Add ARIA panel to accessibility sidebar pane

third_party/WebKit/Source/devtools/front_end/accessibility/accessibilityNode.css

 /*
  * Copyright 2015 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.
  */
 
+.sidebar-pane.accessibility-computed {
+    background-color: rgba(0, 0, 0, 0.03);
+}
+
 .ax-computed-text {
     background-image: url(Images/speech.png);
     background-repeat: no-repeat;
     background-position: 0px center;
     background-size: 12px;
     padding-left: 17px;
 }
 
 .ax-computed-text div {
     display: inline-block;
@@ skipping 81 matching lines @@
     margin-left: -11px;
 }
 
 .ax-value-string {
     color: rgb(200, 0, 0);
 }
 
 .sidebar-pane-stack .sidebar-pane {
     padding-left: 4px;
 }