Create a new local context class.

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

+// Copyright 2017 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/CSSParserLocalContext.h"
+
+namespace blink {
+
+CSSParserLocalContext::CSSParserLocalContext() : use_alias_parsing_(false) {}
+
+CSSParserLocalContext::CSSParserLocalContext(bool use_alias_parsing)
+    : use_alias_parsing_(use_alias_parsing) {}
+
+bool CSSParserLocalContext::GetUseAliasParsing() {
+  return use_alias_parsing_;
+}
+
+}  // namespace blink