Settings Router Refactor: Improve chrome://md-settings/foobar behavior.

chrome/test/data/webui/settings/cr_settings_browsertest.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.
 
 /** @fileoverview Runs the Polymer Settings tests. */
 
 /** @const {string} Path to source root. */
 var ROOT_PATH = '../../../../../';
 
 // Polymer BrowserTest fixture.
@@ skipping 641 matching lines @@
   browsePreload: 'chrome://md-settings/route.html',
 
   extraLibraries: CrSettingsBrowserTest.prototype.extraLibraries.concat([
     'route_tests.js',
   ]),
 };
 
 TEST_F('CrSettingsRouteTest', 'All', function() {
   mocha.run();
 });
+
+/**
+ * @constructor
+ * @extends {SettingsPageBrowserTest}
+*/
+function CrSettingsNonExistentRouteTest() {}
+
+CrSettingsNonExistentRouteTest.prototype = {
+  __proto__: CrSettingsBrowserTest.prototype,
+
+  /** @override */
+  browsePreload: 'chrome://md-settings/non/existent/route',
+};
+
+TEST_F('CrSettingsNonExistentRouteTest', 'All', function() {
+  suite('NonExistentRoutes', function() {
+    test('redirect to basic', function() {
+      assertEquals(settings.Route.BASIC, settings.getCurrentRoute());
+      assertEquals('/', location.pathname);
+    });
+  });
+  mocha.run();
+});