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

src/heap/heap.cc

 // 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.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 4566 matching lines @@
   if (uncommit) {
     new_space_.Shrink();
     UncommitFromSpace();
   }
 }
 
 
 bool Heap::TryFinalizeIdleIncrementalMarking(
     double idle_time_in_ms, size_t size_of_objects,
     size_t final_incremental_mark_compact_speed_in_bytes_per_ms) {
-  if (incremental_marking()->IsComplete() ||
-      (mark_compact_collector_.marking_deque()->IsEmpty() &&
-       gc_idle_time_handler_.ShouldDoFinalIncrementalMarkCompact(
-           static_cast<size_t>(idle_time_in_ms), size_of_objects,
-           final_incremental_mark_compact_speed_in_bytes_per_ms))) {
+  if (incremental_marking()->IsReadyToOverApproximateWeakClosure() ||
+      (FLAG_overapproximate_weak_closure &&
+       mark_compact_collector_.marking_deque()->IsEmpty() &&
+       gc_idle_time_handler_.ShouldDoOverApproximateWeakClosure(
+           static_cast<size_t>(idle_time_in_ms)))) {
+    OverApproximateWeakClosure(
+        "Idle notification: overapproximate weak closure");
+    return true;
+  } else if (incremental_marking()->IsComplete() ||
+             (mark_compact_collector_.marking_deque()->IsEmpty() &&
+              gc_idle_time_handler_.ShouldDoFinalIncrementalMarkCompact(
+                  static_cast<size_t>(idle_time_in_ms), size_of_objects,
+                  final_incremental_mark_compact_speed_in_bytes_per_ms))) {
     CollectAllGarbage(kNoGCFlags, "idle notification: finalize incremental");
     return true;
   }
   return false;
 }
 
 
 bool Heap::WorthActivatingIncrementalMarking() {
   return incremental_marking()->IsStopped() &&
          incremental_marking()->WorthActivating() && NextGCIsLikelyToBeFull();
@@ skipping 1976 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 }
 }  // namespace v8::internal