Use incremental marking deque in idle notification.

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 128 matching lines @@
   inline void SetOldSpacePageFlags(MemoryChunk* chunk) {
     SetOldSpacePageFlags(chunk, IsMarking(), IsCompacting());
   }
 
   inline void SetNewSpacePageFlags(NewSpacePage* chunk) {
     SetNewSpacePageFlags(chunk, IsMarking());
   }
 
   MarkingDeque* marking_deque() { return &marking_deque_; }
 
+  bool IsMarkingDequeEmpty() { return marking_deque_.IsEmpty(); }
+
   bool IsCompacting() { return IsMarking() && is_compacting_; }
 
   void ActivateGeneratedStub(Code* stub);
 
   void NotifyOfHighPromotionRate() {
     if (IsMarking()) {
       if (marking_speed_ < kFastMarking) {
         if (FLAG_trace_gc) {
           PrintPID(
               "Increasing marking speed to %d "
@@ skipping 74 matching lines @@
   int no_marking_scope_depth_;
 
   int unscanned_bytes_of_large_object_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncrementalMarking);
 };
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_INCREMENTAL_MARKING_H_