DevTools: Split NetworkPanel.js

Source/devtools/front_end/network/requestHeadersView.css

 /*
  * Copyright (c) 2014 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.
  */
 
 .request-headers-view {
     -webkit-user-select: text;
     overflow: auto;
 }
@@ skipping 17 matching lines @@
     position: static;
     width: 9px;
     height: 9px;
     -webkit-mask-position: -4px -98px;
 }
 
 .request-headers-view .outline-disclosure li.parent.expanded::before {
     -webkit-mask-position: -20px -98px;
 }
 
+.request-headers-view .properties-tree li.parent {
+    margin-left: -1px;
+}
 .request-headers-view .outline-disclosure .children li {
     white-space: nowrap;
 }
 
 .request-headers-view .outline-disclosure .caution {
     margin-left: 4px;
     display: inline-block;
     font-weight: bold;
 }
 
@@ skipping 36 matching lines @@
     white-space: pre-wrap;
     word-break: break-all;
     margin-top: 1px;
 }
 
 .resource-status-image {
     margin-top: -2px;
     margin-right: 3px;
     vertical-align: middle;
 }
+
+.request-headers-view .section {
+    margin-left: -16px;
+}
+
+.request-headers-view .section.expanded .properties {
+    -webkit-padding-start: 0;
+}