
       Map* map;
       // Replace descriptors by new_descriptors in all maps that share it.
+
+      GetHeap()->incremental_marking()->RecordWrites(descriptors);
       for (Object* current = GetBackPointer();
            !current->IsUndefined();
            current = map->GetBackPointer()) {
         map = Map::cast(current);
         if (map->instance_descriptors() != descriptors) break;
         map->set_instance_descriptors(new_descriptors);
       }
 
       set_instance_descriptors(new_descriptors);
     }
@@ skipping 9654 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal