Fixes undefined access in group node's location getter

R=anastasi@google.com, dmazzoni@chromium.org

AX-Relnotes: n/a
Fixed: 1126707
Change-Id: I812918d101fba188b7c6f488bb9658b571fe612b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2410347
Commit-Queue: David Tseng <dtseng@chromium.org>
Reviewed-by: Akihiro Ota <akihiroota@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806864}

chrome/browser/resources/chromeos/accessibility/switch_access/BUILD.gn

@@ -105,6 +105,7 @@ js2gtest("switch_access_extjs_tests") {
     "navigation_manager_test.js",
     "nodes/basic_node_test.js",
     "nodes/desktop_node_test.js",
+    "nodes/group_node_test.js",
     "nodes/tab_node_test.js",
     "switch_access_predicate_test.js",
     "text_navigation_manager_test.js",

chrome/browser/resources/chromeos/accessibility/switch_access/nodes/group_node.js

@@ -35,7 +35,8 @@ class GroupNode extends SAChildNode {
 
   /** @override */
   get location() {
-    const childLocations = this.children_.map(c => c.location);
+    const childLocations =
+        this.children_.filter(c => c.isValidAndVisible()).map(c => c.location);
     return RectUtil.unionAll(childLocations);
   }
 

chrome/browser/resources/chromeos/accessibility/switch_access/nodes/group_node_test.js

+// Copyright 2020 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.
+
+GEN_INCLUDE(['../switch_access_e2e_test_base.js']);
+
+/** Test fixture for the node wrapper type. */
+SwitchAccessGroupNodeTest = class extends SwitchAccessE2ETest {};
+
+TEST_F('SwitchAccessGroupNodeTest', 'NodesRemoved', function() {
+  const website = `<button></button>`;
+  this.runWithLoadedTree(website, (desktop) => {
+    const button = desktop.find({role: chrome.automation.RoleType.BUTTON});
+    assertNotEquals(undefined, button);
+
+    const root = new BasicRootNode(desktop);
+    assertEquals(0, root.children_.length);
+
+    // Add a group child which has two buttons (same underlying automation
+    // node).
+    const buttonNode = new BasicNode(button, root);
+    const otherButtonNode = new BasicNode(button, root);
+    const groupNode = new GroupNode([buttonNode, otherButtonNode]);
+    root.children_ = [groupNode];
+
+    // Try asking for the location of the group.
+    assertTrue(!!groupNode.location);
+
+    // Try again after clearing one of the button's underlying node.
+    buttonNode.baseNode_ = undefined;
+    assertTrue(!!groupNode.location);
+  });
+});