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

third_party/WebKit/Source/devtools/front_end/ui_lazy/TimelineOverviewPane.js

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 34 matching lines @@
     this._cursorElement = this._overviewGrid.element.createChild("div", "overview-grid-cursor-position");
     this._cursorArea.addEventListener("mousemove", this._onMouseMove.bind(this), true);
     this._cursorArea.addEventListener("mouseleave", this._hideCursor.bind(this), true);
 
     this._overviewGrid.setResizeEnabled(false);
     this._overviewGrid.addEventListener(WebInspector.OverviewGrid.Events.WindowChanged, this._onWindowChanged, this);
     this._overviewGrid.addEventListener(WebInspector.OverviewGrid.Events.Click, this._onClick, this);
     this._overviewControls = [];
     this._markers = new Map();
 
-    this._popoverHelper = new WebInspector.PopoverHelper(this._cursorArea, this._getPopoverAnchor.bind(this), this._showPopover.bind(this), this._onHidePopover.bind(this));
+    this._popoverHelper = new WebInspector.PopoverHelper(this._cursorArea);
+    this._popoverHelper.initializeCallbacks(this._getPopoverAnchor.bind(this), this._showPopover.bind(this), this._onHidePopover.bind(this));
     this._popoverHelper.setTimeout(0);
 
     this._updateThrottler = new WebInspector.Throttler(100);
 
     this._cursorEnabled = false;
     this._cursorPosition = 0;
     this._lastWidth = 0;
 };
 
 /** @enum {symbol} */
@@ skipping 567 matching lines @@
     },
 
     resetCanvas: function()
     {
         this._canvas.width = this.element.clientWidth * window.devicePixelRatio;
         this._canvas.height = this.element.clientHeight * window.devicePixelRatio;
     },
 
     __proto__: WebInspector.VBox.prototype
 };