Unframe chrome://extensions as it's the last (and only) uber item

chrome/browser/resources/policy_android.css

 /* Copyright 2013 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. */
 
-body.uber-frame {
+body {
   -webkit-margin-start: 0;
 }
 
-body.uber-frame > .page {
+body > .page {
   -webkit-margin-end: 0;
   -webkit-padding-end: 10px;
   -webkit-padding-start: 10px;
   min-width: 0;
 }
 
 #filter-overlay {
   padding-bottom: 0;
   position: fixed;
   z-index: 4;
 }
 
-body.uber-frame header {
+body header {
   left: 0;
   max-width: none;
   min-width: 0;
 }
 
-body.uber-frame header > h1 {
+body header > h1 {
   margin-left: 10px;
 }
 
-body.uber-frame section {
+body section {
   -webkit-padding-start: 0;
   max-width: none;
 }
 
-body.uber-frame section > h3 {
+body section > h3 {
   -webkit-margin-start: 0;
 }
 
 #status-box-container {
   display: -webkit-flex;
 }
 
 fieldset {
   border: 1px solid rgb(217, 217, 217);
   display: inline;
@@ skipping 77 matching lines @@
 }
 
 section.empty > table {
   display: none;
 }
 
 section:not(.empty) > div.no-policies-set {
   display: none;
 }
 
-body.uber-frame * section.policy-table-section {
+body * section.policy-table-section {
   padding-bottom: 10px;
 }
 
 th,
 td {
   border: 1px solid rgb(217, 217, 217);
   padding: 4px;
 }
 
 th {
@@ skipping 42 matching lines @@
 
 tbody:not(.has-overflowed-value) > tr.expanded-value-container,
 tbody:not(.show-overflowed-value) > tr.expanded-value-container {
   display: none;
 }
 
 td.expanded-value {
   white-space: pre;
   word-wrap: break-word;
 }