Wait for sweeper threads in incremental marking step when sweeper threads are done sweeping.

src/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_MARK_COMPACT_H_
 #define V8_MARK_COMPACT_H_
 
 #include "compiler-intrinsics.h"
 #include "spaces.h"
 
@@ skipping 653 matching lines @@
 
   bool is_compacting() const { return compacting_; }
 
   MarkingParity marking_parity() { return marking_parity_; }
 
   // Concurrent and parallel sweeping support.
   void SweepInParallel(PagedSpace* space);
 
   void WaitUntilSweepingCompleted();
 
+  bool IsSweepingCompleted();
+
   void RefillFreeList(PagedSpace* space);
 
   bool AreSweeperThreadsActivated();
 
   bool IsConcurrentSweepingInProgress();
 
   void set_sequential_sweeping(bool sequential_sweeping) {
     sequential_sweeping_ = sequential_sweeping;
   }
 
@@ skipping 304 matching lines @@
  private:
   MarkCompactCollector* collector_;
 };
 
 
 const char* AllocationSpaceName(AllocationSpace space);
 
 } }  // namespace v8::internal
 
 #endif  // V8_MARK_COMPACT_H_