Preserve marking bits across scavenges if incremental marker is running.

src/objects-visiting.h

 // Copyright 2006-2009 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 124 matching lines @@
         base + (object_size >> kPointerSizeLog2) - kMinObjectSizeInWords);
 
     return Min(specialization, generic);
   }
 };
 
 
 template<typename Callback>
 class VisitorDispatchTable {
  public:
+  void CopyFrom(VisitorDispatchTable* other) {
+    memcpy(callbacks_,
+           other->callbacks_,
+           kPointerSize*StaticVisitorBase::kVisitorIdCount);
+  }
+
   inline Callback GetVisitor(Map* map) {
     return callbacks_[map->visitor_id()];
   }
 
   void Register(StaticVisitorBase::VisitorId id, Callback callback) {
     ASSERT(id < StaticVisitorBase::kVisitorIdCount);  // id is unsigned.
     callbacks_[id] = callback;
   }
 
   template<typename Visitor,
@@ skipping 238 matching lines @@
 
   for (; !it.done(); it.next()) {
     it.rinfo()->template Visit<StaticVisitor>();
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_VISITING_H_