Recognise variable names when parsing CSS property names

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

 // Copyright 2014 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 "core/css/parser/CSSParserImpl.h"
 
 #include "core/css/CSSCustomIdentValue.h"
 #include "core/css/CSSCustomPropertyDeclaration.h"
 #include "core/css/CSSKeyframesRule.h"
 #include "core/css/CSSStyleSheet.h"
@@ skipping 748 matching lines @@
         --last;
         while (last->type() == WhitespaceToken)
             --last;
         if (last->type() == DelimiterToken && last->delimiter() == '!') {
             important = true;
             declarationValueEnd = last;
         }
     }
 
     size_t propertiesCount = m_parsedProperties.size();
-    if (unresolvedProperty == CSSPropertyInvalid && CSSVariableParser::isValidVariableName(token)) {
+    // TODO(timloh): Shouldn't this only be for StyleRule::Style?

[rune, 2016/08/29 07:48:42]

Yes, and it's observable as a bug. Reported 641873. Could you add the issue
number to the TODO?

[Timothy Loh, 2016/08/29 08:15:50]

Done.

+    if (unresolvedProperty == CSSPropertyVariable) {
         AtomicString variableName = token.value().toAtomicString();
         consumeVariableValue(range.makeSubRange(&range.peek(), declarationValueEnd), variableName, important);
     }
 
     if (important && (ruleType == StyleRule::FontFace || ruleType == StyleRule::Keyframe))
         return;
 
-    if (unresolvedProperty != CSSPropertyInvalid) {
+    if (unresolvedProperty != CSSPropertyInvalid && unresolvedProperty != CSSPropertyVariable) {
         if (m_styleSheet && m_styleSheet->singleOwnerDocument())
             Deprecation::warnOnDeprecatedProperties(m_styleSheet->singleOwnerDocument()->frame(), unresolvedProperty);
         consumeDeclarationValue(range.makeSubRange(&range.peek(), declarationValueEnd), unresolvedProperty, important, ruleType);
     }
 
     if (m_observerWrapper && (ruleType == StyleRule::Style || ruleType == StyleRule::Keyframe)) {
         m_observerWrapper->observer().observeProperty(
             m_observerWrapper->startOffset(rangeCopy), m_observerWrapper->endOffset(rangeCopy),
             important, m_parsedProperties.size() != propertiesCount);
     }
@@ skipping 25 matching lines @@
         else
             return nullptr; // Parser error, invalid value in keyframe selector
         if (range.atEnd())
             return result;
         if (range.consume().type() != CommaToken)
             return nullptr; // Parser error
     }
 }
 
 } // namespace blink