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

third_party/WebKit/Source/core/css/properties/CSSPropertyAPIWebkitTextEmphasisStyle.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/CSSPropertyAPIWebkitTextEmphasisStyle.h"
 
 #include "core/css/CSSStringValue.h"
 #include "core/css/CSSValueList.h"
 #include "core/css/parser/CSSPropertyParserHelpers.h"
 
 namespace blink {
 
 const CSSValue* CSSPropertyAPIWebkitTextEmphasisStyle::parseSingleValue(
     CSSParserTokenRange& range,
-    const CSSParserContext& context) {
+    const CSSParserContext* context) {
   CSSValueID id = range.peek().id();
   if (id == CSSValueNone)
     return CSSPropertyParserHelpers::consumeIdent(range);
 
   if (CSSValue* textEmphasisStyle =
           CSSPropertyParserHelpers::consumeString(range))
     return textEmphasisStyle;
 
   CSSIdentifierValue* fill =
       CSSPropertyParserHelpers::consumeIdent<CSSValueFilled, CSSValueOpen>(
@@ skipping 14 matching lines @@
     return parsedValues;
   }
   if (fill)
     return fill;
   if (shape)
     return shape;
   return nullptr;
 }
 
 }  // namespace blink