Support nested calc()

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

 /*
  * 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 618 matching lines @@
             CSSPrimitiveValue::create(token.numericValue(), type), token.numericValueType() == IntegerValueType);
 
         return true;
     }
 
     bool parseValueTerm(CSSParserTokenRange& tokens, int depth, Value* result)
     {
         if (checkDepthAndIndex(&depth, tokens) != OK)
             return false;
 
-        if (tokens.peek().type() == LeftParenthesisToken) {
+        if (tokens.peek().type() == LeftParenthesisToken || tokens.peek().functionId() == CSSValueCalc) {
             CSSParserTokenRange innerRange = tokens.consumeBlock();
             tokens.consumeWhitespace();
             innerRange.consumeWhitespace();
             return parseValueExpression(innerRange, depth, result);
         }
 
         return parseValue(tokens, result);
     }
 
     bool parseValueMultiplicativeExpression(CSSParserTokenRange& tokens, int depth, Value* result)
@@ skipping 84 matching lines @@
 
     return expression ? new CSSCalcValue(expression, range) : nullptr;
 }
 
 RawPtr<CSSCalcValue> CSSCalcValue::create(RawPtr<CSSCalcExpressionNode> expression, ValueRange range)
 {
     return new CSSCalcValue(expression, range);
 }
 
 } // namespace blink