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 438 matching lines @@
 
 #accessibility-autoclick label + select {
   /* Same as .controlled-setting-with-label > input + span. */
   -webkit-margin-start: 0.6em;
 }
 
 div[guestmode=true] :-webkit-any(
 <if expr="not chromeos">
     #searchBox,
 </if>
     #appearance-section,

[Evan Stade, 2014/09/04 17:55:36]

I know I keep vacillating on this -- sorry for that. But it strikes me that for
both this rule block and the one you're now adding, the list of IDs indicates
you should probably be using a class. It would make sense to introduce a new
class, e.g. exclude-in-guest-mode, so your rule here is pretty simple:

div[guestmode=true] .exclude-in-guest-mode {
  display: none;
}

This also makes the html more readable --- you don't have to trace through
multiple files to figure out when this thing is shown, because the class name is
more descriptive for this purpose than an ID.

[Mike Lerman, 2014/09/04 20:58:51]

I'm not sure I want to do this change for this CL. For the current list, I'd
have a difficulty with the chromeos exclusion, which means I'd either need to
create a .exclude-in-guest-mode and a .exclude-in-guest-mode-except-chromeos or
have separate code for #searchBox, which then means I have a class for just
three objects, when the current OS tagged list conveys the objective nicely.

The other big reason is there's already a guest-visibility="disabled" tag, which
from what I could gather only take effect in ChromeOS. Adding a similarly named
class would be confusing. What would be better (and I can open a bug to do in a
later CL) would be to have a more coherent design and flag/class to control
visibility. Currently, some things start hidden, and others don't; some are
hidden in CSS, some in JS, and ChromeOS has its own solution. I'd be happy (in
M40/41) to take a stab at figuring out the half dozen use cases, coming up with
nice syntax, and implementing that.

     #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;
 }