Update from https://crrev.com/327068

base/i18n/string_compare.cc

 // Copyright (c) 2013 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 "base/i18n/string_compare.h"
 
 #include "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
 
 namespace base {
 namespace i18n {
 
 // Compares the character data stored in two different string16 strings by
 // specified Collator instance.
-UCollationResult CompareString16WithCollator(const icu::Collator* collator,
+UCollationResult CompareString16WithCollator(const icu::Collator& collator,
                                              const string16& lhs,
                                              const string16& rhs) {
-  DCHECK(collator);
   UErrorCode error = U_ZERO_ERROR;
-  UCollationResult result = collator->compare(
+  UCollationResult result = collator.compare(
       static_cast<const UChar*>(lhs.c_str()), static_cast<int>(lhs.length()),
       static_cast<const UChar*>(rhs.c_str()), static_cast<int>(rhs.length()),
       error);
   DCHECK(U_SUCCESS(error));
   return result;
 }
 
 }  // namespace i18n
 }  // namespace base