[heap] Start concurrent marking simultaneously with incremental marking.

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 ab38efbca55e3aa07857eba71ed539cb3b06968f..ce52018e29057a3e17469eb1aa3844731f5e617e 100644
--- a/test/cctest/heap/test-concurrent-marking.cc
+++ b/test/cctest/heap/test-concurrent-marking.cc
@@ -15,12 +15,12 @@
 namespace v8 {
 namespace internal {
 TEST(ConcurrentMarking) {
-  i::FLAG_concurrent_marking = true;
+  if (!i::FLAG_concurrent_marking) return;
   CcTest::InitializeVM();
   Heap* heap = CcTest::heap();
   ConcurrentMarking* concurrent_marking = new ConcurrentMarking(heap);
   concurrent_marking->AddRoot(heap->undefined_value());
-  concurrent_marking->StartMarkingTask();
+  concurrent_marking->StartTask();
   concurrent_marking->WaitForTaskToComplete();
   delete concurrent_marking;
 }