Revert of GC: Refactor public incremental marking interface in heap

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index eae80d1d66c79b24c745d126eb19eaee95875554..750827968dcd757edff47ece2ed0948930aa688f 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -852,21 +852,6 @@
   // incremental steps.
   void StartIdleIncrementalMarking();
 
-  // Starts incremental marking assuming incremental marking is currently
-  // stopped.
-  void StartIncrementalMarking(int gc_flags,
-                               const GCCallbackFlags gc_callback_flags,
-                               const char* reason = nullptr);
-
-  // Performs incremental marking steps of step_size_in_bytes as long as
-  // deadline_ins_ms is not reached. step_size_in_bytes can be 0 to compute
-  // an estimate increment. Returns the remaining time that cannot be used
-  // for incremental marking anymore because a single step would exceed the
-  // deadline.
-  double AdvanceIncrementalMarking(
-      intptr_t step_size_in_bytes, double deadline_in_ms,
-      IncrementalMarking::StepActions step_actions);
-
   inline void increment_scan_on_scavenge_pages() {
     scan_on_scavenge_pages_++;
     if (FLAG_gc_verbose) {
@@ -2246,6 +2231,10 @@
       size_t mark_compact_speed_in_bytes_per_ms);
 
   GCIdleTimeHandler::HeapState ComputeHeapState();
+
+  double AdvanceIncrementalMarking(
+      intptr_t step_size_in_bytes, double deadline_in_ms,
+      IncrementalMarking::ForceCompletionAction completion);
 
   bool PerformIdleTimeAction(GCIdleTimeAction action,
                              GCIdleTimeHandler::HeapState heap_state,