Hook up over approximating the weak closure to the idle time handler

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

Index: src/heap/gc-idle-time-handler.h
diff --git a/src/heap/gc-idle-time-handler.h b/src/heap/gc-idle-time-handler.h
index 4dd190b07c337fa5f6e27e139d9b3aa6d937df64..3d2e304e623b62709053d5a80dc42943667132a2 100644
--- a/src/heap/gc-idle-time-handler.h
+++ b/src/heap/gc-idle-time-handler.h
@@ -135,6 +135,8 @@ class GCIdleTimeHandler {
   // Incremental marking step time.
   static const size_t kIncrementalMarkingStepTimeInMs = 1;
 
+  static const size_t kMinTimeForOverApproximatingWeakClosureInMs;
+
   class HeapState {
    public:
     void Print();
@@ -192,6 +194,8 @@ class GCIdleTimeHandler {
       size_t idle_time_in_ms, size_t size_of_objects,
       size_t final_incremental_mark_compact_speed_in_bytes_per_ms);
 
+  static bool ShouldDoOverApproximateWeakClosure(size_t idle_time_in_ms);
+
   static bool ShouldDoScavenge(
       size_t idle_time_in_ms, size_t new_space_size, size_t used_new_space_size,
       size_t scavenger_speed_in_bytes_per_ms,