Use setSequentialFocusNavigationStartingPoint in ChromeVox

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

Index: chrome/browser/resources/chromeos/chromevox/cvox2/background/automation_predicate.js
diff --git a/chrome/browser/resources/chromeos/chromevox/cvox2/background/automation_predicate.js b/chrome/browser/resources/chromeos/chromevox/cvox2/background/automation_predicate.js
index 76a901891b599094885f44098c624d00fda7cefd..a9b70e4eb34e730a9d23469d51ed4ede8ce8b634 100644
--- a/chrome/browser/resources/chromeos/chromevox/cvox2/background/automation_predicate.js
+++ b/chrome/browser/resources/chromeos/chromevox/cvox2/background/automation_predicate.js
@@ -100,14 +100,41 @@ AutomationPredicate.formField = AutomationPredicate.match({
   ],
   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,