[Variables] Enable get/setProperty and similar APIs from the CSSOM

third_party/WebKit/Source/core/css/parser/CSSVariableParser.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/css/parser/CSSVariableParser.h"
 
 #include "core/css/CSSCustomPropertyDeclaration.h"
 #include "core/css/parser/CSSParserTokenRange.h"
 #include "core/css/parser/CSSParserValues.h"
 
 namespace blink {
 
 bool CSSVariableParser::isValidVariableName(const CSSParserToken& token)
 {
     if (token.type() != IdentToken)
         return false;
 
     CSSParserString value = token.value();
     return value.length() >= 2 && value[0] == '-' && value[1] == '-';
 }
 
+bool CSSVariableParser::isValidVariableName(const String& string)
+{
+    return string.length() >= 2 && string[0] == '-' && string[1] == '-';
+}
+
 bool isValidVariableReference(CSSParserTokenRange);
 
 bool classifyBlock(CSSParserTokenRange range, bool& hasReferences, bool isTopLevelBlock = true)
 {
     while (!range.atEnd()) {
         if (range.peek().blockType() == CSSParserToken::BlockStart) {
             const CSSParserToken& token = range.peek();
             CSSParserTokenRange block = range.consumeBlock();
             if (token.functionId() == CSSValueVar) {
                 if (!isValidVariableReference(block))
@@ skipping 81 matching lines @@
     CSSValueID type = classifyVariableRange(range, hasReferences);
 
     if (type == CSSValueInvalid)
         return nullptr;
     if (type == CSSValueInternalVariableValue)
         return CSSCustomPropertyDeclaration::create(variableName, CSSVariableData::create(range, hasReferences));
     return CSSCustomPropertyDeclaration::create(variableName, type);
 }
 
 } // namespace blink