[Media Router] Implement an internal Media Routes observer.

chrome/browser/media/router/mojo/media_router.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 media_router.interfaces;
 
 // Represents an output sink to which media can be routed.
 struct MediaSink {
   enum IconType {
     CAST,
@@ skipping 101 matching lines @@
   string? message;
   // Used when the |type| is BINARY.
   array<uint8>? data;
 };
 
 // Maps to a ResultCode value in route_request_result.h
 // The enum defined here is a subset of those defined in route_request_result.h.
 enum RouteRequestResultCode {
   UNKNOWN_ERROR,
   OK,
-  TIMED_OUT
+  TIMED_OUT,
+  ROUTE_NOT_FOUND
 };
 
 // Modeled after the MediaRouter interface defined in
 // chrome/browser/media/router/media_router.h
 interface MediaRouteProvider {
   // Creates a media route from |media_source| to the sink given by |sink_id|.
   //
   // The presentation ID of the route created will be |presentation_id|, but it
   // may be overridden by a provider implementation. The presentation ID will
   // be used by the presentation API to refer to the created route.
@@ skipping 216 matching lines @@
   // changed to |state|.
   OnPresentationConnectionStateChanged(
       string route_id, PresentationConnectionState state);
 
   // Called when the presentation connected to route |route_id| has closed.
   OnPresentationConnectionClosed(
       string route_id, PresentationConnectionCloseReason reason,
       string message);
 };