[heap] Make survival counters concurrent (atomic)

src/heap/mark-compact.cc

Index: src/heap/mark-compact.cc
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index 65bfdd92d871a262e517452c8c14fe0989482d9b..0b331e33f30e59fb7b29e3d178fb049c0dc0d401 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -3100,13 +3100,12 @@ HashMap* MarkCompactCollector::EvacuateNewSpaceInParallel() {
     USE(ok);
     DCHECK(ok);
   }
-  heap_->IncrementPromotedObjectsSize(
-      static_cast<int>(new_space_visitor.promoted_size()));
+  heap_->IncrementPromotedObjectsSize(new_space_visitor.promoted_size());
   heap_->IncrementSemiSpaceCopiedObjectSize(
-      static_cast<int>(new_space_visitor.semispace_copied_size()));
+      new_space_visitor.semispace_copied_size());
   heap_->IncrementYoungSurvivorsCounter(
-      static_cast<int>(new_space_visitor.promoted_size()) +
-      static_cast<int>(new_space_visitor.semispace_copied_size()));
+      new_space_visitor.promoted_size() +
+      new_space_visitor.semispace_copied_size());
   return local_pretenuring_feedback;
 }