Add module suffix in .mojom files for components/arc

components/arc/common/notifications.mojom

 // 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.
 
-module arc;
+module arc.mojom;
 
 // These values must be matched with the NOTIFICATION_EVENT_* constants in
 // com.android.server.ArcNotificationListenerService.
 enum ArcNotificationEvent {
   BODY_CLICKED = 0,
   CLOSED = 1,
   // Five buttons at maximum (message_center::kNotificationMaximumItems = 5).
   BUTTON_1_CLICKED = 2,
   BUTTON_2_CLICKED = 3,
   BUTTON_3_CLICKED = 4,
@@ skipping 78 matching lines @@
 
 // TODO(lhchavez): Migrate all request/response messages to Mojo.
 interface NotificationsInstance {
   // Establishes full-duplex communication with the host.
   Init(NotificationsHost host_ptr);
 
   // Sends an event from Chrome notification UI to Android.
   // |event| is a type of occured event.
   SendNotificationEventToAndroid(string key, ArcNotificationEvent event);
 };