Remove special handling of background idle notification in memory reducer.

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index b0f03e00f56cb4df6f8cb6c3f07be5c37fee0557..4855f74ee0c79f19df250768403c22637837907e 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -1788,8 +1788,7 @@ class Heap {
   void IdleNotificationEpilogue(GCIdleTimeAction action,
                                 GCIdleTimeHeapState heap_state, double start_ms,
                                 double deadline_in_ms);
-  void CheckAndNotifyBackgroundIdleNotification(double idle_time_in_ms,
-                                                double now_ms);
+  void CheckBackgroundIdleNotification(double idle_time_in_ms, double now_ms);
 
   inline void UpdateAllocationsHash(HeapObject* object);
   inline void UpdateAllocationsHash(uint32_t value);