Add links to more options pages for Chrome OS accessibility features

chrome/app/settings_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Settings-specific strings (included from generated_resources.grd). -->
 <grit-part>
   <!-- Main Page -->
   <if expr="chromeos">
     <message name="IDS_SETTINGS_SECONDARY_USER_BANNER" desc="Banner displayed in settings page when the user is secondary in a multi-profile session.">
       Some settings belonging to <ph name="PRIMARY_EMAIL">$1<ex>john@google.com</ex></ph> are being shared with you. These settings only affect your account when using multiple sign-in.
     </message>
   </if>
 
@@ skipping 144 matching lines @@
     </message>
     <message name="IDS_SETTINGS_HIGH_CONTRAST_LABEL" desc="Label for checkbox which enables high-contrast UI.">
       Use high contrast mode
     </message>
     <message name="IDS_SETTINGS_STICKY_KEYS_LABEL" desc="Label for checkbox which enables sticky keys, with an explanation of the term 'sticky keys'.">
       Enable sticky keys (to perform keyboard shortcuts by typing them sequentially)
     </message>
     <message name="IDS_SETTINGS_CHROMEVOX_LABEL" desc="Label for checkbox which enables ChromeVox, with a description of what ChromeVox is.">
       Enable ChromeVox (spoken feedback)
     </message>
+    <message name="IDS_SETTINGS_CHROMEVOX_OPTIONS_LABEL" desc="Label for button to open ChromeVox options.">
+      ChromeVox Options
+    </message>
     <message name="IDS_SETTINGS_SCREEN_MAGNIFIER_LABEL" desc="Label for checkbox which enables the screen magnifier">
       Enable screen magnifier
     </message>
     <message name="IDS_SETTINGS_TAP_DRAGGING_LABEL" desc="Label for checkbox which enables tap dragging.">
       Enable tap dragging
     </message>
     <message name="IDS_SETTINGS_CLICK_ON_STOP_LABEL" desc="Label for checkbox which enables automatically clicking when the mouse pointer stops.">
       Automatically click when the mouse pointer stops
     </message>
     <message name="IDS_SETTINGS_DELAY_BEFORE_CLICK_LABEL" desc="Label for dropdown menu which contains various time delays for clicks.">
@@ skipping 2770 matching lines @@
       System
     </message>
     <message name="IDS_SETTINGS_SYSTEM_HARDWARE_ACCELERATION_LABEL" desc="Label for the checkbox that forces Chrome to render via hardware acceleration (GPU) when available.">
       Use hardware acceleration when available
     </message>
     <message name="IDS_SETTINGS_SYSTEM_PROXY_SETTINGS_BUTTON" desc="Text for the button that changes a user's network proxy settings.">
       Change proxy settings
     </message>
   </if>
 </grit-part>