Added support of calc() for SVGLength

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

 /*
  * Copyright (C) 2011, 2012 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 42 matching lines @@
 // in the addSubtractResult matrix.
 enum CalculationCategory {
     CalcNumber = 0,
     CalcLength,
     CalcPercent,
     CalcPercentNumber,
     CalcPercentLength,
     CalcAngle,
     CalcTime,
     CalcFrequency,
+    CalcLengthNumber,

[rwlbuis, 2016/06/27 18:00:01]

Are you sure you need this one? The Number should default to 'px' so it
basically is a Length too AFAICS.

[Shanmuga Pandi, 2016/06/28 05:15:01]

I think it is needed. for eg. calc(10 + 20px). In this 10 is parsed as
CalcNumber and 20px is parsed as CalcLength. So the result category will be
CalcLengthNumber. CalcLengthNumber should be valid only for SVG. So we need to
have unique category to identfiy.

+    CalcPercentLengthNumber,
     CalcOther
 };
 
 class CSSCalcExpressionNode : public GarbageCollected<CSSCalcExpressionNode> {
 public:
     enum Type {
         CssCalcPrimitiveValue = 1,
         CssCalcBinaryOperation
     };
 
@@ skipping 65 matching lines @@
 
     double clampToPermittedRange(double) const;
 
     const Member<CSSCalcExpressionNode> m_expression;
     const bool m_nonNegative;
 };
 
 } // namespace blink
 
 #endif // CSSCalculationValue_h