mash: Migrate locale observer and notification to common.

ash/system/tray/system_tray_notifier.cc

Index: ash/system/tray/system_tray_notifier.cc
diff --git a/ash/system/tray/system_tray_notifier.cc b/ash/system/tray/system_tray_notifier.cc
index 21129329a4585bddd7986035eb472b347d37ab78..b8e1aa9e3f1555e9eb092e43de67c544d8896dc1 100644
--- a/ash/system/tray/system_tray_notifier.cc
+++ b/ash/system/tray/system_tray_notifier.cc
@@ -20,14 +20,6 @@ void SystemTrayNotifier::RemoveAudioObserver(AudioObserver* observer) {
   audio_observers_.RemoveObserver(observer);
 }
 
-void SystemTrayNotifier::AddLocaleObserver(LocaleObserver* observer) {
-  locale_observers_.AddObserver(observer);
-}
-
-void SystemTrayNotifier::RemoveLocaleObserver(LocaleObserver* observer) {
-  locale_observers_.RemoveObserver(observer);
-}
-
 void SystemTrayNotifier::AddTracingObserver(TracingObserver* observer) {
   tracing_observers_.AddObserver(observer);
 }
@@ -184,17 +176,6 @@ void SystemTrayNotifier::NotifyTracingModeChanged(bool value) {
       OnTracingModeChanged(value));
 }
 
-void SystemTrayNotifier::NotifyLocaleChanged(
-    LocaleObserver::Delegate* delegate,
-    const std::string& cur_locale,
-    const std::string& from_locale,
-    const std::string& to_locale) {
-  FOR_EACH_OBSERVER(
-      LocaleObserver,
-      locale_observers_,
-      OnLocaleChanged(delegate, cur_locale, from_locale, to_locale));
-}
-
 void SystemTrayNotifier::NotifyUserUpdate() {
   FOR_EACH_OBSERVER(UserObserver,
                     user_observers_,