mash: Migrate locale observer and notification to common.

ash/system/locale/locale_observer.h

Index: ash/system/locale/locale_observer.h
diff --git a/ash/system/locale/locale_observer.h b/ash/system/locale/locale_observer.h
deleted file mode 100644
index 939bd60faa979e018b7736ad9e82fe68191de278..0000000000000000000000000000000000000000
--- a/ash/system/locale/locale_observer.h
+++ /dev/null
@@ -1,32 +0,0 @@
-// Copyright (c) 2012 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.
-
-#ifndef ASH_SYSTEM_LOCALE_LOCALE_OBSERVER_H_
-#define ASH_SYSTEM_LOCALE_LOCALE_OBSERVER_H_
-
-#include "ash/ash_export.h"
-
-namespace ash {
-
-class ASH_EXPORT LocaleObserver {
- public:
-  class Delegate {
-   public:
-    virtual ~Delegate() {}
-
-    virtual void AcceptLocaleChange() = 0;
-    virtual void RevertLocaleChange() = 0;
-  };
-
-  virtual ~LocaleObserver() {}
-
-  virtual void OnLocaleChanged(Delegate* delegate,
-                               const std::string& cur_locale,
-                               const std::string& from_locale,
-                               const std::string& to_locale) = 0;
-};
-
-}  // namespace ash
-
-#endif  // ASH_SYSTEM_LOCALE_LOCALE_OBSERVER_H_