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

third_party/WebKit/Source/devtools/front_end/elements/ElementsTreeOutline.js

 /*
  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2008 Matt Lilek <webkit@mattlilek.com>
  * Copyright (C) 2009 Joseph Pecoraro
  *
  * 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 19 matching lines @@
 
 /**
  * @constructor
  * @extends {TreeOutline}
  * @param {!WebInspector.DOMModel} domModel
  * @param {boolean=} omitRootDOMNode
  * @param {boolean=} selectEnabled
  */
 WebInspector.ElementsTreeOutline = function(domModel, omitRootDOMNode, selectEnabled)
 {
+    TreeOutline.call(this);
+
     this._domModel = domModel;
     this._treeElementSymbol = Symbol("treeElement");
-
-    var element = createElement("div");
-
-    this._shadowRoot = WebInspector.createShadowRootWithCoreStyles(element, "elements/elementsTreeOutline.css");
+    var shadowContainer = createElement("div");
+    this._shadowRoot = WebInspector.createShadowRootWithCoreStyles(shadowContainer, "elements/elementsTreeOutline.css");
     var outlineDisclosureElement = this._shadowRoot.createChild("div", "elements-disclosure");
 
-    TreeOutline.call(this);
     this._element = this.element;
     this._element.classList.add("elements-tree-outline", "source-code");
     this._element.addEventListener("mousedown", this._onmousedown.bind(this), false);
     this._element.addEventListener("mousemove", this._onmousemove.bind(this), false);
     this._element.addEventListener("mouseleave", this._onmouseleave.bind(this), false);
     this._element.addEventListener("dragstart", this._ondragstart.bind(this), false);
     this._element.addEventListener("dragover", this._ondragover.bind(this), false);
     this._element.addEventListener("dragleave", this._ondragleave.bind(this), false);
     this._element.addEventListener("drop", this._ondrop.bind(this), false);
     this._element.addEventListener("dragend", this._ondragend.bind(this), false);
     this._element.addEventListener("contextmenu", this._contextMenuEventFired.bind(this), false);
     this._element.addEventListener("clipboard-beforecopy", this._onBeforeCopy.bind(this), false);
     this._element.addEventListener("clipboard-copy", this._onCopyOrCut.bind(this, false), false);
     this._element.addEventListener("clipboard-cut", this._onCopyOrCut.bind(this, true), false);
     this._element.addEventListener("clipboard-paste", this._onPaste.bind(this), false);
 
     outlineDisclosureElement.appendChild(this._element);
-    this.element = element;
+    this.element = shadowContainer;
 
     this._includeRootDOMNode = !omitRootDOMNode;
     this._selectEnabled = selectEnabled;
     /** @type {?WebInspector.DOMNode} */
     this._rootDOMNode = null;
     /** @type {?WebInspector.DOMNode} */
     this._selectedDOMNode = null;
 
     this._visible = false;
 
-    this._popoverHelper = new WebInspector.PopoverHelper(this._element, this._getPopoverAnchor.bind(this), this._showPopover.bind(this));
+    this._popoverHelper = new WebInspector.PopoverHelper(this._element);
+    this._popoverHelper.initializeCallbacks(this._getPopoverAnchor.bind(this), this._showPopover.bind(this));
     this._popoverHelper.setTimeout(0, 100);
 
     /** @type {!Map<!WebInspector.DOMNode, !WebInspector.ElementsTreeOutline.UpdateRecord>} */
     this._updateRecords = new Map();
     /** @type {!Set<!WebInspector.ElementsTreeElement>} */
     this._treeElementsBeingUpdated = new Set();
 
     this._domModel.addEventListener(WebInspector.DOMModel.Events.MarkersChanged, this._markersChanged, this);
     this._showHTMLCommentsSetting = WebInspector.moduleSetting("showHTMLComments");
     this._showHTMLCommentsSetting.addChangeListener(this._onShowHTMLCommentsChange.bind(this));
@@ skipping 1704 matching lines @@
             if (node) {
                 this.treeOutline._selectedDOMNode = node;
                 this.treeOutline._selectedNodeChanged();
             }
         }
         return true;
     },
 
     __proto__: TreeElement.prototype
 };