Fix style on network details to put scrollbar in tab contents.

chrome/browser/resources/options2/chromeos/internet_detail.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. */
 
 /* Force tab strip to extend to the left and right edges of the window. */
 #internet-details-content-area {
+  -webkit-box-orient: vertical;
+  display: -webkit-box;
   margin: 0 !important;
   padding: 0 !important;
 }
 
 #network-details-header {
   -webkit-padding-start: 20px;
   margin: 0;
   padding-bottom: 18px;
   padding-top: 32px;
 }
@@ skipping 23 matching lines @@
 #details-tab-strip.subpages-nav-tabs > .active-tab {
   -webkit-box-shadow: 8px -8px 12px -6px rgb(240,240,240);
   border-left: 1px solid #ddd;
   border-right: 1px solid #ddd;
   border-top: 1px solid #ddd;
 }
 
 /* Fix the height of the subpages so that the dialog does not resize when the
    user switches tabs. */
 #internet-details-content-area > .subpages-tab-contents {
+  -webkit-box-flex: 1;
+  -webkit-box-sizing: border-box;
   -webkit-padding-end: 10px;
   height: 350px;
   min-width: 480px;
   overflow-y: auto;
 }
 
 #ipConfigList {
   min-height: 96px !important;
 }
 
 /* Minimum and maximum height are integer multiples of the height of a list
    entry. */
 #ignoredHostList {
   -webkit-margin-start: 0;
   border: solid 1px #999;
   max-height: 128px;
   min-height: 64px;
   width: 400px;
 }
 
 #newHost {
   -webkit-margin-start: 0;
   margin-top: 8px;
 }