DescriptorArray::CopyFrom should always drop transitions for CALLBACKS.

src/objects-inl.h

 // 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 2035 matching lines @@
   FixedArray* content_array = GetContentArray();
   NoIncrementalWriteBarrierSet(content_array,
                                ToValueIndex(descriptor_number),
                                desc->GetValue());
   NoIncrementalWriteBarrierSet(content_array,
                                ToDetailsIndex(descriptor_number),
                                desc->GetDetails().AsSmi());
 }
 
 
-void DescriptorArray::CopyFrom(int index,
-                               DescriptorArray* src,
-                               int src_index,
-                               const WhitenessWitness& witness) {
-  Descriptor desc;
-  src->Get(src_index, &desc);
-  Set(index, &desc, witness);
-}
-
-
 void DescriptorArray::NoIncrementalWriteBarrierSwapDescriptors(
     int first, int second) {
   NoIncrementalWriteBarrierSwap(this, ToKeyIndex(first), ToKeyIndex(second));
   FixedArray* content_array = GetContentArray();
   NoIncrementalWriteBarrierSwap(content_array,
                                 ToValueIndex(first),
                                 ToValueIndex(second));
   NoIncrementalWriteBarrierSwap(content_array,
                                 ToDetailsIndex(first),
                                 ToDetailsIndex(second));
@@ skipping 2829 matching lines @@
 #undef WRITE_INT_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_