Add a button to open TalkBack settings in chrome://settings.

chrome/browser/resources/options/browser_options.html

 <div id="settings" class="page" hidden>
   <header>
     <h1 i18n-content="settingsTitle"></h1>
   </header>
   <include src="automatic_settings_reset_banner.html">
 <if expr="chromeos">
   <link rel="import" href="chrome://resources/cr_elements/network/cr_network_icon.html">
   <link rel="import" href="chrome://resources/cr_elements/network/cr_onc_types.html">
   <include src="secondary_user_banner.html">
   <section id="network-section-cros">
@@ skipping 878 matching lines @@
               metric="Options_AccessibilitySpokenFeedback">
           <span>
             <span i18n-content="accessibilitySpokenFeedback"></span>
             <span class="controlled-setting-indicator"
                 pref="settings.accessibility"></span>
           </span>
         </label>
         <div id="accessibility-settings" hidden>
           <button id="accessibility-settings-button"
             i18n-content="accessibilitySettings"></button>
+          <button id="talkback-settings-button"
+            i18n-content="accessibilityTalkBackSettings"></button>
         </div>
       </div>
     </div>
     <div class="option-name">
       <div class="checkbox controlled-setting-with-label">
         <label>
           <input
               id="accessibility-screen-magnifier-check"
               pref="settings.a11y.screen_magnifier" type="checkbox"
               metric="Options_AccessibilityScreenMagnifier">
@@ skipping 219 matching lines @@
       </button>
     </div>
   </section>
   </div>  <!-- advanced-settings-container -->
   </div>  <!-- advanced-settings -->
   <footer id="advanced-settings-footer">
     <a is="action-link" id="advanced-settings-expander"
         i18n-content="showAdvancedSettings"></a>
   </footer>
 </div>