Reapply r168568 "Remove unneeded destructors and add finalization support to various classes."

Source/core/css/CSSCalculationValue.h

Index: Source/core/css/CSSCalculationValue.h
diff --git a/Source/core/css/CSSCalculationValue.h b/Source/core/css/CSSCalculationValue.h
index ca4c5bfd24818561f43f06a899103a523a8bfd8d..a375e7d58f0e8d8c83c3b3d7fc40d3b7f65708a5 100644
--- a/Source/core/css/CSSCalculationValue.h
+++ b/Source/core/css/CSSCalculationValue.h
@@ -56,14 +56,14 @@ enum CalculationCategory {
     CalcOther
 };
 
-class CSSCalcExpressionNode : public RefCountedWillBeGarbageCollected<CSSCalcExpressionNode> {
+class CSSCalcExpressionNode : public RefCountedWillBeGarbageCollectedFinalized<CSSCalcExpressionNode> {
 public:
     enum Type {
         CssCalcPrimitiveValue = 1,
         CssCalcBinaryOperation
     };
 
-    virtual ~CSSCalcExpressionNode() = 0;
+    virtual ~CSSCalcExpressionNode() { }
     virtual bool isZero() const = 0;
     virtual PassOwnPtr<CalcExpressionNode> toCalcValue(const CSSToLengthConversionData&) const = 0;
     virtual double doubleValue() const = 0;