[DevTools] Use ListWidget for rendering of EditFileSystemView.

third_party/WebKit/Source/devtools/front_end/settings/frameworkBlackboxSettingsTab.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.
  */
 
 .header {
     padding: 0 0 6px;
     border-bottom: 1px solid #EEEEEE;
     font-size: 18px;
@@ skipping 31 matching lines @@
     position: relative;
     flex: auto 1 1;
 }
 
 .blackbox-pattern {
     white-space: nowrap;
     text-overflow: ellipsis;
     -webkit-user-select: none;
     color: #222;
     flex: auto;
+    overflow: hidden;
 }
 
 .blackbox-list-item.blackbox-disabled .blackbox-pattern {
     text-decoration: line-through;
 }
 
 .blackbox-behavior {
     flex: 0 0 100px;
     padding-left: 10px;
 }
@@ skipping 12 matching lines @@
 .blackbox-separator-invisible {
     visibility: hidden;
     height: 100% !important;
 }
 
 .blackbox-edit-row {
     flex: none;
     display: flex;
     flex-direction: row;
     margin: 6px 5px;
+    align-items: center;
 }
 
 .blackbox-edit-row input,
 .blackbox-edit-row select {
     width: 100%;
     text-align: inherit;
 }