Use idle task to perform incremental marking steps.

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/cancelable-task.h"
 #include "src/execution.h"
+#include "src/heap/incremental-marking-job.h"
 #include "src/heap/mark-compact.h"
 #include "src/objects.h"
 
 namespace v8 {
 namespace internal {
 
-
 class IncrementalMarking {
  public:
   enum State { STOPPED, SWEEPING, MARKING, COMPLETE };
 
   enum CompletionAction { GC_VIA_STACK_GUARD, NO_GC_VIA_STACK_GUARD };
 
   enum ForceMarkingAction { FORCE_MARKING, DO_NOT_FORCE_MARKING };
 
   enum ForceCompletionAction { FORCE_COMPLETION, DO_NOT_FORCE_COMPLETION };
 
@@ skipping 164 matching lines @@
   }
 
   void ClearIdleMarkingDelayCounter();
 
   bool IsIdleMarkingDelayCounterLimitReached();
 
   INLINE(static void MarkObject(Heap* heap, HeapObject* object));
 
   Heap* heap() const { return heap_; }
 
+  IncrementalMarkingJob* incremental_marking_job() {
+    return &incremental_marking_job_;
+  }
+
  private:
   int64_t SpaceLeftInOldSpace();
 
   void SpeedUp();
 
   void ResetStepCounters();
 
   void StartMarking();
 
   void ActivateIncrementalWriteBarrier(PagedSpace* space);
@@ skipping 38 matching lines @@
   int unscanned_bytes_of_large_object_;
 
   bool was_activated_;
 
   bool weak_closure_was_overapproximated_;
 
   int weak_closure_approximation_rounds_;
 
   GCRequestType request_type_;
 
+  IncrementalMarkingJob incremental_marking_job_;
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncrementalMarking);
 };
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_INCREMENTAL_MARKING_H_