[heap] Do more incremental marking work in tasks.

test/cctest/heap/heap-utils.cc

Index: test/cctest/heap/heap-utils.cc
diff --git a/test/cctest/heap/heap-utils.cc b/test/cctest/heap/heap-utils.cc
index ad94d2c734770bd6bd0c853fa0e032856333d747..4f7d088a9462bdb17e3e9cddde0284d1139e2cb3 100644
--- a/test/cctest/heap/heap-utils.cc
+++ b/test/cctest/heap/heap-utils.cc
@@ -161,7 +161,7 @@ void SimulateIncrementalMarking(i::Heap* heap, bool force_completion) {
 
   while (!marking->IsComplete()) {
     marking->Step(i::MB, i::IncrementalMarking::NO_GC_VIA_STACK_GUARD,
-                  i::IncrementalMarking::FORCE_COMPLETION);
+                  i::IncrementalMarking::FORCE_COMPLETION, i::StepOrigin::kV8);
     if (marking->IsReadyToOverApproximateWeakClosure()) {
       marking->FinalizeIncrementally();
     }