Refactor Map::ConstructionCount.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 7ba756ed2ebcf7e19897667f0d6a26c61242c08c..aaab6fd08725441cf159da1fdffa99735e7bbdec 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -4627,24 +4627,12 @@ bool Map::is_migration_target() {
 }
 
 
-void Map::set_done_inobject_slack_tracking(bool value) {
-  set_bit_field3(DoneInobjectSlackTracking::update(bit_field3(), value));
+void Map::set_counter(int value) {
+  set_bit_field3(Counter::update(bit_field3(), value));
 }
 
 
-bool Map::done_inobject_slack_tracking() {
-  return DoneInobjectSlackTracking::decode(bit_field3());
-}
-
-
-void Map::set_construction_count(int value) {
-  set_bit_field3(ConstructionCount::update(bit_field3(), value));
-}
-
-
-int Map::construction_count() {
-  return ConstructionCount::decode(bit_field3());
-}
+int Map::counter() { return Counter::decode(bit_field3()); }
 
 
 void Map::freeze() {
@@ -6051,7 +6039,7 @@ bool JSFunction::IsInOptimizationQueue() {
 
 bool JSFunction::IsInobjectSlackTrackingInProgress() {
   return has_initial_map() &&
-      initial_map()->construction_count() != JSFunction::kNoSlackTracking;
+         initial_map()->counter() >= Map::kSlackTrackingCounterEnd;
 }