Make 'Become' safe for retries.

src/heap.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 1667 matching lines @@
   void MarkCompactPrologue();
 
   // Record statistics before and after garbage collection.
   void ReportStatisticsBeforeGC();
   void ReportStatisticsAfterGC();
 
   // Slow part of scavenge object.
   static void ScavengeObjectSlow(HeapObject** p, HeapObject* object);
 
   // Initializes a function with a shared part and prototype.
-  // Returns the function.
   // Note: this code was factored out of AllocateFunction such that
   // other parts of the VM could use it. Specifically, a function that creates
   // instances of type JS_FUNCTION_TYPE benefit from the use of this function.
   // Please note this does not perform a garbage collection.
-  MUST_USE_RESULT inline MaybeObject* InitializeFunction(
+  inline void InitializeFunction(
       JSFunction* function,
       SharedFunctionInfo* shared,
       Object* prototype);
 
   // Total RegExp code ever generated
   double total_regexp_code_generated_;
 
   GCTracer* tracer_;
 
 
@@ skipping 780 matching lines @@
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG || LIVE_OBJECT_LIST
 
 } }  // namespace v8::internal
 
 #undef HEAP
 
 #endif  // V8_HEAP_H_