Revert "Make more GCs in idle notification handler." because of performance

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index 394a02ad2c7c9fc2c8d7631bc0eddf27d511f8e8..6d044545164a059fb930178d4cd8b1071b341ac3 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -2261,6 +2261,7 @@ class Heap {
 
   void StartIdleRound() {
     mark_sweeps_since_idle_round_started_ = 0;
+    ms_count_at_last_idle_notification_ = ms_count_;
   }
 
   void FinishIdleRound() {
@@ -2337,6 +2338,7 @@ class Heap {
   bool last_idle_notification_gc_count_init_;
 
   int mark_sweeps_since_idle_round_started_;
+  int ms_count_at_last_idle_notification_;
   unsigned int gc_count_at_last_idle_gc_;
   int scavenges_since_last_idle_round_;