[Heap] Remove concept of MarkingParity.

src/heap/mark-compact.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_MARK_COMPACT_H_
 #define V8_HEAP_MARK_COMPACT_H_
 
 #include <deque>
 
 #include "src/base/bits.h"
@@ skipping 466 matching lines @@
 
   void UpdateSlots(SlotsBuffer* buffer);
   void UpdateSlotsRecordedIn(SlotsBuffer* buffer);
 
   void InvalidateCode(Code* code);
 
   void ClearMarkbits();
 
   bool is_compacting() const { return compacting_; }
 
-  MarkingParity marking_parity() { return marking_parity_; }
-
   // Ensures that sweeping is finished.
   //
   // Note: Can only be called safely from main thread.
   void EnsureSweepingCompleted();
 
   // Help out in sweeping the corresponding space and refill memory that has
   // been regained.
   //
   // Note: Thread-safe.
   void SweepAndRefill(CompactionSpace* space);
@@ skipping 240 matching lines @@
     SWEEP_SPACES,
     ENCODE_FORWARDING_ADDRESSES,
     UPDATE_POINTERS,
     RELOCATE_OBJECTS
   };
 
   // The current stage of the collector.
   CollectorState state_;
 #endif
 
-  MarkingParity marking_parity_;
-
   bool was_marked_incrementally_;
 
   bool evacuation_;
 
   // True if we are collecting slots to perform evacuation from evacuation
   // candidates.
   bool compacting_;
 
   bool black_allocation_;
 
@@ skipping 24 matching lines @@
 
  private:
   MarkCompactCollector* collector_;
 };
 
 V8_EXPORT_PRIVATE const char* AllocationSpaceName(AllocationSpace space);
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_MARK_COMPACT_H_