Extensions WebUI: Fix a11y tests to work with Polymer 2.

Basically eliminating usage of /deep/ selectors.

Bug: 875449,860069
Change-Id: I7e53055b712ee6701f240ba6f50c9eb1918d88b1
Reviewed-on: https://chromium-review.googlesource.com/1233113Reviewed-by: Hector Carmona <hcarmona@chromium.org>
Commit-Queue: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#592474}

chrome/test/data/webui/extensions/a11y/extensions_a11y_test.js

@@ -99,7 +99,7 @@ AccessibilityTest.define('CrExtensionsA11yTest', {
   /** @override */
   tests: {
     'Accessible with No Extensions': function() {
-      let list = document.querySelector('* /deep/ #items-list');
+      let list = document.querySelector('extensions-manager').$$('#items-list');
       assertEquals(list.extensions.length, 0);
       assertEquals(list.apps.length, 0);
     }
@@ -129,7 +129,7 @@ AccessibilityTest.define('CrExtensionsA11yTestWithMultipleExensions', {
   /** @override */
   tests: {
     'Accessible with Extensions and Apps': function() {
-      let list = document.querySelector('* /deep/ #items-list');
+      let list = document.querySelector('extensions-manager').$$('#items-list');
       assertEquals(list.extensions.length, 1);
       assertEquals(list.apps.length, 3);
     },
@@ -157,8 +157,8 @@ AccessibilityTest.define('CrExtensionsShortcutA11yTestWithNoExtensions', {
   /** @override */
   tests: {
     'Accessible with No Extensions or Apps': function() {
-      let list =
-          document.querySelector('* /deep/ extensions-keyboard-shortcuts');
+      let list = document.querySelector('extensions-manager')
+                     .$$('extensions-keyboard-shortcuts');
       assertEquals(list.items.length, 0);
     },
   },
@@ -185,8 +185,8 @@ AccessibilityTest.define('CrExtensionsShortcutA11yTestWithExtensions', {
   /** @override */
   tests: {
     'Accessible with Extensions': function() {
-      let list =
-          document.querySelector('* /deep/ extensions-keyboard-shortcuts');
+      let list = document.querySelector('extensions-manager')
+                     .$$('extensions-keyboard-shortcuts');
       assertEquals(list.items.length, 1);
     },
   },
@@ -225,7 +225,9 @@ AccessibilityTest.define('CrExtensionsErrorConsoleA11yTest', {
   /** @override */
   tests: {
     'Accessible Error Console': function() {
-      assertTrue(!!document.querySelector('* /deep/ #errorsList'));
+      assertTrue(!!document.querySelector('extensions-manager')
+                       .$$('extensions-error-page')
+                       .$$('#errorsList'));
     },
   },
 });

testing/buildbot/filters/webui_polymer2_browser_tests.filter

@@ -35,11 +35,6 @@
 
 # Most of the a11y tests are failing because they use /deep/. Should be
 # addressed as part of crbug.com/860069
--CrExtensionsA11yTest.*
--CrExtensionsA11yTestWithMultipleExensions.*
--CrExtensionsErrorConsoleA11yTest.*
--CrExtensionsShortcutA11yTestWithExtensions.*
--CrExtensionsShortcutA11yTestWithNoExtensions.*
 -SettingsA11yManagePasswords.*
 -SettingsA11ySignOut.*
 -SettingsAccessibilityTest.*
@@ -135,8 +130,11 @@ CrElementsSliderTest.*
 CrElementsToastTest.*
 CrElementsToggleTest.*
 CrElementsToolbarSearchFieldTest.*
+CrExtensionsA11yTest.*
+CrExtensionsA11yTestWithMultipleExensions.*
 CrExtensionsCodeSectionTest.*
 CrExtensionsDetailViewTest.*
+CrExtensionsErrorConsoleA11yTest.*
 CrExtensionsErrorConsoleTest.*
 CrExtensionsErrorPageTest.*
 CrExtensionsItemListTest.*
@@ -149,6 +147,8 @@ CrExtensionsOptionsDialogTest.*
 CrExtensionsPackDialogTest.*
 CrExtensionsRuntimeHostPermissionsTest.*
 CrExtensionsRuntimeHostsDialogTest.*
+CrExtensionsShortcutA11yTestWithExtensions.*
+CrExtensionsShortcutA11yTestWithNoExtensions.*
 CrExtensionsShortcutInputTest.*
 CrExtensionsShortcutTest.*
 CrExtensionsSidebarTest.*