Remove unused CSSBasicShape::m_referenceBox

Source/core/css/CSSBasicShapes.h

 /*
  * Copyright (C) 2011 Adobe Systems Incorporated. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above
  *    copyright notice, this list of conditions and the following
  *    disclaimer.
@@ skipping 34 matching lines @@
         CSSBasicShapeEllipseType,
         CSSBasicShapePolygonType,
         CSSBasicShapeCircleType,
         CSSBasicShapeInsetType
     };
 
     virtual Type type() const = 0;
     virtual String cssText() const = 0;
     virtual bool equals(const CSSBasicShape&) const = 0;
 
-    CSSPrimitiveValue* referenceBox() const { return m_referenceBox.get(); }
-    void setReferenceBox(PassRefPtrWillBeRawPtr<CSSPrimitiveValue> referenceBox) { m_referenceBox = referenceBox; }
-
     bool isEllipse() const { return type() == CSSBasicShapeEllipseType; }
     bool isPolygon() const { return type() == CSSBasicShapePolygonType; }
     bool isCircle() const { return type() == CSSBasicShapeCircleType; }
     bool isInset() const { return type() == CSSBasicShapeInsetType; }
 
-    DEFINE_INLINE_VIRTUAL_TRACE() { visitor->trace(m_referenceBox); }
+    DEFINE_INLINE_VIRTUAL_TRACE() { }
 
 protected:
     CSSBasicShape() { }
-    RefPtrWillBeMember<CSSPrimitiveValue> m_referenceBox;
 };
 
 class CSSBasicShapeCircle final : public CSSBasicShape {
 public:
     static PassRefPtrWillBeRawPtr<CSSBasicShapeCircle> create() { return adoptRefWillBeNoop(new CSSBasicShapeCircle); }
 
     String cssText() const override;
     bool equals(const CSSBasicShape&) const override;
 
     CSSPrimitiveValue* centerX() const { return m_centerX.get(); }
@@ skipping 150 matching lines @@
 };
 
 DEFINE_TYPE_CASTS(CSSBasicShapeCircle, CSSBasicShape, shape, shape->isCircle(), shape.isCircle());
 DEFINE_TYPE_CASTS(CSSBasicShapeEllipse, CSSBasicShape, shape, shape->isEllipse(), shape.isEllipse());
 DEFINE_TYPE_CASTS(CSSBasicShapePolygon, CSSBasicShape, shape, shape->isPolygon(), shape.isPolygon());
 DEFINE_TYPE_CASTS(CSSBasicShapeInset, CSSBasicShape, shape, shape->isInset(), shape.isInset());
 
 } // namespace blink
 
 #endif // CSSBasicShapes_h