Use setSequentialFocusNavigationStartingPoint in ChromeVox

chrome/browser/resources/chromeos/chromevox/cvox2/background/automation_predicate.js

 // Copyright 2014 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 ChromeVox predicates for the automation extension API.
  */
 
 goog.provide('AutomationPredicate');
 goog.provide('AutomationPredicate.Binary');
@@ skipping 82 matching lines @@
 
 /** @type {AutomationPredicate.Unary} */
 AutomationPredicate.formField = AutomationPredicate.match({
   anyPredicate: [
     AutomationPredicate.button,
     AutomationPredicate.comboBox,
     AutomationPredicate.editText
   ],
   anyRole: [
     Role.checkBox,
+    Role.colorWell,

[David Tseng, 2016/10/27 22:42:38]

Looks like this is just input type color. Needs an output rule (note fo me).

     Role.listBox,
     Role.slider,
-    Role.tab,
+    Role.switch,

[David Tseng, 2016/10/27 22:42:38]

Didn't know about this role...
this one needs an output rule to mirror checkboxes (this is more of a note for
me).

[dmazzoni, 2016/10/27 22:56:02]

What would you think if automation exposed a much smaller subset of roles,
plus a roleDescription?

We could map switch and checkbox to the same role, but with a different
role description. All the landmark roles would be the same, too - just one
role "landmark" plus a role description with the specific localized name.

     Role.tree
   ]
 });
 
 /** @type {AutomationPredicate.Unary} */
+AutomationPredicate.control = AutomationPredicate.match({
+  anyPredicate: [
+    AutomationPredicate.formField,
+  ],
+  anyRole: [
+    Role.disclosureTriangle,
+    Role.menuItem,
+    Role.menuItemCheckBox,
+    Role.menuItemRadio,
+    Role.menuListOption,
+    Role.scrollBar,
+    Role.tab
+  ]
+});
+
+/** @type {AutomationPredicate.Unary} */
+AutomationPredicate.linkOrControl = AutomationPredicate.match({
+  anyPredicate: [
+    AutomationPredicate.control
+  ],
+  anyRole: [
+    Role.link
+  ]
+});
+
+/** @type {AutomationPredicate.Unary} */
 AutomationPredicate.landmark = AutomationPredicate.roles([
     Role.application,
     Role.banner,
     Role.complementary,
     Role.contentInfo,
     Role.form,
     Role.main,
     Role.navigation,
     Role.region,
     Role.search]);
@@ skipping 304 matching lines @@
  * @param {number} level 1-6
  * @return {AutomationPredicate.Unary}
  */
 AutomationPredicate.makeHeadingPredicate = function(level) {
   return function(node) {
     return node.role == Role.heading && node.hierarchicalLevel == level;
   };
 };
 
 });  // goog.scope