Add Media Router result code for user cancellation

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.mojom;
 
 import "mojo/common/common_custom_types.mojom";
 
 // Represents an output sink to which media can be routed.
 struct MediaSink {
@@ skipping 109 matching lines @@
   // differently.
   string input;
   // The user's current hosted domain.
   string domain;
 };
 
 // Keep in sync with:
 // - RouteRequestResult::ResultCode in route_request_result.h
 // - MediaRouteProviderResult enum in tools/metrics/histograms.xml.
 // - mr.RouteRequestResultCode in route_request_error.js
+// - RouteRequestResultCodeFromMojo in media_router_type_converters.cc
 enum RouteRequestResultCode {
   UNKNOWN_ERROR,
   OK,
   TIMED_OUT,
   ROUTE_NOT_FOUND,
   SINK_NOT_FOUND,
   INVALID_ORIGIN,
   INCOGNITO_MISMATCH,
-  NO_SUPPORTED_PROVIDER
+  NO_SUPPORTED_PROVIDER,
+  CANCELLED
 // New values must be added here.
 };
 
 // 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
@@ skipping 236 matching lines @@
 
   // Called when the a batch of messages arrives from the media sink for the
   // route given by |route_id|.
   // |StartListeningForRouteMessages| must be called first in order to receive
   // messages.
   // |route_id|: ID of route of the messages.
   // |messages|: A non-empty list of messages received.
   OnRouteMessagesReceived(string route_id,
                           array<RouteMessage> messages);
 };