Put preservation of optimized code map behind a flag.

src/objects-visiting-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 293 matching lines @@
 
 
 template<typename StaticVisitor>
 void StaticMarkingVisitor<StaticVisitor>::VisitSharedFunctionInfo(
     Map* map, HeapObject* object) {
   Heap* heap = map->GetHeap();
   SharedFunctionInfo* shared = SharedFunctionInfo::cast(object);
   if (shared->ic_age() != heap->global_ic_age()) {
     shared->ResetForNewContext(heap->global_ic_age());
   }
+  if (FLAG_cache_optimized_code &&
+      FLAG_flush_optimized_code_cache &&
+      !shared->optimized_code_map()->IsSmi()) {
+    // Always flush the optimized code map if requested by flag.
+    shared->ClearOptimizedCodeMap();
+  }
   MarkCompactCollector* collector = heap->mark_compact_collector();
   if (collector->is_code_flushing_enabled()) {
     if (FLAG_cache_optimized_code && !shared->optimized_code_map()->IsSmi()) {
       // Add the shared function info holding an optimized code map to
       // the code flusher for processing of code maps after marking.
       collector->code_flusher()->AddOptimizedCodeMap(shared);
       // Treat all references within the code map weakly by marking the
       // code map itself but not pushing it onto the marking deque.
       FixedArray* code_map = FixedArray::cast(shared->optimized_code_map());
       StaticVisitor::MarkObjectWithoutPush(heap, code_map);
@@ skipping 415 matching lines @@
   RelocIterator it(this, mode_mask);
   for (; !it.done(); it.next()) {
     it.rinfo()->template Visit<StaticVisitor>(heap);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_VISITING_INL_H_