Gcstress bug fix: Transition arrays may get smaller during gc.

src/transitions.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 77 matching lines @@
 
   // Returns the number of transitions in the array.
   int number_of_transitions() {
     if (IsSimpleTransition()) return 1;
     int len = length();
     return len <= kFirstIndex ? 0 : (len - kFirstIndex) / kTransitionSize;
   }
 
   inline int number_of_entries() { return number_of_transitions(); }
 
+  // Creates a FullTransitionArray from a SimpleTransitionArray in
+  // containing_map.
   static Handle<TransitionArray> ExtendToFullTransitionArray(
-      Handle<TransitionArray> array);
+      Handle<Map> containing_map);
 
   // Create a transition array, copying from the owning map if it already has
   // one, otherwise creating a new one according to flag.
   // TODO(verwaest): This should not cause an existing transition to be
   // overwritten.
   static Handle<TransitionArray> CopyInsert(Handle<Map> map,
                                             Handle<Name> name,
                                             Handle<Map> target,
                                             SimpleTransitionFlag flag);
 
@@ skipping 99 matching lines @@
                                                 int origin_transition,
                                                 int target_transition);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(TransitionArray);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TRANSITIONS_H_