Switch UnreachableObjectsFilter to use Marking instead of InstrusiveMarking.

src/mark-compact.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 520 matching lines @@
 
   bool TryPromoteObject(HeapObject* object, int object_size);
 
   inline Object* encountered_weak_maps() { return encountered_weak_maps_; }
   inline void set_encountered_weak_maps(Object* weak_map) {
     encountered_weak_maps_ = weak_map;
   }
 
   void InvalidateCode(Code* code);
 
+  void ClearMarkbits();
+
  private:
   MarkCompactCollector();
   ~MarkCompactCollector();
 
   bool MarkInvalidatedCode();
   void RemoveDeadInvalidatedCode();
   void ProcessInvalidatedCode(ObjectVisitor* visitor);
 
 
 #ifdef DEBUG
@@ skipping 159 matching lines @@
   void EvacuateNewSpace();
 
   void EvacuateLiveObjectsFromPage(Page* p);
 
   void EvacuatePages();
 
   void EvacuateNewSpaceAndCandidates();
 
   void SweepSpace(PagedSpace* space, SweeperType sweeper);
 
-
 #ifdef DEBUG
   // -----------------------------------------------------------------------
   // Debugging variables, functions and classes
   // Counters used for debugging the marking phase of mark-compact or
   // mark-sweep collection.
 
   // Size of live objects in Heap::to_space_.
   int live_young_objects_size_;
 
   // Size of live objects in Heap::old_pointer_space_.
@@ skipping 34 matching lines @@
 
   friend class Heap;
 };
 
 
 const char* AllocationSpaceName(AllocationSpace space);
 
 } }  // namespace v8::internal
 
 #endif  // V8_MARK_COMPACT_H_