DevTools: migrate sources panel sidebar to views.

third_party/WebKit/Source/devtools/front_end/sources/uiList.css

 /*
  * Copyright 2015 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.
  */
 
 .list-item {
     padding: 0 8px 0 0;
     position: relative;
     min-height: 18px;
     white-space: nowrap;
     line-height: 20px;
+}
+
+.list-item:not(:last-child) {
     border-bottom: 1px solid #eee;
 }
 
 .list-item:not(.ignore-hover):hover {
     background-color: #eee;
 }
 
 .list-item > .title {
     word-wrap: break-word;
     white-space: normal;
@@ skipping 38 matching lines @@
     left: 4px;
     width: 10px;
     height: 10px;
 }
 
 @media (-webkit-min-device-pixel-ratio: 1.5) {
 .list-item.selected::before {
     background-image: url(Images/smallIcons_2x.png);
 }
 } /* media */