[heap] Remove unused flag prohibiting local slot buffer entries

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 "src/base/bits.h"
 #include "src/heap/spaces.h"
 #include "src/heap/store-buffer.h"
@@ skipping 749 matching lines @@
   SweepingList sweeping_list_code_space_;
   SweepingList sweeping_list_map_space_;
 
   // True if we are collecting slots to perform evacuation from evacuation
   // candidates.
   bool compacting_;
 
   // True if concurrent or parallel sweeping is currently in progress.
   bool sweeping_in_progress_;
 
-  // True if parallel compaction is currently in progress.
-  bool compaction_in_progress_;
-
   // Semaphore used to synchronize sweeper tasks.
   base::Semaphore pending_sweeper_tasks_semaphore_;
 
   // Semaphore used to synchronize compaction tasks.
   base::Semaphore pending_compaction_tasks_semaphore_;
 
   friend class Heap;
   friend class StoreBuffer;
 };
 
@@ skipping 79 matching lines @@
  private:
   MarkCompactCollector* collector_;
 };
 
 
 const char* AllocationSpaceName(AllocationSpace space);
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_MARK_COMPACT_H_