Merge VisitorScope to Visitor

third_party/WebKit/Source/platform/heap/Visitor.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 299 matching lines @@
         // GCing thread. This is used for GCType=ThreadTerminationGC.
         ThreadLocalMarking,
         // This visitor just marks objects and ignores weak processing.
         // This is used for GCType=TakeSnapshot.
         SnapshotMarking,
         // This visitor is used to trace objects during weak processing.
         // This visitor is allowed to trace only already marked objects.
         WeakProcessing,
     };
 
-    virtual ~Visitor() { }
+    static PassOwnPtr<Visitor> create(ThreadState*, BlinkGC::GCType);
+
+    virtual ~Visitor();
 
     using VisitorHelper<Visitor>::mark;
 
     // This method marks an object and adds it to the set of objects
     // that should have their trace method called. Since not all
     // objects have vtables we have to have the callback as an
     // explicit argument, but we can use the templated one-argument
     // mark method above to automatically provide the callback
     // function.
     virtual void mark(const void*, TraceCallback) = 0;
@@ skipping 36 matching lines @@
     virtual void registerWeakTable(const void*, EphemeronCallback, EphemeronCallback) = 0;
 #if ENABLE(ASSERT)
     virtual bool weakTableRegistered(const void*) = 0;
 #endif
 
     virtual bool ensureMarked(const void*) = 0;
 
     inline MarkingMode markingMode() const { return m_markingMode; }
 
 protected:
-    explicit Visitor(MarkingMode markingMode)
-        : m_markingMode(markingMode)
-    { }
+    Visitor(ThreadState*, MarkingMode);
 
     virtual void registerWeakCellWithCallback(void**, WeakCallback) = 0;
 
 private:
     static Visitor* fromHelper(VisitorHelper<Visitor>* helper) { return static_cast<Visitor*>(helper); }
 
+    ThreadState* m_state;
     const MarkingMode m_markingMode;
     bool m_isGlobalMarkingVisitor;
 };
 
-class VisitorScope final {
-    STACK_ALLOCATED();
-public:
-    VisitorScope(ThreadState*, BlinkGC::GCType);
-    ~VisitorScope();
-    Visitor* visitor() const { return m_visitor.get(); }
-
-private:
-    ThreadState* m_state;
-    OwnPtr<Visitor> m_visitor;
-};
-
 } // namespace blink
 
 #endif // Visitor_h