Add 5 experimental accessibility features on Chrome OS.

chrome/common/extensions/api/chromeos_info_private.json

 // Copyright (c) 2012 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.
 
 [
   {
     "namespace": "chromeosInfoPrivate",
     "description": "none",
     "compiler_options": {
       "implemented_in": "chrome/browser/chromeos/extensions/info_private_api.h"
     },
     "types": [
       {
         "id": "PropertyName",
         "type": "string",
         "enum": ["timezone",
                  "a11yLargeCursorEnabled",
                  "a11yStickyKeysEnabled",
                  "a11ySpokenFeedbackEnabled",
                  "a11yHighContrastEnabled",
                  "a11yScreenMagnifierEnabled",
                  "a11yAutoClickEnabled",
                  "a11yVirtualKeyboardEnabled",
+                 "a11yCaretHighlightEnabled",
+                 "a11yCursorHighlightEnabled",
+                 "a11yFocusHighlightEnabled",
+                 "a11ySelectToSpeakEnabled",
+                 "a11ySwitchAccessEnabled",
                  "sendFunctionKeys"],
         "description": "Chrome OS system property name"
       }
     ],
     "functions": [
       {
         "name": "get",
         "description": "Fetches customization values for the given property names. See property names in the declaration of the returned dictionary.",
         "type": "function",
         "parameters": [
@@ skipping 56 matching lines @@
           {
             "name": "propertyValue",
             "type": "any",
             "description": "Chrome OS system property value"
           }
         ]
       }
     ]
   }
 ]