Fix i18n number formats in tray power displays

ash/system/chromeos/power/battery_notification.cc

 // Copyright 2015 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 "ash/system/chromeos/power/battery_notification.h"
 
 #include "ash/system/chromeos/power/power_status.h"
 #include "ash/system/system_notifier.h"
-#include "base/strings/string_number_conversions.h"
+#include "base/i18n/number_formatting.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "grit/ash_resources.h"
 #include "grit/ash_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/l10n/time_format.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image.h"
 #include "ui/message_center/message_center.h"
 #include "ui/message_center/notification.h"
@@ skipping 22 matching lines @@
 
   return ui::ResourceBundle::GetSharedInstance().GetImageNamed(resource_id);
 }
 
 std::unique_ptr<Notification> CreateNotification(
     TrayPower::NotificationState notification_state) {
   const PowerStatus& status = *PowerStatus::Get();
 
   base::string16 message = l10n_util::GetStringFUTF16(
       IDS_ASH_STATUS_TRAY_BATTERY_PERCENT,
-      base::IntToString16(status.GetRoundedBatteryPercent()));
+      base::FormatNumber(status.GetRoundedBatteryPercent()));
 
   const base::TimeDelta time = status.IsBatteryCharging()
                                    ? status.GetBatteryTimeToFull()
                                    : status.GetBatteryTimeToEmpty();
   base::string16 time_message;
   if (status.IsUsbChargerConnected()) {
     time_message = l10n_util::GetStringUTF16(
         IDS_ASH_STATUS_TRAY_BATTERY_CHARGING_UNRELIABLE);
   } else if (PowerStatus::ShouldDisplayBatteryTime(time) &&
              !status.IsBatteryDischargingOnLinePower()) {
     int hour = 0, min = 0;
     PowerStatus::SplitTimeIntoHoursAndMinutes(time, &hour, &min);
     if (status.IsBatteryCharging()) {
       time_message = l10n_util::GetStringFUTF16(
-          IDS_ASH_STATUS_TRAY_BATTERY_TIME_UNTIL_FULL,
-          base::IntToString16(hour), base::IntToString16(min));
+          IDS_ASH_STATUS_TRAY_BATTERY_TIME_UNTIL_FULL, base::FormatNumber(hour),

[Daniel Erat, 2016/05/03 19:17:33]

just to check, is some combination of hours and minutes a reasonable assumption
to make for internationally-formatting a duration? there's
base/i18n/time_formatting.h, but it doesn't look like it supports durations.

[stevenjb, 2016/05/03 19:49:09]

+1. This seems like something that we ought to have a common helper function
for, maybe using TimeUnitAmount?

[jungshik at Google, 2016/05/10 08:50:44]

 Do we really need to use "2h 3m" instead of '2 hrs and 3 mins'?  If '2 hrs and
3 mins' is ok (for space), 
you can just use ui::TimeFormat::Detailed(FORMAT_DURATION, LENGTH_SHORT, ...). 
They'll take care of localized digits and symbols. 

We can't use MessageFormatter here because there are two numbers that can be
subject to plural rules (see go/plural internally at Google;  nested plurals are
not supported to avoid combinational explosion. ICU supports it, but it's too
much burden to translators to handle all the possible combinations). 


Alternatively, one can use ICU MeasureFormat with UMEASFMT_WIDTH_NARROW. 
http://icu-project.org/apiref/icu4c/measfmt_8h.html#details  
I have to check if it gives 'h' and 'm'. It might use apostrophe and double
quotation mark (or their better-shaped equivalents).  Ok. I confirmed that
CLDR/ICU uses 'h' and 'm' in English locale and equivalents in other locales (I
spot-checked a few). 

  icu::ErrorCode status = U_SUCCESS;
  icu::Measure measures[2] = {
      icu::Measure(Formattable(hours), icu::MeasureUnit::createHour(status),
                   status),
      icu::Measure(Formattable(minutes), icu::MeasureUnit::createMinute(status),
                   status)};
  icu::MeasureFormat measure_format(icu::Locale::getDefault(),
UMEASFMT_WIDTH_NARROW, status);
  icu::UnicodeString formatted;
  icu::FieldPosition ignore(icu::FieldPosition::DONT_CARE);
  measure_format.formatMeasures(&measures, minutes == 0 ? 1 : 2, formatted,
ignore, status);
  base::string16 result(formatted.getBuffer(), formatted.length());

With that, IDS_ASH_STATUS_TRAY_BATTERY_TIME_UNTIL_FULL needs to be changed to
take the formatted time ( 3h 45m). 

ICU may cache measure format internally (I have to check). If not, you may as
well consider caching |measure_format|. 

[Greg Levin, 2016/05/11 19:43:02]

Thanks for the code snippet... HUGE help!  Got it working in
TimeDurationFormat() with both UMEASFMT_WIDTH_NARROW and _NUMERIC (didn't test
_WIDE and _SHORT, but assume those would work too).

Did you look into caching |measure_format|?  Is that something I should add?  Do
you have an example you could point me to?

+          base::FormatNumber(min));
     } else {
       // This is a low battery warning prompting the user in minutes.
       time_message = ui::TimeFormat::Simple(
           ui::TimeFormat::FORMAT_REMAINING, ui::TimeFormat::LENGTH_LONG,
           base::TimeDelta::FromMinutes(hour * 60 + min));
     }
   }
 
   if (!time_message.empty())
     message = message + base::ASCIIToUTF16("\n") + time_message;
@@ skipping 25 matching lines @@
 
 void BatteryNotification::Update(
     TrayPower::NotificationState notification_state) {
   if (message_center_->FindVisibleNotificationById(kBatteryNotificationId)) {
     message_center_->UpdateNotification(kBatteryNotificationId,
                                         CreateNotification(notification_state));
   }
 }
 
 }  // namespace ash