Use the ICU syntax message for plural formatting

ui/base/l10n/l10n_util_plurals.h

 // Copyright 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.
 
 // This file contains utility functions for dealing with pluralization of
 // localized content.
 
 #ifndef UI_BASE_L10N_L10N_UTIL_PLURALS_H_
 #define UI_BASE_L10N_L10N_UTIL_PLURALS_H_
 
 #include <string>
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
-#include "third_party/icu/source/i18n/unicode/plurfmt.h"
+#include "third_party/icu/source/i18n/unicode/msgfmt.h"
 #include "third_party/icu/source/i18n/unicode/plurrule.h"
 
 namespace l10n_util {
 
 // Returns a PluralRules for the current locale.
 scoped_ptr<icu::PluralRules> BuildPluralRules();
 
-// Returns a PluralFormat from |message_ids|.  |message_ids| must be size 6 and
-// in order: default, singular, zero, two, few, many.
-scoped_ptr<icu::PluralFormat> BuildPluralFormat(
-    const std::vector<int>& message_ids);
+// Formats |number| using MessageFormat |format| and appends the result
+// to |append_to|.
+// |format| has to be generated with ICU's plural message format.
+// See http://userguide.icu-project.org/formatparse/messages
+void FormatNumberInPlural(const icu::MessageFormat& format, int number,
+                          icu::UnicodeString* append_to, UErrorCode* err);
 
 }  // namespace l10n_util
 
 #endif  // UI_BASE_L10N_L10N_UTIL_PLURALS_H_