[CSS Typed OM] Implement support for CSSValue -> CSSCalcLength

third_party/WebKit/Source/core/css/CSSCalculationValue.h

Index: third_party/WebKit/Source/core/css/CSSCalculationValue.h
diff --git a/third_party/WebKit/Source/core/css/CSSCalculationValue.h b/third_party/WebKit/Source/core/css/CSSCalculationValue.h
index 9fccae64a9b231343571d9bfa38b8e4c33b0342c..086aba2d09e91c446b5de3508da89a25de1b2adf 100644
--- a/third_party/WebKit/Source/core/css/CSSCalculationValue.h
+++ b/third_party/WebKit/Source/core/css/CSSCalculationValue.h
@@ -82,6 +82,9 @@ class CSSCalcExpressionNode : public GarbageCollected<CSSCalcExpressionNode> {
     return m_category == other.m_category && m_isInteger == other.m_isInteger;
   }
   virtual Type getType() const = 0;
+  virtual const CSSCalcExpressionNode* leftExpressionNode() const = 0;
+  virtual const CSSCalcExpressionNode* rightExpressionNode() const = 0;
+  virtual CalcOperator operatorType() const = 0;
 
   CalculationCategory category() const { return m_category; }
   virtual CSSPrimitiveValue::UnitType typeWithCalcResolved() const = 0;