Move section CSS to uber_shared to share with other uber pages.

chrome/browser/resources/options2/options_page.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. */
 
 body {
   position: relative;
 }
 
 #main-content {
   bottom: 0;
@@ skipping 134 matching lines @@
 
 #page-container .page.showing-banner {
   margin-top: 45px;
 }
 
 .page list {
   /* Min height is a multiple of the list item height (32) */
   min-height: 192px;
 }
 
-section {
-  -webkit-padding-start: 18px;
-  margin-bottom: 24px;
-  margin-top: 8px;
-  max-width: 600px;
-}
-
-section:last-of-type {
-  margin-bottom: 0;
-}
-
-section > h3 {
-  -webkit-margin-start: -18px;
-}
-
-section > div:only-of-type {
-  -webkit-box-flex: 1;
-}
-
 .option {
   margin-top: 0;
 }
 
 .transparent {
   opacity: 0;
 }
 
 .touch-slider {
   -webkit-appearance: slider-horizontal;
@@ skipping 375 matching lines @@
       url('chrome://theme/IDR_CONTROLLED_SETTING_RECOMMENDED_LARGE');
 }
 
 html[dir='rtl'] .controlled-setting-bubble-text {
   background-position: right top;
 }
 
 .controlled-setting-bubble-action {
   padding: 0 !important;
 }