Move CSSCalcExpressionNode and subclasses to the oilpan heap.

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 a9fafd2334bb425abdd4db6235d33ee00bf99f8a..836cffcd72de9d2d8e271f3fc078bbcc52a069fc 100644
--- a/Source/core/css/CSSCalculationValue.h
+++ b/Source/core/css/CSSCalculationValue.h
@@ -56,7 +56,8 @@ enum CalculationCategory {
     CalcOther
 };
 
-class CSSCalcExpressionNode : public RefCounted<CSSCalcExpressionNode> {
+class CSSCalcExpressionNode : public RefCountedWillBeGarbageCollected<CSSCalcExpressionNode> {
+    DECLARE_GC_INFO;
 public:
     enum Type {
         CssCalcPrimitiveValue = 1,
@@ -76,6 +77,8 @@ public:
     virtual CSSPrimitiveValue::UnitTypes primitiveType() const = 0;
     bool isInteger() const { return m_isInteger; }
 
+    virtual void trace(Visitor*) { }
+
 protected:
     CSSCalcExpressionNode(CalculationCategory category, bool isInteger)
         : m_category(category)
@@ -90,13 +93,13 @@ protected:
 class CSSCalcValue : public CSSValue {
 public:
     static PassRefPtrWillBeRawPtr<CSSCalcValue> create(CSSParserString name, CSSParserValueList*, ValueRange);
-    static PassRefPtrWillBeRawPtr<CSSCalcValue> create(PassRefPtr<CSSCalcExpressionNode>, ValueRange = ValueRangeAll);
+    static PassRefPtrWillBeRawPtr<CSSCalcValue> create(PassRefPtrWillBeRawPtr<CSSCalcExpressionNode>, ValueRange = ValueRangeAll);
     static PassRefPtrWillBeRawPtr<CSSCalcValue> create(const CalculationValue* value, float zoom) { return adoptRefCountedWillBeRefCountedGarbageCollected(new CSSCalcValue(value, zoom)); }
 
-    static PassRefPtr<CSSCalcExpressionNode> createExpressionNode(PassRefPtr<CSSPrimitiveValue>, bool isInteger = false);
-    static PassRefPtr<CSSCalcExpressionNode> createExpressionNode(PassRefPtr<CSSCalcExpressionNode>, PassRefPtr<CSSCalcExpressionNode>, CalcOperator);
-    static PassRefPtr<CSSCalcExpressionNode> createExpressionNode(const CalcExpressionNode*, float zoom);
-    static PassRefPtr<CSSCalcExpressionNode> createExpressionNode(const Length&, float zoom);
+    static PassRefPtrWillBeRawPtr<CSSCalcExpressionNode> createExpressionNode(PassRefPtrWillBeRawPtr<CSSPrimitiveValue>, bool isInteger = false);
+    static PassRefPtrWillBeRawPtr<CSSCalcExpressionNode> createExpressionNode(PassRefPtrWillBeRawPtr<CSSCalcExpressionNode>, PassRefPtrWillBeRawPtr<CSSCalcExpressionNode>, CalcOperator);
+    static PassRefPtrWillBeRawPtr<CSSCalcExpressionNode> createExpressionNode(const CalcExpressionNode*, float zoom);
+    static PassRefPtrWillBeRawPtr<CSSCalcExpressionNode> createExpressionNode(const Length&, float zoom);
 
     PassRefPtr<CalculationValue> toCalcValue(const CSSToLengthConversionData& conversionData) const
     {
@@ -113,10 +116,10 @@ public:
     String customCSSText() const;
     bool equals(const CSSCalcValue&) const;
 
-    void traceAfterDispatch(Visitor* visitor) { CSSValue::traceAfterDispatch(visitor); }
+    void traceAfterDispatch(Visitor*);
 
 private:
-    CSSCalcValue(PassRefPtr<CSSCalcExpressionNode> expression, ValueRange range)
+    CSSCalcValue(PassRefPtrWillBeRawPtr<CSSCalcExpressionNode> expression, ValueRange range)
         : CSSValue(CalculationClass)
         , m_expression(expression)
         , m_nonNegative(range == ValueRangeNonNegative)
@@ -131,7 +134,7 @@ private:
 
     double clampToPermittedRange(double) const;
 
-    const RefPtr<CSSCalcExpressionNode> m_expression;
+    const RefPtrWillBeMember<CSSCalcExpressionNode> m_expression;
     const bool m_nonNegative;
 };