Use ICU for string pluralization in the extension permission dialog.

chrome/browser/extensions/extension_install_prompt.cc

Index: chrome/browser/extensions/extension_install_prompt.cc
diff --git a/chrome/browser/extensions/extension_install_prompt.cc b/chrome/browser/extensions/extension_install_prompt.cc
index c45fefabf761db8667aba4a5a9730bac109fdc1e..dee12c4df0408364ec7ec0f4ac72ae1b28836d11 100644
--- a/chrome/browser/extensions/extension_install_prompt.cc
+++ b/chrome/browser/extensions/extension_install_prompt.cc
@@ -40,6 +40,8 @@
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
+#include "third_party/icu/source/i18n/unicode/plurfmt.h"
+#include "third_party/icu/source/i18n/unicode/plurrule.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image.h"
@@ -347,9 +349,67 @@ string16 ExtensionInstallPrompt::Prompt::GetOAuthHeading() const {
 }
 
 string16 ExtensionInstallPrompt::Prompt::GetRetainedFilesHeading() const {
-  return l10n_util::GetStringFUTF16(
-      IDS_EXTENSION_PROMPT_RETAINED_FILES,
-      base::IntToString16(GetRetainedFileCount()));
+  const icu::UnicodeString kKeywords[] = {

[tony, 2013/09/19 17:00:40]

This is basically copied from TimeFormatter::BuildFormats().  Please move this
into a helper function in ui/base/l10n/.  Maybe in l10n_util?

[Sam McNally, 2013/09/20 04:10:55]

Done.

+      UNICODE_STRING_SIMPLE("other"),
+      UNICODE_STRING_SIMPLE("one"),
+      UNICODE_STRING_SIMPLE("zero"),
+      UNICODE_STRING_SIMPLE("two"),
+      UNICODE_STRING_SIMPLE("few"),
+      UNICODE_STRING_SIMPLE("many"),
+  };
+  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));
+  }
+
+  const int kRetainedFilesMessageIDs[6] = {
+      IDS_EXTENSION_PROMPT_RETAINED_FILES_DEFAULT,
+      IDS_EXTENSION_PROMPT_RETAINED_FILE_SINGULAR,
+      IDS_EXTENSION_PROMPT_RETAINED_FILES_ZERO,
+      IDS_EXTENSION_PROMPT_RETAINED_FILES_TWO,
+      IDS_EXTENSION_PROMPT_RETAINED_FILES_FEW,
+      IDS_EXTENSION_PROMPT_RETAINED_FILES_MANY,
+  };
+
+  icu::UnicodeString pattern;
+  for (size_t i = 0; i < arraysize(kKeywords); ++i) {
+    int msg_id = kRetainedFilesMessageIDs[i];
+    std::string sub_pattern = l10n_util::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("}");
+    }
+  }
+  icu::PluralFormat format(*rules, pattern, err);
+  if (!U_SUCCESS(err)) {
+    return l10n_util::GetStringFUTF16(
+        IDS_EXTENSION_PROMPT_RETAINED_FILES_FALLBACK,
+        UTF8ToUTF16(base::IntToString(GetRetainedFileCount())));
+  }
+
+  icu::UnicodeString retained_files_string =
+      format.format(static_cast<int>(GetRetainedFileCount()), err);
+  DCHECK(U_SUCCESS(err));
+  int capacity = retained_files_string.length() + 1;
+  DCHECK_GT(capacity, 1);
+  string16 result;
+  retained_files_string.extract(
+      static_cast<UChar*>(WriteInto(&result, capacity)), capacity, err);
+  DCHECK(U_SUCCESS(err));
+  return result;
 }
 
 bool ExtensionInstallPrompt::Prompt::ShouldShowPermissions() const {