[heap] Fix finalization of incremental marking race.

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/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/scopeinfo.h"
 #include "src/base/bits.h"
@@ skipping 746 matching lines @@
 
 
 void Heap::HandleGCRequest() {
   if (incremental_marking()->request_type() ==
       IncrementalMarking::COMPLETE_MARKING) {
     CollectAllGarbage(current_gc_flags_, "GC interrupt",
                       current_gc_callback_flags_);
     return;
   }
   DCHECK(FLAG_finalize_marking_incrementally);
-  if (!incremental_marking()->finalize_marking_completed()) {
+  if (incremental_marking()->IsMarking() &&
+      !incremental_marking()->finalize_marking_completed()) {
     FinalizeIncrementalMarking("GC interrupt: finalize incremental marking");
   }
 }
 
 
 void Heap::ScheduleIdleScavengeIfNeeded(int bytes_allocated) {
   scavenge_job_->ScheduleIdleTaskIfNeeded(this, bytes_allocated);
 }
 
 
@@ skipping 5321 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8