Files.app: Updated CSS to remove white border lines from the default action dialog.

chrome/browser/resources/file_manager/css/file_manager.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. */
 
 html {
   height: 100%;
 }
 
 html.col-resize * {
   cursor: col-resize !important;
@@ skipping 1694 matching lines @@
   border-right-width: 0;
   height: 39px;
   padding-bottom: 1px;
   padding-top: 1px;
 }
 
 body[new-ui] #list-container li.table-row {
   height: 30px;
 }
 
+body[new-ui] #default-actions-list li {
+  border-style: none;
+}
+
 /* The icon in the name column. See file_types.css for specific icons. */
 .detail-icon {
   height: 24px;
   width: 24px;
 }
 
 .metadata-item {
   -webkit-box-flex: 1;
   -webkit-box-orient: horizontal;
   -webkit-padding-start: 8px;
@@ skipping 638 matching lines @@
 body[new-ui] #iframe-drag-area {
   -webkit-app-region: drag;
   height: 45px;
   left: 64px;
   position: absolute;
   right: 70px;
   top: 0;
   width: auto;
   z-index: 101;
 }