DevTools: Add a checkbox to enable async stacks in the sidebar header.

Source/devtools/front_end/sidebarPane.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 70 matching lines @@
     background-clip: padding;
     margin-top: -1px;
 }
 
 .sidebar-pane-title:active {
     background-color: rgb(204, 204, 204);
     border-top: 1px solid rgb(178, 178, 178);
     border-bottom: 1px solid rgb(178, 178, 178);
 }
 
-.placard-group::before,
 .sidebar-pane-title::before {
     background-image: url(Images/statusbarButtonGlyphs.png);
     background-size: 320px 120px;
     opacity: 0.5;
     float: left;
     width: 11px;
     height: 11px;
     margin-right: 2px;
     content: "a";
     color: transparent;
     position: relative;
     top: 3px;
 }
 
 @media (-webkit-min-device-pixel-ratio: 1.5) {
-.placard-group::before,
 .sidebar-pane-title::before {
     background-image: url(Images/statusbarButtonGlyphs2x.png);
 }
 } /* media */
 
-.placard-group::before,
 .sidebar-pane-title::before {
     background-position: -4px -96px;
 }
 
-.placard-group.expanded::before,
 .sidebar-pane-title.expanded::before {
     background-position: -20px -96px;
 }
 
 .sidebar-pane-toolbar {
     line-height: 18px;
     left: 0;
     right: 4px;
     top: 0;
     height: 20px;
     position: absolute;
     pointer-events: none;
 }
 
 .sidebar-pane-toolbar > * {
     pointer-events: auto;
 }
 
-.sidebar-pane-toolbar > .pane-title-button {
+.sidebar-pane-toolbar > .pane-title-button,
+.sidebar-pane-toolbar > label {
     float: right;
-    width: 23px;
     height: 17px;
-    color: transparent;
     background-color: transparent;
     border: none;
     background-repeat: no-repeat;
     margin: 1px 0 0 0;
     padding: 0;
     border-radius: 0;
     -webkit-appearance: none;
 }
 
+.sidebar-pane-toolbar > .pane-title-button {
+    width: 23px;
+    color: transparent;
+}
+
 .sidebar-pane-toolbar > .pane-title-button:hover {
     background-position: -23px 0;
 }
 
 .sidebar-pane-toolbar > .pane-title-button:active,
 .sidebar-pane-toolbar > .pane-title-button.toggled {
     background-position: -46px 0;
 }
 
 .sidebar-pane-toolbar > .pane-title-button.add {
     background-image: url(Images/paneAddButtons.png);
 }
 
 .sidebar-pane-toolbar > .pane-title-button.element-state {
     background-image: url(Images/paneElementStateButtons.png);
 }
 
 .sidebar-pane-toolbar > .pane-title-button.refresh {
     background-image: url(Images/paneRefreshButtons.png);
 }
 
+.sidebar-pane-toolbar > label > input {
+    vertical-align: -2px;
+}
+
+.sidebar-pane-toolbar > label.scripts-callstack-async {
+    margin-right: 5px;
+}
+
 .sidebar-pane-subtitle {
     position: absolute;
     right: 0;
 }
 
 body.platform-windows .sidebar-pane-subtitle {
     padding-top: 1px;
 }
 
 .sidebar-pane-subtitle input,
 .section > .header input[type=checkbox] {
     height: 1em;
     width: 1em;
     margin-left: 0;
     margin-top: 0;
     margin-bottom: 0.25em;
     vertical-align: bottom;
 }