Settings to control Add Person and Browse as Guest.

chrome/browser/resources/options/browser_options.css

 /* 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. */
 
 #change-home-page-section {
   margin-left: 30px;
 }
 
 #home-page-url {
   display: inline-block;
@@ skipping 444 matching lines @@
 div[guestmode=true] :-webkit-any(
 <if expr="not chromeos">
     #searchBox,
 </if>
     #appearance-section,
     #startup-section,
     #reset-profile-settings-section) {
   display: none;
 }
 
+div[supervisedMode=true] :-webkit-any(
+    #profiles-enable-guest,
+    #profiles-enable-add-person) {
+  display: none;
+}
+
 footer {
   display: flex;
 }
 
 #version-button {
   -webkit-margin-start: auto;
   color: #999;
 }