Make CSSParserContext be garbage collected.

third_party/WebKit/Source/core/css/properties/CSSPropertyAPITranslate.cpp

 // Copyright 2016 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/CSSPropertyAPITranslate.h"
 
 #include "core/css/CSSValueList.h"
 #include "core/css/parser/CSSParserTokenRange.h"
 #include "core/css/parser/CSSPropertyParser.h"
 #include "core/css/parser/CSSPropertyParserHelpers.h"
 
 namespace blink {
 
 const CSSValue* CSSPropertyAPITranslate::parseSingleValue(
     CSSParserTokenRange& range,
-    const CSSParserContext& context) {
+    const CSSParserContext* context) {
   DCHECK(RuntimeEnabledFeatures::cssIndependentTransformPropertiesEnabled());
   CSSValue* translate = CSSPropertyParserHelpers::consumeLengthOrPercent(
-      range, context.mode(), ValueRangeAll);
+      range, context->mode(), ValueRangeAll);
   if (!translate)
     return nullptr;
   CSSValueList* list = CSSValueList::createSpaceSeparated();
   list->append(*translate);
   translate = CSSPropertyParserHelpers::consumeLengthOrPercent(
-      range, context.mode(), ValueRangeAll);
+      range, context->mode(), ValueRangeAll);
   if (translate) {
     list->append(*translate);
-    translate = CSSPropertyParserHelpers::consumeLength(range, context.mode(),
+    translate = CSSPropertyParserHelpers::consumeLength(range, context->mode(),
                                                         ValueRangeAll);
     if (translate)
       list->append(*translate);
   }
 
   return list;
 }
 
 }  // namespace blink