Get rid of the TRANSITION PropertyType and consistently use CanHoldValue().

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 2611 matching lines @@
   DescriptorArray* descriptors = this->instance_descriptors();
   int number = descriptors->SearchWithCache(name, this);
   if (number == DescriptorArray::kNotFound) return result->NotFound();
   result->DescriptorResult(holder, descriptors->GetDetails(number), number);
 }
 
 
 void Map::LookupTransition(JSObject* holder,
                            Name* name,
                            LookupResult* result) {
-  if (HasTransitionArray()) {
-    TransitionArray* transition_array = transitions();
-    int number = transition_array->Search(name);
-    if (number != TransitionArray::kNotFound) {
-      return result->TransitionResult(
-          holder, transition_array->GetTarget(number));
-    }
-  }
-  result->NotFound();
+  int transition_index = this->SearchTransition(name);
+  if (transition_index == TransitionArray::kNotFound) return result->NotFound();
+  result->TransitionResult(holder, this->GetTransition(transition_index));
 }
 
 
 Object** DescriptorArray::GetKeySlot(int descriptor_number) {
   ASSERT(descriptor_number < number_of_descriptors());
   return RawFieldOfElementAt(ToKeyIndex(descriptor_number));
 }
 
 
 Object** DescriptorArray::GetDescriptorStartSlot(int descriptor_number) {
@@ skipping 2246 matching lines @@
 void Map::SetTransition(int transition_index, Map* target) {
   transitions()->SetTarget(transition_index, target);
 }
 
 
 Map* Map::GetTransition(int transition_index) {
   return transitions()->GetTarget(transition_index);
 }
 
 
+int Map::SearchTransition(Name* name) {
+  if (HasTransitionArray()) return transitions()->Search(name);
+  return TransitionArray::kNotFound;
+}
+
+
 MaybeObject* Map::set_elements_transition_map(Map* transitioned_map) {
   TransitionArray* transitions;
   MaybeObject* maybe_transitions = AddTransition(
       GetHeap()->elements_transition_symbol(),
       transitioned_map,
       FULL_TRANSITION);
   if (!maybe_transitions->To(&transitions)) return maybe_transitions;
   set_transitions(transitions);
   return transitions;
 }
@@ skipping 2024 matching lines @@
 #undef READ_UINT32_FIELD
 #undef WRITE_UINT32_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_