Use ICU for string pluralization in the extension permission dialog.

ui/base/l10n/l10n_util_internal.h

Index: ui/base/l10n/l10n_util_internal.h
diff --git a/ui/base/l10n/l10n_util_internal.h b/ui/base/l10n/l10n_util_internal.h
new file mode 100644
index 0000000000000000000000000000000000000000..ce310549dce1e4cbb572bb69b5c7fbecb164a71e
--- /dev/null
+++ b/ui/base/l10n/l10n_util_internal.h
@@ -0,0 +1,29 @@
+// 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 localized content that
+// expose ICU types in their interface.

[tony, 2013/09/20 16:56:44]

Nit: I have a slight preference for a file name like l10n_util_plurals.h over
internal, which doesn't really say what's in the file.  FWIW, we expose ICU in
l10n_util_collator.h already.  Alternately, in a follow up change, we could move
the non-exported icu functions in l10n_util_collator.h into
l10n_util_internal.h.

[Sam McNally, 2013/09/22 22:53:03]

Done.

+
+#ifndef UI_BASE_L10N_L10N_UTIL_INTERNAL_H_
+#define UI_BASE_L10N_L10N_UTIL_INTERNAL_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/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(std::vector<int> message_ids);

[tony, 2013/09/20 16:56:44]

|message_ids| should be a const ref.

[Sam McNally, 2013/09/22 22:53:03]

Done.

+
+}  // namespace l10n_util
+
+#endif  // UI_BASE_L10N_L10N_UTIL_INTERNAL_H_