Release evacuation candidates after parallel sweeper threads completed.

src/mark-compact.h

Index: src/mark-compact.h
diff --git a/src/mark-compact.h b/src/mark-compact.h
index 7a328576508f092c228e72f77534cd4b7ffe03ff..ca4cecda1f85915a27df003f4edc234856837beb 100644
--- a/src/mark-compact.h
+++ b/src/mark-compact.h
@@ -686,7 +686,7 @@ class MarkCompactCollector {
                        FreeList* private_free_list,
                        FreeList* free_list);
 
-  void WaitUntilSweepingCompleted();
+  bool WaitUntilSweepingCompleted();
 
   intptr_t StealMemoryFromSweeperThreads(PagedSpace* space);
 
@@ -694,6 +694,8 @@ class MarkCompactCollector {
 
   bool IsConcurrentSweepingInProgress();
 
+  void FinalizeSweeping();
+
   // Parallel marking support.
   void MarkInParallel();
 
@@ -707,6 +709,8 @@ class MarkCompactCollector {
   void RemoveDeadInvalidatedCode();
   void ProcessInvalidatedCode(ObjectVisitor* visitor);
 
+  void ReleaseEvacuationCandidates();
+
   void StartSweeperThreads();
 
 #ifdef DEBUG