[DevTools] Do not inherit ObjectPopoverHelper from PopoverHelper.

third_party/WebKit/Source/devtools/front_end/network/NetworkLogViewColumns.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.
 /**
  * @unrestricted
  */
 Network.NetworkLogViewColumns = class {
   /**
    * @param {!Network.NetworkLogView} networkLogView
    * @param {!Network.NetworkTransferTimeCalculator} timeCalculator
@@ skipping 520 matching lines @@
       return;
     var anchor = element.enclosingNodeOrSelfWithClass('network-script-initiated');
     if (anchor && anchor.request) {
       var initiator = /** @type {!SDK.NetworkRequest} */ (anchor.request).initiator();
       if (initiator && initiator.stack)
         return anchor;
     }
   }
 
   /**
-   * @param {!Element} anchor
+   * @param {!Element|!AnchorBox} anchor
    * @param {!UI.GlassPane} popover
    * @return {!Promise<boolean>}
    */
   _showPopover(anchor, popover) {
     var request = /** @type {!SDK.NetworkRequest} */ (anchor.request);
     var initiator = /** @type {!Protocol.Network.Initiator} */ (request.initiator());
     var content = Components.DOMPresentationUtils.buildStackTracePreviewContents(
         request.target(), this._popupLinkifier, initiator.stack);
     popover.contentElement.appendChild(content);
     return Promise.resolve(true);
@@ skipping 255 matching lines @@
 /**
  * @enum {string}
  */
 Network.NetworkLogViewColumns.WaterfallSortIds = {
   StartTime: 'startTime',
   ResponseTime: 'responseReceivedTime',
   EndTime: 'endTime',
   Duration: 'duration',
   Latency: 'latency'
 };