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

third_party/WebKit/Source/devtools/front_end/network/NetworkTimelineColumn.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.VBox}
  * @param {number} rowHeight
  * @param {number} headerHeight
  * @param {!WebInspector.NetworkTransferTimeCalculator} calculator
@@ skipping 12 matching lines @@
     this._leftPadding = 5;
     /** @const */
     this._rightPadding = 5;
     /** @const */
     this._fontSize = 10;
 
     this._rowHeight = rowHeight;
     this._headerHeight = headerHeight;
     this._calculator = calculator;
 
-    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(300, 300);
 
     this._vScrollElement = this.contentElement.createChild("div", "network-timeline-v-scroll");
     this._vScrollElement.addEventListener("scroll", this._onScroll.bind(this), { passive: true });
     this._vScrollElement.addEventListener("mousewheel", this._onMouseWheel.bind(this), { passive: true });
     this._vScrollContent = this._vScrollElement.createChild("div", "network-timeline-v-scroll-content");
 
     this.element.addEventListener("mousewheel", this._onMouseWheel.bind(this), { passive: true });
     this.element.addEventListener("mousemove", this._onMouseMove.bind(this), true);
     this.element.addEventListener("mouseleave", this.setHoveredRequest.bind(this, null), true);
@@ skipping 595 matching lines @@
             color = this._rowNavigationRequestColor;
 
         context.fillStyle = color;
         context.rect(0, y, this._offsetWidth, this._rowHeight);
         context.fill();
         context.restore();
     },
 
     __proto__: WebInspector.VBox.prototype
 };