Devtools: Add new row in toolbarButtonGlyphs and layout editor icon

Source/devtools/front_end/inspectorStyle.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 193 matching lines @@
 }
 
 ol.outline-disclosure:focus li.selected * {
     color: inherit;
 }
 
 .outline-disclosure li::before {
     float: left;
     -webkit-user-select: none;
     -webkit-mask-image: url(Images/toolbarButtonGlyphs.png);
-    -webkit-mask-size: 352px 144px;
+    -webkit-mask-size: 352px 168px;
     content: "a";
     color: transparent;
     text-shadow: none;
     position: relative;
     top: 2px;
     margin-right: 1px;
     width: 10px;
     height: 10px;
 }
 
@@ skipping 133 matching lines @@
 .sidebar-tree.some-expandable > .sidebar-tree-item:not(.parent) .icon {
     margin-left: 16px;
 }
 
 .sidebar-tree-item .disclosure-button {
     float: left;
     width: 10px;
     height: 10px;
     border: 0;
     -webkit-mask-image: url(Images/toolbarButtonGlyphs.png);
-    -webkit-mask-size: 352px 144px;
+    -webkit-mask-size: 352px 168px;
     -webkit-appearance: none;
     background-color: rgba(0, 0, 0, 0.75);
     position: relative;
     top: 10px;
 }
 
 @media (-webkit-min-device-pixel-ratio: 1.5) {
 .sidebar-tree-item .disclosure-button {
     -webkit-mask-image: url(Images/toolbarButtonGlyphs_2x.png);
 }
@@ skipping 249 matching lines @@
 }
 
 body.inactive select.chrome-select,
 .chrome-select:disabled {
     background-image: -webkit-image-set(url(Images/chromeDisabledSelect.png) 1x, url(Images/chromeDisabledSelect_2x.png) 2x), linear-gradient(#f1f1f1, #f1f1f1 38%, #e6e6e6);
     border-color: rgba(80, 80, 80, 0.2);
     box-shadow: 0 1px 0 rgba(80, 80, 80, 0.08),
     inset 0 1px 2px rgba(255, 255, 255, 0.75);
     color: #aaa;
 }