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

chrome/test/data/webui/settings/cr_settings_browsertest.js

Index: chrome/test/data/webui/settings/cr_settings_browsertest.js
diff --git a/chrome/test/data/webui/settings/cr_settings_browsertest.js b/chrome/test/data/webui/settings/cr_settings_browsertest.js
index 061d877d4efaa5d1123de7bc76b1c4145c874ce7..c205465b39ff0a2b6ddad58f15faa1b5a4cfd860 100644
--- a/chrome/test/data/webui/settings/cr_settings_browsertest.js
+++ b/chrome/test/data/webui/settings/cr_settings_browsertest.js
@@ -659,3 +659,26 @@ CrSettingsRouteTest.prototype = {
 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();
+});