Revert of Changed CSSParserContext argument from * to & for null safety.

third_party/WebKit/Source/core/css/properties/CSSPropertyAPIFontVariantNumeric.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/properties/CSSPropertyAPIFontVariantNumeric.h"
 
 #include "core/css/parser/CSSPropertyParserHelpers.h"
 #include "core/css/parser/FontVariantNumericParser.h"
 
 namespace blink {
 
 const CSSValue* CSSPropertyAPIFontVariantNumeric::parseSingleValue(
     CSSParserTokenRange& range,
-    const CSSParserContext& context) {
+    const CSSParserContext* context) {
   if (range.peek().id() == CSSValueNormal)
     return CSSPropertyParserHelpers::consumeIdent(range);
 
   FontVariantNumericParser numericParser;
   do {
     if (numericParser.consumeNumeric(range) !=
         FontVariantNumericParser::ParseResult::ConsumedValue)
       return nullptr;
   } while (!range.atEnd());
 
   return numericParser.finalizeValue();
 }
 
 }  // namespace blink