Reland "Allow compaction when incremental marking is on."

src/heap/incremental-marking.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_INCREMENTAL_MARKING_H_
 #define V8_HEAP_INCREMENTAL_MARKING_H_
 
 
 #include "src/execution.h"
 #include "src/heap/mark-compact.h"
@@ skipping 49 matching lines @@
   }
 
   GCRequestType request_type() const { return request_type_; }
 
   bool WorthActivating();
 
   bool ShouldActivate();
 
   bool WasActivated();
 
-  enum CompactionFlag { ALLOW_COMPACTION, PREVENT_COMPACTION };
-
-  void Start(CompactionFlag flag = ALLOW_COMPACTION);
+  void Start();
 
   void Stop();
 
   void MarkObjectGroups();
 
   void PrepareForScavenge();
 
   void UpdateMarkingDequeAfterScavenge();
 
   void Hurry();
@@ skipping 118 matching lines @@
 
   Heap* heap() const { return heap_; }
 
  private:
   int64_t SpaceLeftInOldSpace();
 
   void SpeedUp();
 
   void ResetStepCounters();
 
-  void StartMarking(CompactionFlag flag);
+  void StartMarking();
 
   void ActivateIncrementalWriteBarrier(PagedSpace* space);
   static void ActivateIncrementalWriteBarrier(NewSpace* space);
   void ActivateIncrementalWriteBarrier();
 
   static void DeactivateIncrementalWriteBarrierForSpace(PagedSpace* space);
   static void DeactivateIncrementalWriteBarrierForSpace(NewSpace* space);
   void DeactivateIncrementalWriteBarrier();
 
   static void SetOldSpacePageFlags(MemoryChunk* chunk, bool is_marking,
@@ skipping 36 matching lines @@
   int weak_closure_approximation_rounds_;
 
   GCRequestType request_type_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncrementalMarking);
 };
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_INCREMENTAL_MARKING_H_