DevTools: highlight attributes on selected DOM node

Source/devtools/front_end/elements/elementsTreeOutline.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.
  */
 
 .elements-disclosure {
     width: 100%;
     display: inline-block;
     line-height: normal;
@@ skipping 286 matching lines @@
 }
 
 ol:hover > li > .elements-tree-shortcut-link {
     display: initial;
 }
 
 .elements-tree-shortcut-link {
     color: rgb(87, 87, 87);
     display: none;
 }
+
+ol:focus li.selected .webkit-html-tag {
+    color: #a5a5a5;
+}
+
+ol:focus li.selected .webkit-html-tag-name,
+ol:focus li.selected .webkit-html-close-tag-name,
+ol:focus li.selected .webkit-html-attribute-value,
+ol:focus li.selected .webkit-html-external-link,
+ol:focus li.selected .webkit-html-resource-link {
+    color: white;
+}
+
+ol:focus li.selected .webkit-html-attribute-name {
+    color: #ccc;
+}