Explicitly track whether incremental marking was activated

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 30 matching lines @@
   INLINE(bool IsMarking()) { return state() >= MARKING; }
 
   inline bool IsMarkingIncomplete() { return state() == MARKING; }
 
   inline bool IsComplete() { return state() == COMPLETE; }
 
   bool WorthActivating();
 
   bool ShouldActivate();
 
+  bool WasActivated();
+
   enum CompactionFlag { ALLOW_COMPACTION, PREVENT_COMPACTION };
 
   void Start(CompactionFlag flag = ALLOW_COMPACTION);
 
   void Stop();
 
   void PrepareForScavenge();
 
   void UpdateMarkingDequeAfterScavenge();
 
   void Hurry();
 
   void Finalize();
 
   void Abort();
 
   void MarkingComplete(CompletionAction action);
 
+  void Epilogue();
+
   // It's hard to know how much work the incremental marker should do to make
   // progress in the face of the mutator creating new work for it.  We start
   // of at a moderate rate of work and gradually increase the speed of the
   // incremental marker until it completes.
   // Do some marking every time this much memory has been allocated or that many
   // heavy (color-checking) write barriers have been invoked.
   static const intptr_t kAllocatedThreshold = 65536;
   static const intptr_t kWriteBarriersInvokedThreshold = 32768;
   // Start off by marking this many times more memory than has been allocated.
   static const intptr_t kInitialMarkingSpeed = 1;
@@ skipping 136 matching lines @@
   int marking_speed_;
   intptr_t bytes_scanned_;
   intptr_t allocated_;
   intptr_t write_barriers_invoked_since_last_step_;
   size_t idle_marking_delay_counter_;
 
   int no_marking_scope_depth_;
 
   int unscanned_bytes_of_large_object_;
 
+  bool was_activated_;
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncrementalMarking);
 };
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_INCREMENTAL_MARKING_H_