Clean-up and repair cumulative marking and sweeping time stats.

src/incremental-marking.cc

Index: src/incremental-marking.cc
diff --git a/src/incremental-marking.cc b/src/incremental-marking.cc
index 0ab9a002452e94aa7846816d14c73e9c4f349b7e..1651234d0f827d5a367455738ed40955d9d1ef3e 100644
--- a/src/incremental-marking.cc
+++ b/src/incremental-marking.cc
@@ -729,7 +729,7 @@ void IncrementalMarking::Hurry() {
     if (FLAG_trace_incremental_marking || FLAG_print_cumulative_gc_stat) {
       double end = base::OS::TimeCurrentMillis();
       double delta = end - start;
-      heap_->AddMarkingTime(delta);
+      heap_->tracer()->AddMarkingTime(delta);
       if (FLAG_trace_incremental_marking) {
         PrintF("[IncrementalMarking] Complete (hurry), spent %d ms.\n",
                static_cast<int>(delta));
@@ -957,7 +957,6 @@ void IncrementalMarking::Step(intptr_t allocated_bytes,
     double end = base::OS::TimeCurrentMillis();
     double duration = (end - start);
     heap_->tracer()->AddIncrementalMarkingStep(duration, allocated_bytes);
-    heap_->AddMarkingTime(duration);
   }
 }