Add TrayLocale for locale change notifications.

chrome/browser/chromeos/locale_change_guard.h

Index: chrome/browser/chromeos/locale_change_guard.h
diff --git a/chrome/browser/chromeos/locale_change_guard.h b/chrome/browser/chromeos/locale_change_guard.h
index 2c9ac6e5fd8beff1d67772b21225ab033f842f05..b5024630e5f6efef690a5227d29625cb514fc1b9 100644
--- a/chrome/browser/chromeos/locale_change_guard.h
+++ b/chrome/browser/chromeos/locale_change_guard.h
@@ -8,6 +8,7 @@
 
 #include <string>
 
+#include "ash/system/locale/locale_observer.h"
 #include "base/compiler_specific.h"
 #include "base/lazy_instance.h"
 #include "base/memory/scoped_ptr.h"
@@ -29,11 +30,16 @@ namespace chromeos {
 // (based on synchronized user preference).  If so: shows notification that
 // allows user to revert change.
 class LocaleChangeGuard : public content::NotificationObserver,
+                          public ash::LocaleObserver::Delegate,
                           public base::SupportsWeakPtr<LocaleChangeGuard> {
  public:
   explicit LocaleChangeGuard(Profile* profile);
   virtual ~LocaleChangeGuard();
 
+  // ash::LocaleChangeDelegate implementation.
+  virtual void AcceptLocaleChange() OVERRIDE;
+  virtual void RevertLocaleChange() OVERRIDE;
+
   // Called just before changing locale.
   void PrepareChangingLocale(
       const std::string& from_locale, const std::string& to_locale);
@@ -44,8 +50,7 @@ class LocaleChangeGuard : public content::NotificationObserver,
  private:
   class Delegate;
 
-  void RevertLocaleChange(const base::ListValue* list);
-  void AcceptLocaleChange();
+  void RevertLocaleChangeCallback(const base::ListValue* list);
   void Check();
 
   // content::NotificationObserver implementation.