DevTools: Use real focus in TreeOutline

third_party/WebKit/Source/devtools/front_end/network/RequestHeadersView.js

 /*
  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) IBM Corp. 2009  All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * 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
@@ skipping 18 matching lines @@
  */
 
 /**
  * @unrestricted
  */
 Network.RequestHeadersView = class extends UI.VBox {
   /**
    * @param {!SDK.NetworkRequest} request
    */
   constructor(request) {
-    super();
+    super(true);
     this.registerRequiredCSS('network/requestHeadersView.css');
     this.element.classList.add('request-headers-view');
 
     this._request = request;
     this._decodeRequestParameters = true;
     this._showRequestHeadersText = false;
     this._showResponseHeadersText = false;
 
     var root = new UI.TreeOutlineInShadow();
     root.registerRequiredCSS('network/requestHeadersTree.css');
     root.element.classList.add('request-headers-tree');
-    root.setFocusable(false);
     root.makeDense();
     root.expandTreeElementsWhenArrowing = true;
     this.element.appendChild(root.element);
 
     var generalCategory = new Network.RequestHeadersView.Category(root, 'general', Common.UIString('General'));
     generalCategory.hidden = false;
     this._urlItem = generalCategory.createLeaf();
     this._requestMethodItem = generalCategory.createLeaf();
     this._statusCodeItem = generalCategory.createLeaf();
     this._remoteAddressItem = generalCategory.createLeaf();
@@ skipping 470 matching lines @@
     this._expandedSetting.set(true);
   }
 
   /**
    * @override
    */
   oncollapse() {
     this._expandedSetting.set(false);
   }
 };