[Media Router WebUI] Handle route details in incognito.

chrome/browser/resources/media_router/elements/route_details/route_details.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.
 
 // This Polymer element shows information from media that is currently cast
 // to a device.
 Polymer({
   is: 'route-details',
 
   properties: {
     /**
      * The text for the current casting activity status.
      * @private {string}
      */
     activityStatus_: {
       type: String,
       value: '',
     },
 
     /**
+     * Whether the browser is currently incognito.
+     * @type {boolean}
+     */
+    isOffTheRecord: {
+      type: Boolean,
+      value: false,
+    },
+
+    /**
      * The route to show.
      * @type {?media_router.Route}
      */
     route: {
       type: Object,
       value: null,
       observer: 'maybeLoadCustomController_',
     },
 
     /**
@@ skipping 54 matching lines @@
    * Updates |activityStatus_| for the default view.
    *
    * @private
    */
   maybeLoadCustomController_: function() {
     this.activityStatus_ = this.route ?
         loadTimeData.getStringF('castingActivityStatus',
                                 this.route.description) :
         '';
 
-    if (!this.route || !this.route.customControllerPath) {
+    if (!this.route || !this.route.customControllerPath ||
+        this.isOffTheRecord) {
       this.isCustomControllerHidden_ = true;
       return;
     }
 
     // Show custom controller
     var extensionview = this.$['custom-controller'];
 
     // Do nothing if the url is the same and the view is not hidden.
     if (this.route.customControllerPath == extensionview.src &&
         !this.isCustomControllerHidden_)
       return;
 
     var that = this;
     extensionview.load(this.route.customControllerPath)
     .then(function() {
       // Load was successful; show the custom controller.
       that.isCustomControllerHidden_ = false;
     }, function() {
       // Load was unsuccessful; fall back to default view.
       that.isCustomControllerHidden_ = true;
     });
   },
 });