[DevTools] Do not inherit ObjectPopoverHelper from PopoverHelper.

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 554 matching lines @@
           offsetHeight: this.offsetHeight,
           naturalWidth: this.naturalWidth,
           naturalHeight: this.naturalHeight,
           currentSrc: this.currentSrc
         };
       }
     }
   }
 
   /**
-   * @param {!Element} link
+   * @param {!Element|!AnchorBox} link
    * @param {!UI.GlassPane} popover
    * @return {!Promise<boolean>}
    */
   _showPopover(link, popover) {
     var fulfill;
     var promise = new Promise(x => fulfill = x);
     var listItem = link.enclosingNodeOrSelfWithNodeName('li');
     var node = /** @type {!Elements.ElementsTreeElement} */ (listItem.treeElement).node();
     this._loadDimensionsForNode(
         node, Components.DOMPresentationUtils.buildImagePreviewContents.bind(
@@ skipping 1107 matching lines @@
      */
     function resolved(node) {
       if (node) {
         this.treeOutline._selectedDOMNode = node;
         this.treeOutline._selectedNodeChanged();
       }
     }
     return true;
   }
 };