A11y improvements for quick unlock settings

chrome/browser/resources/options/chromeos/quick_unlock_configure_overlay.html

Index: chrome/browser/resources/options/chromeos/quick_unlock_configure_overlay.html
diff --git a/chrome/browser/resources/options/chromeos/quick_unlock_configure_overlay.html b/chrome/browser/resources/options/chromeos/quick_unlock_configure_overlay.html
index abc1b77c22743567f92dc33919b41e953a13d93b..07904cc64363cffc72d06806cc8c17ce8855dfdc 100644
--- a/chrome/browser/resources/options/chromeos/quick_unlock_configure_overlay.html
+++ b/chrome/browser/resources/options/chromeos/quick_unlock_configure_overlay.html
@@ -1,6 +1,15 @@
 <div id="quick-unlock-configure-overlay" class="page" hidden>
   <div class="close-button"></div>
   <h1 i18n-content="lockScreenTitle"></h1>
-  <settings-lock-screen prefs="{{prefs}}">
+  <settings-lock-screen prefs="{{prefs}}" tabindex=0>
   </settings-lock-screen>
+
+  <div class="action-area">
+    <div class="button-strip">
+      <paper-button class="action-button"
+                    id="screen-lock-done">
+        $i18n{done}
+      </paper-button>
+    </div>
+  </div>
 </div>