Preserve marking bits across scavenges if incremental marker is running.

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 1455 matching lines @@
   }
 
   static bool IsIncreasingSurvivalTrend() {
     return survival_rate_trend() == INCREASING;
   }
 
   static bool IsHighSurvivalRate() {
     return high_survival_rate_period_length_ > 0;
   }
 
+  static void SelectScavengingVisitorsTable();
+
   static const int kInitialSymbolTableSize = 2048;
   static const int kInitialEvalCacheSize = 64;
 
   friend class Factory;
   friend class DisallowAllocationFailure;
   friend class AlwaysAllocateScope;
   friend class LinearAllocationScope;
   friend class MarkCompactCollector;
 };
 
@@ skipping 298 matching lines @@
     }
   }
 
   HeapObject* Pop() {
     ASSERT(!is_empty());
     HeapObject* object = *(--top_);
     ASSERT(object->IsHeapObject());
     return object;
   }
 
+  HeapObject** low() { return low_; }
+  HeapObject** top() { return top_; }
+  void set_top(HeapObject** top) { top_ = top; }
+
  private:
   HeapObject** low_;
   HeapObject** top_;
   HeapObject** high_;
   bool overflowed_;
 };
 
 
 // A helper class to document/test C++ scopes where we do not
 // expect a GC. Usage:
@@ skipping 435 matching lines @@
 
   AssertNoAllocation no_alloc;  // i.e. no gc allowed.
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG || LIVE_OBJECT_LIST
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_