UI polish for certificate viewer

chrome/browser/resources/quota_internals/main.css

 /*
 Copyright (c) 2011 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 {
+  /* Remove body margin as the general tabpanels do not have outer border. */
+  margin: 0;
+}
+
 th, td {
   padding-left: 0.5em;
   padding-right: 0.5em;
   text-align: center;
 }
 
 #tree-view-container {
   float: left;
   min-width: 15em;
   width: 20%;
 }
 
 tr:nth-child(odd) {
   background: #eeeeff;
 }
 
 .tree-item:not([may-have-children]) > .tree-row > .tree-label {
   background-image: url("../shared/images/icon_file.png");
 }