CSS: Use count position values with 3 parts

third_party/WebKit/Source/core/css/properties/CSSPropertyAPIOffsetPosition.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/CSSPropertyAPIOffsetPosition.h"
 
 #include "core/css/CSSValuePair.h"
 #include "core/css/parser/CSSParserContext.h"
 #include "core/css/parser/CSSPropertyParserHelpers.h"
 #include "core/frame/UseCounter.h"
 
 namespace blink {
 
 const CSSValue* CSSPropertyAPIOffsetPosition::parseSingleValue(
     CSSParserTokenRange& range,
     const CSSParserContext& context,
     CSSPropertyID) {
   CSSValueID id = range.Peek().Id();
   if (id == CSSValueAuto)
     return CSSPropertyParserHelpers::ConsumeIdent(range);
+  auto syntax = CSSPropertyParserHelpers::PositionSyntax::kRejectThreeValues;
   CSSValue* value = CSSPropertyParserHelpers::ConsumePosition(
-      range, context.Mode(), CSSPropertyParserHelpers::UnitlessQuirk::kForbid);
+      range, context, CSSPropertyParserHelpers::UnitlessQuirk::kForbid, syntax);
 
   // Count when we receive a valid position other than 'auto'.
   if (value && value->IsValuePair())
     context.Count(UseCounter::kCSSOffsetInEffect);
   return value;
 }
 
 }  // namespace blink