Remove sweeper threads

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"
 
@@ skipping 623 matching lines @@
 
   void EnsureSweepingCompleted();
 
   // If sweeper threads are not active this method will return true. If
   // this is a latency issue we should be smarter here. Otherwise, it will
   // return true if the sweeper threads are done processing the pages.
   bool IsSweepingCompleted();
 
   void RefillFreeList(PagedSpace* space);
 
-  bool AreSweeperThreadsActivated();
-
   // Checks if sweeping is in progress right now on any space.
   bool sweeping_in_progress() { return sweeping_in_progress_; }
 
   void set_sequential_sweeping(bool sequential_sweeping) {
     sequential_sweeping_ = sequential_sweeping;
   }
 
   bool sequential_sweeping() const { return sequential_sweeping_; }
 
   // Mark the global table which maps weak objects to dependent code without
@@ skipping 291 matching lines @@
  private:
   MarkCompactCollector* collector_;
 };
 
 
 const char* AllocationSpaceName(AllocationSpace space);
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_MARK_COMPACT_H_