[heap] Make the current GCCallbackFlags are part of {Heap}.

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 455b01e3f763b2979333363587ac01059c2d3319..404fa5f4bbba1c988cf0871cb69ba4ebec589866 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -133,6 +133,7 @@ Heap::Heap()
       promotion_queue_(this),
       configured_(false),
       current_gc_flags_(Heap::kNoGCFlags),
+      current_gc_callback_flags_(GCCallbackFlags::kNoGCCallbackFlags),
       external_string_table_(this),
       chunks_queued_for_free_(NULL),
       pending_unmap_job_semaphore_(0),
@@ -742,7 +743,7 @@ void Heap::HandleGCRequest() {
   if (incremental_marking()->request_type() ==
       IncrementalMarking::COMPLETE_MARKING) {
     CollectAllGarbage(current_gc_flags(), "GC interrupt",
-                      incremental_marking()->CallbackFlags());
+                      current_gc_callback_flags());
     return;
   }
   DCHECK(FLAG_overapproximate_weak_closure);
@@ -951,7 +952,7 @@ bool Heap::CollectGarbage(GarbageCollector collector, const char* gc_reason,
   // generator needs incremental marking to stay off after it aborted.
   if (!ShouldAbortIncrementalMarking() && incremental_marking()->IsStopped() &&
       incremental_marking()->ShouldActivateEvenWithoutIdleNotification()) {
-    incremental_marking()->Start(kNoGCFlags, kNoGCCallbackFlags, "GC epilogue");
+    StartIncrementalMarking(kNoGCFlags, kNoGCCallbackFlags, "GC epilogue");
   }
 
   return next_gc_likely_to_collect_more;
@@ -982,7 +983,9 @@ void Heap::StartIncrementalMarking(int gc_flags,
                                    const GCCallbackFlags gc_callback_flags,
                                    const char* reason) {
   DCHECK(incremental_marking()->IsStopped());
-  incremental_marking()->Start(gc_flags, gc_callback_flags, reason);
+  set_current_gc_flags(gc_flags);
+  set_current_gc_callback_flags(gc_callback_flags);
+  incremental_marking()->Start(reason);
 }