ash: Use mojo LocaleNotificationController interface.

ash/public/interfaces/locale.mojom

Index: ash/public/interfaces/locale.mojom
diff --git a/ash/public/interfaces/locale.mojom b/ash/public/interfaces/locale.mojom
new file mode 100644
index 0000000000000000000000000000000000000000..c1395fe89c21a2ef74a9dbfb7d44e1c4760bef49
--- /dev/null
+++ b/ash/public/interfaces/locale.mojom
@@ -0,0 +1,16 @@
+// Copyright 2016 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.
+
+module ash.mojom;
+
+enum LocaleNotificationResult {
+  ACCEPT,
+  REVERT
+};
+
+// Used by Chrome to make ash show a notification.
+interface LocaleNotificationController {
+  NotifyLocaleChanged(string current, string from, string to)
+      => (LocaleNotificationResult result);
+};