[DevTools] Expose left and right toolbar in TabbedPane.

third_party/WebKit/Source/devtools/front_end/network/networkPanel.css

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Anthony Ricaud <rik@webkit.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 18 matching lines @@
 
 .panel.network > .toolbar {
     position: relative;
     border-bottom: 1px solid #dadada;
 }
 
 .network-details-view {
     background: rgb(203, 203, 203);
 }
 
-.network-close-button {
-    margin: auto -1px auto 4px;
-}
-
 .network-details-view-tall-header {
     margin-top: 4px;
 }
 
 .network-item-view {
     display: flex;
     background: white;
 }
 
 .network-item-preview-toolbar {
@@ skipping 202 matching lines @@
 
 .network-film-strip {
     border-bottom: solid 1px #cdcdcd;
     flex: none !important;
 }
 
 .network-blocked-urls {
     border-top: 1px solid #dadada;
     flex: 104px 0 0;
 }