[heap] Implement simple concurrent marking deque.

test/cctest/heap/test-concurrent-marking.cc

Index: test/cctest/heap/test-concurrent-marking.cc
diff --git a/test/cctest/heap/test-concurrent-marking.cc b/test/cctest/heap/test-concurrent-marking.cc
index ce52018e29057a3e17469eb1aa3844731f5e617e..03ee6c4b8c5b494f3df9ea0a752280f32933e2f3 100644
--- a/test/cctest/heap/test-concurrent-marking.cc
+++ b/test/cctest/heap/test-concurrent-marking.cc
@@ -18,8 +18,9 @@ TEST(ConcurrentMarking) {
   if (!i::FLAG_concurrent_marking) return;
   CcTest::InitializeVM();
   Heap* heap = CcTest::heap();
-  ConcurrentMarking* concurrent_marking = new ConcurrentMarking(heap);
-  concurrent_marking->AddRoot(heap->undefined_value());
+  ConcurrentMarkingDeque deque(heap);
+  deque.Push(heap->undefined_value());
+  ConcurrentMarking* concurrent_marking = new ConcurrentMarking(heap, &deque);
   concurrent_marking->StartTask();
   concurrent_marking->WaitForTaskToComplete();
   delete concurrent_marking;