[Media Router] Assign each route a current cast mode if possible

chrome/browser/resources/media_router/media_router_data.js

 // 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.
 
 // Any strings used here will already be localized. Values such as
 // CastMode.type or IDs will be defined elsewhere and determined later.
 
 cr.exportPath('media_router');
 
 /**
@@ skipping 180 matching lines @@
 
     /** @type {?number} */
     this.tabId = tabId;
 
     /** @type {boolean} */
     this.isLocal = isLocal;
 
     /** @type {boolean} */
     this.canJoin = canJoin;
 
+    /** @type {number|undefined} */
+    this.currentCastMode = undefined;
+
     /** @type {?string} */
     this.customControllerPath = customControllerPath;
   };
 
 
   /**
    * @param {string} id The ID of the media sink.
    * @param {string} name The name of the sink.
    * @param {?string} description Optional description of the sink.
    * @param {?string} domain Optional domain of the sink.
@@ skipping 47 matching lines @@
 
   return {
     AUTO_CAST_MODE: AUTO_CAST_MODE,
     CastMode: CastMode,
     Issue: Issue,
     Route: Route,
     Sink: Sink,
     TabInfo: TabInfo,
   };
 });