Refactoring only: Make the handling of PropertyType more explicit.

src/property.h

 // Copyright 2011 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 274 matching lines @@
         }
         return value;
       }
       case CONSTANT_FUNCTION:
         return GetConstantFunction();
       default:
         return Smi::FromInt(0);
     }
   }
 
+
   Map* GetTransitionMap() {
     ASSERT(lookup_type_ == DESCRIPTOR_TYPE);
-    ASSERT(type() == MAP_TRANSITION || type() == CONSTANT_TRANSITION ||
-           type() == ELEMENTS_TRANSITION);
+    ASSERT(IsTransitionType(type()));
     return Map::cast(GetValue());
   }
 
   Map* GetTransitionMapFromMap(Map* map) {
     ASSERT(lookup_type_ == DESCRIPTOR_TYPE);
     ASSERT(type() == MAP_TRANSITION);
     return Map::cast(map->instance_descriptors()->GetValue(number_));
   }
 
   int GetFieldIndex() {
@@ skipping 67 matching lines @@
   JSReceiver* holder_;
   int number_;
   bool cacheable_;
   PropertyDetails details_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_PROPERTY_H_