Repeatedly overapproximate the weak closure as long as we make progress

src/heap/incremental-marking.h

 // 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.
 
 #ifndef V8_HEAP_INCREMENTAL_MARKING_H_
 #define V8_HEAP_INCREMENTAL_MARKING_H_
 
 
 #include "src/execution.h"
 #include "src/heap/mark-compact.h"
@@ skipping 23 matching lines @@
     DCHECK(state_ == STOPPED || FLAG_incremental_marking);
     return state_;
   }
 
   bool should_hurry() { return should_hurry_; }
   void set_should_hurry(bool val) { should_hurry_ = val; }
 
   bool weak_closure_was_overapproximated() const {
     return weak_closure_was_overapproximated_;
   }
-  void set_weak_closure_was_overapproximated(bool val) {
-    weak_closure_was_overapproximated_ = val;
-  }
 
   inline bool IsStopped() { return state() == STOPPED; }
 
   INLINE(bool IsMarking()) { return state() >= MARKING; }
 
   inline bool IsMarkingIncomplete() { return state() == MARKING; }
 
   inline bool IsComplete() { return state() == COMPLETE; }
 
   GCRequestType request_type() const { return request_type_; }
@@ skipping 185 matching lines @@
   size_t idle_marking_delay_counter_;
 
   int no_marking_scope_depth_;
 
   int unscanned_bytes_of_large_object_;
 
   bool was_activated_;
 
   bool weak_closure_was_overapproximated_;
 
+  int weak_closure_approximation_rounds_;
+
   GCRequestType request_type_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncrementalMarking);
 };
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_INCREMENTAL_MARKING_H_