Make sure we do not start incremental marking in idle notification when incremental marking is turn…

src/heap/gc-idle-time-handler.cc

Index: src/heap/gc-idle-time-handler.cc
diff --git a/src/heap/gc-idle-time-handler.cc b/src/heap/gc-idle-time-handler.cc
index 168cc81c0f627f037d401e348f73512fdcc5a86a..ab84a7301bb2d81ca9c50f6f141e125d28e58330 100644
--- a/src/heap/gc-idle-time-handler.cc
+++ b/src/heap/gc-idle-time-handler.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "src/flags.h"
 #include "src/heap/gc-idle-time-handler.h"
 #include "src/heap/gc-tracer.h"
 #include "src/utils.h"
@@ -322,8 +323,9 @@ GCIdleTimeAction GCIdleTimeHandler::Action(double idle_time_in_ms,
     }
   }
 
-  if (heap_state.incremental_marking_stopped &&
-      !heap_state.can_start_incremental_marking && !reduce_memory) {
+  if (!FLAG_incremental_marking ||
+      (heap_state.incremental_marking_stopped &&
+       !heap_state.can_start_incremental_marking && !reduce_memory)) {
     return NothingOrDone();
   }