[DevTools] Do not inherit ObjectPopoverHelper from PopoverHelper.

third_party/WebKit/Source/devtools/front_end/ui/Popover.js

 /*
  * Copyright (C) 2009 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 29 matching lines @@
     this._disableOnClick = !!disableOnClick;
     this._hasPadding = false;
     panelElement.addEventListener('mousedown', this._mouseDown.bind(this), false);
     panelElement.addEventListener('mousemove', this._mouseMove.bind(this), false);
     panelElement.addEventListener('mouseout', this._mouseOut.bind(this), false);
     this.setTimeout(1000, 500);
   }
 
   /**
    * @param {function(!Element, !Event):(!Element|!AnchorBox|undefined)} getAnchor
-   * @param {function(!Element, !UI.GlassPane):!Promise<boolean>} showPopover
+   * @param {function((!Element|!AnchorBox), !UI.GlassPane):!Promise<boolean>} showPopover
    * @param {function()=} onHide
    */
   initializeCallbacks(getAnchor, showPopover, onHide) {
     this._getAnchor = getAnchor;
     this._showPopover = showPopover;
     this._onHide = onHide;
   }
 
   /**
    * @param {number} timeout
@@ skipping 152 matching lines @@
     if (this._hidePopoverTimer) {
       clearTimeout(this._hidePopoverTimer);
       delete this._hidePopoverTimer;
 
       // We know that we reached the popup, but we might have moved over other elements.
       // Discard pending command.
       this._resetHoverTimer();
     }
   }
 };