Set keys for SwitchAccessEventHandler to capture using accessibiltyPrivate API

chrome/browser/resources/chromeos/switch_access/keyboard_handler.js

Index: chrome/browser/resources/chromeos/switch_access/keyboard_handler.js
diff --git a/chrome/browser/resources/chromeos/switch_access/keyboard_handler.js b/chrome/browser/resources/chromeos/switch_access/keyboard_handler.js
index 901690f594341130f35ad6a27d4705825c56683c..7231a6b6dc21641371c1d8709cff4c6de7828ff8 100644
--- a/chrome/browser/resources/chromeos/switch_access/keyboard_handler.js
+++ b/chrome/browser/resources/chromeos/switch_access/keyboard_handler.js
@@ -28,6 +28,10 @@ KeyboardHandler.prototype = {
    * @private
    */
   init_: function() {
+    // Capture keycodes for keys 1 through 4, and 6 through 9.
+    let keyCodes = ['1', '2', '3', '4', '6', '7', '8', '9'].map(
+        key => key.charCodeAt(0));

[Devlin, 2017/05/31 20:41:15]

Note: arrow functions (last I checked) weren't available in all versions of iOS.
 I'm assuming this code is only run on CrOS; is that accurate?

[elichtenberg, 2017/06/01 19:55:27]

Yep, this is just run on CrOS.

+    chrome.accessibilityPrivate.setSwitchAccessKeys(keyCodes);
     document.addEventListener('keyup', this.handleKeyEvent_.bind(this));
   },