Devtools: Add new row in toolbarButtonGlyphs and layout editor icon

Source/devtools/front_end/ui/section.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.
  */
 
 .section {
     position: relative;
     margin-top: 1px;
 }
 
 .section > .header {
     padding: 0 8px 0 5px;
     min-height: 18px;
     white-space: nowrap;
     background-origin: padding-box;
     background-clip: padding-box;
 }
 
 .section > .header::before {
     -webkit-user-select: none;
     background-image: url(Images/toolbarButtonGlyphs.png);
-    background-size: 352px 144px;
+    background-size: 352px 168px;
     opacity: 0.5;
     content: "a";
     color: transparent;
     text-shadow: none;
     float: left;
     width: 8px;
     margin-right: 4px;
     margin-top: 2px;
 }
 
@@ skipping 38 matching lines @@
     color: inherit;
 }
 
 .section > .properties {
     display: none;
 }
 
 .section.expanded > .properties {
     display: block;
 }