DevTools: Use real focus in TreeOutline

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);
 }
 
@@ skipping 144 matching lines @@
 li .inspect-dom-node {
     background-color: #5a5a5a;
     padding: 0;
     margin-left: 5px;
     border: 0;
     display: none;
     position: relative;
     top: 2px;
 }
 
-.tree-outline:focus li.selected .inspect-dom-node {
+.tree-outline li.selected:focus .inspect-dom-node {
     background-color: white;
 }