[heap] inline allocation steps refactor

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index c3dd5d3625ee46d57f5fb0d8608fdaa44c9233d8..e6588d11b7dbc822e454c33360b46aac443fa434 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -1899,13 +1899,6 @@ class Heap {
                                        double mutator_speed);
 
   // ===========================================================================
-  // Inline allocation. ========================================================
-  // ===========================================================================
-
-  void LowerInlineAllocationLimit(intptr_t step);
-  void ResetInlineAllocationLimit();
-
-  // ===========================================================================
   // Idle notification. ========================================================
   // ===========================================================================
 
@@ -2292,6 +2285,8 @@ class Heap {
 
   ScavengeJob* scavenge_job_;
 
+  InlineAllocationObserver* idle_scavenge_observer_;
+
   // These two counters are monotomically increasing and never reset.
   size_t full_codegen_bytes_generated_;
   size_t crankshaft_codegen_bytes_generated_;
@@ -2362,6 +2357,7 @@ class Heap {
   friend class GCCallbacksScope;
   friend class GCTracer;
   friend class HeapIterator;
+  friend class IdleScavengeObserver;
   friend class IncrementalMarking;
   friend class MarkCompactCollector;
   friend class MarkCompactMarkingVisitor;