GC: Refactor public incremental marking interface in heap

src/heap/heap.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 #include <map>
 
@@ skipping 834 matching lines @@
   // Check whether the heap is currently iterable.
   bool IsHeapIterable();
 
   // Notify the heap that a context has been disposed.
   int NotifyContextDisposed(bool dependant_context);
 
   // Start incremental marking and ensure that idle time handler can perform
   // 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) {
       PrintF("Scan-on-scavenge pages: %d\n", scan_on_scavenge_pages_);
     }
   }
 
   inline void decrement_scan_on_scavenge_pages() {
     scan_on_scavenge_pages_--;
     if (FLAG_gc_verbose) {
@@ skipping 1360 matching lines @@
   double OldGenerationMutatorUtilization();
 
   void ReduceNewSpaceSize();
 
   bool TryFinalizeIdleIncrementalMarking(
       double idle_time_in_ms, size_t size_of_objects,
       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,
                              double deadline_in_ms);
 
   void IdleNotificationEpilogue(GCIdleTimeAction action,
                                 GCIdleTimeHandler::HeapState heap_state,
                                 double start_ms, double deadline_in_ms);
   void CheckAndNotifyBackgroundIdleNotification(double idle_time_in_ms,
                                                 double now_ms);
 
@@ skipping 583 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_HEAP_H_