GC: Refactor public incremental marking interface in heap

src/heap/incremental-marking.cc

Index: src/heap/incremental-marking.cc
diff --git a/src/heap/incremental-marking.cc b/src/heap/incremental-marking.cc
index 947c961af8993d6efc959d4d1c7765a1c2e352a1..b0d0b31c44a492ac52a737359b570eaec83981b9 100644
--- a/src/heap/incremental-marking.cc
+++ b/src/heap/incremental-marking.cc
@@ -470,7 +470,8 @@ static void PatchIncrementalMarkingRecordWriteStubs(
 }
 
 
-void IncrementalMarking::Start(int mark_compact_flags) {
+void IncrementalMarking::Start(int mark_compact_flags,
+                               const GCCallbackFlags gc_callback_flags) {
   if (FLAG_trace_incremental_marking) {
     PrintF("[IncrementalMarking] Start\n");
   }
@@ -482,6 +483,7 @@ void IncrementalMarking::Start(int mark_compact_flags) {
 
   ResetStepCounters();
 
+  gc_callback_flags_ = gc_callback_flags;
   was_activated_ = true;
 
   if (!heap_->mark_compact_collector()->sweeping_in_progress()) {