Use ICU for string pluralization in the extension permission dialog.

ui/base/l10n/l10n_util_plurals.cc

Index: ui/base/l10n/l10n_util_plurals.cc
diff --git a/ui/base/l10n/l10n_util_plurals.cc b/ui/base/l10n/l10n_util_plurals.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0dc008ff06edb5b10355e2b95e57fb32a97ed8ff
--- /dev/null
+++ b/ui/base/l10n/l10n_util_plurals.cc
@@ -0,0 +1,64 @@
+// 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.
+
+#include "ui/base/l10n/l10n_util_plurals.h"
+
+#include "base/memory/scoped_ptr.h"
+#include "ui/base/l10n/l10n_util.h"
+
+namespace l10n_util {
+
+scoped_ptr<icu::PluralRules> BuildPluralRules() {
+  UErrorCode err = U_ZERO_ERROR;
+  scoped_ptr<icu::PluralRules> rules(
+      icu::PluralRules::forLocale(icu::Locale::getDefault(), err));
+  if (U_FAILURE(err)) {
+    err = U_ZERO_ERROR;
+    icu::UnicodeString fallback_rules("one: n is 1", -1, US_INV);
+    rules.reset(icu::PluralRules::createRules(fallback_rules, err));
+    DCHECK(U_SUCCESS(err));
+  }
+  return rules.Pass();
+}
+
+scoped_ptr<icu::PluralFormat> BuildPluralFormat(
+    const std::vector<int>& message_ids) {
+  const icu::UnicodeString kKeywords[] = {
+      UNICODE_STRING_SIMPLE("other"),
+      UNICODE_STRING_SIMPLE("one"),
+      UNICODE_STRING_SIMPLE("zero"),
+      UNICODE_STRING_SIMPLE("two"),
+      UNICODE_STRING_SIMPLE("few"),
+      UNICODE_STRING_SIMPLE("many"),
+  };
+  DCHECK_EQ(message_ids.size(), arraysize(kKeywords));
+  UErrorCode err = U_ZERO_ERROR;
+  scoped_ptr<icu::PluralRules> rules(BuildPluralRules());
+
+  icu::UnicodeString pattern;
+  for (size_t i = 0; i < arraysize(kKeywords); ++i) {
+    int msg_id = message_ids[i];
+    std::string sub_pattern = GetStringUTF8(msg_id);
+    // NA means this keyword is not used in the current locale.
+    // Even if a translator translated for this keyword, we do not
+    // use it unless it's 'other' (i=0) or it's defined in the rules
+    // for the current locale. Special-casing of 'other' will be removed
+    // once ICU's isKeyword is fixed to return true for isKeyword('other').
+    if (sub_pattern.compare("NA") != 0 &&
+        (i == 0 || rules->isKeyword(kKeywords[i]))) {
+      pattern += kKeywords[i];
+      pattern += UNICODE_STRING_SIMPLE("{");
+      pattern += icu::UnicodeString(sub_pattern.c_str(), "UTF-8");
+      pattern += UNICODE_STRING_SIMPLE("}");
+    }
+  }
+  scoped_ptr<icu::PluralFormat> format = scoped_ptr<icu::PluralFormat>(
+      new icu::PluralFormat(*rules, pattern, err));
+  if (!U_SUCCESS(err)) {
+    return scoped_ptr<icu::PluralFormat>();
+  }
+  return format.Pass();
+}
+
+}  // namespace l10n_util