Disable modifying extensions when in managed mode.

chrome/browser/resources/shared/css/chrome_shared.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. */
 
 /* This file holds CSS that should be shared, in theory, by all user-visible
  * chrome:// pages. */
 
 @import url("chrome://resources/css/widgets.css");
 <if expr="pp_ifdef('chromeos')">
   @import url("chrome://resources/css/chromeos/ui_account_tweaks.css");
@@ skipping 87 matching lines @@
 
 /* WebKit does not honor alignment for text specified via placeholder attribute.
  * This CSS is a workaround. Please remove once WebKit bug is fixed.
  * https://bugs.webkit.org/show_bug.cgi?id=63367
  */
 html[dir='rtl'] input.weakrtl::-webkit-input-placeholder,
 html[dir='rtl'] .weakrtl input::-webkit-input-placeholder {
   direction: rtl;
 }
 
+/* Styles for a hideable notification banner at the top of a page.
+ * See the Options page .managed-prefs-banner for a usage example.
+ */

[Patrick Dubroy, 2012/06/18 12:13:01]

It seems like a lot of this code should be in uber_shared.css, not
chrome_shared.css. Ideally, anything for the visual styling of the banner should
be in the latter, and everything for positioning and hiding/showing should be in
the former.

[Pam (message me for reviews), 2012/06/18 18:26:00]

Moved the whole block to uber_shared.css following our discussion.

+.page.showing-banner {
+  margin-top: 45px;

[Patrick Dubroy, 2012/06/18 12:13:01]

This should be in uber_shared.css, for example.

+}
+
+.main-page-banner {
+  background-color: white;

[Patrick Dubroy, 2012/06/18 12:13:01]

Is this necessary?

[Pam (message me for reviews), 2012/06/18 18:26:00]

I don't know -- I'm just moving this from options_page.css and am reluctant to
remove it.

+  width: 100%;
+  z-index: 2;
+}
+
+.page:not(.showing-banner) .main-page-banner {
+  display: none;
+}
+
+.main-page-banner-gradient {

[Patrick Dubroy, 2012/06/18 12:13:01]

I'd move this to chrome_shared.css and rename the class to just banner-gradient.

+  background: -webkit-linear-gradient(rgb(255, 242, 183),
+                                      rgb(250, 230, 145));
+  border: 1px solid rgb(201, 189, 141);
+  border-radius: 3px;
+  height: 25px;
+  margin: 9px 9px 0 9px;
+}
+
+.main-page-banner .main-page-banner-gradient {
+  -webkit-margin-end: 20px;
+  -webkit-margin-start: 0;
+  margin-bottom: 9px;
+}
+
+.main-page-banner-text {
+  background-image: url('chrome://theme/IDR_MANAGED');
+  background-position: 5px center;
+  background-repeat: no-repeat;
+  display: block;
+  line-height: 24px;
+  padding-left: 26px;
+}
+
+.main-page-banner.clickable:active .main-page-banner-text {
+  background: -webkit-linear-gradient(rgb(250, 230, 145),
+                                      rgb(255, 242, 183));
+}
+
 /* Rules to make it easier to hit targets when using a coarse pointer like
  * a touch screen.
  */
 @media (pointer:coarse) {
   list input[type='input'],
   list input[type='password'],
   list input[type='search'],
   list input[type='text'],
   list input[type='url'] {
     margin: 0;
@@ skipping 30 matching lines @@
 
   list button:not(.custom-appearance):not(.link-button),
   list input[type=button]:not(.custom-appearance),
   list input[type=submit]:not(.custom-appearance),
   list select {
     margin: 0;
     padding-bottom: 0;
     padding-top: 3px;
   }
 }