DevTools: do not allow using 'this' before call into super.

third_party/WebKit/Source/devtools/front_end/accessibility/AXTreePane.js

 // Copyright 2016 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.
 
 /**
  * @constructor
  * @extends {WebInspector.AccessibilitySubPane}
  */
 WebInspector.AXTreePane = function()
 {
@@ skipping 33 matching lines @@
 };
 
 /**
  * @constructor
  * @extends {TreeElement}
  * @param {!WebInspector.AccessibilityNode} axNode
  * @param {!WebInspector.Target} target
  */
 WebInspector.AXNodeTreeElement = function(axNode, target)
 {
+    // Pass an empty title, the title gets made later in onattach.
+    TreeElement.call(this, "");
+
     /** @type {!WebInspector.AccessibilityNode} */
     this._axNode = axNode;
 
     /** @type {!WebInspector.Target} */
     this._target = target;
 
-    // Pass an empty title, the title gets made later in onattach.
-    TreeElement.call(this, "");
-
     this.selectable = false;
 };
 
 /** @type {!Object<string, string>} */
 WebInspector.AXNodeTreeElement.RoleStyles = {
     internalRole: "ax-internal-role",
     role: "ax-role",
 };
 
 WebInspector.AXNodeTreeElement.prototype = {
@@ skipping 49 matching lines @@
     _appendIgnoredNodeElement: function()
     {
         var ignoredNodeElement = createElementWithClass("span", "monospace");
         ignoredNodeElement.textContent = WebInspector.UIString("Ignored");
         ignoredNodeElement.classList.add("ax-tree-ignored-node");
         this.listItemElement.appendChild(ignoredNodeElement);
     },
 
     __proto__: TreeElement.prototype
 };