MD Settings: Focus cookies search field when exiting cookie details subpage.

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

 // Copyright 2017 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.
 
 suite('settings-animated-pages', function() {
   test('focuses subpage trigger when exiting subpage', function(done) {
     document.body.innerHTML = `
-      <settings-animated-pages section="test-section">
+      <settings-animated-pages
+          section="${settings.Route.SEARCH_ENGINES.section}">
         <neon-animatable route-path="default">
           <button id="subpage-trigger"></button>
         </neon-animatable>
         <neon-animatable route-path="${settings.Route.SEARCH_ENGINES.path}">
           <button id="subpage-trigger"></button>
         </neon-animatable>
       </settings-animated-pages>`;
 
     var animatedPages = document.body.querySelector('settings-animated-pages');
     animatedPages.focusConfig = new Map();
     animatedPages.focusConfig.set(
         settings.Route.SEARCH_ENGINES.path, '#subpage-trigger');
 
-    animatedPages.$.animatedPages.selected = settings.Route.SEARCH_ENGINES.path;
-
     var trigger = document.body.querySelector('#subpage-trigger');
     assertTrue(!!trigger);
     trigger.addEventListener('focus', function() { done(); });
 
-    // Trigger subpage exit.
-    animatedPages.currentRouteChanged(
-        settings.Route.BASIC, settings.Route.SEARCH_ENGINES);
+    // Trigger subpage exit navigation.
+    settings.navigateTo(settings.Route.BASIC);

[dpapad, 2017/04/13 21:56:16]

Updated test to simulate the "pop" state, now that it is required for the code
being tested to execute. Also gave <settings-animated-pages> a real |section|
name, so now I was able to remove the manual assignment to |selected| at line
22. This is better since the code being tested is supposed to set that in
currentRouteChanged.

+    settings.navigateTo(settings.Route.SEARCH_ENGINES);
+    settings.navigateToPreviousRoute();
   });
 });