Fix invariant so that we cannot record relocation slots for

src/incremental-marking-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 30 matching lines @@
   if (Marking::IsWhite(value_bit)) {
     MarkBit obj_bit = Marking::MarkBitFrom(obj);
     if (Marking::IsBlack(obj_bit)) {
       BlackToGreyAndUnshift(obj, obj_bit);
       RestartIfNotMarking();
     }
 
     // Object is either grey or white.  It will be scanned if survives.
     return false;
   }
-  return true;
+  if (!is_compacting_) return false;
+  MarkBit obj_bit = Marking::MarkBitFrom(obj);
+  return Marking::IsBlack(obj_bit);
 }
 
 
 void IncrementalMarking::RecordWrite(HeapObject* obj,
                                      Object** slot,
                                      Object* value) {
   if (IsMarking() && value->NonFailureIsHeapObject()) {
     RecordWriteSlow(obj, slot, value);
   }
 }
@@ skipping 78 matching lines @@
     MemoryChunk::IncrementLiveBytesFromGC(obj->address(), obj->Size());
     return true;
   }
   return false;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_INCREMENTAL_MARKING_INL_H_