Issue 6645 - Collapse elements through user style sheets if possible

include.preload.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 140 matching lines @@
   // setting the style="..." attribute.
   if (element.localName == "video" || element.localName == "audio")
   {
     for (let child of element.children)
     {
       if (child.localName == "source" || child.localName == "track")
         return null;
     }
   }
 
-  let selector = element.localName;
-  let hasSrc = false;
+  let selector = "";
   for (let attr of ["src", "srcset"])
   {
     let value = element.getAttribute(attr);
     if (value && attr in element)
-    {
       selector += "[" + attr + "=" + CSS.escape(value) + "]";
-      hasSrc = true;
-    }
-  }
-
-  return hasSrc ? selector : null;
+  }
+
+  return selector ? element.localName + selector : null;
 }
 
 function hideElement(element)
 {
   function doHide()
   {
     let propertyName = "display";
     let propertyValue = "none";
     if (element.localName == "frame")
     {
@@ skipping 425 matching lines @@
     let element = event.target;
     if (/^i?frame$/.test(element.localName))
       checkCollapse(element);
   }, true);
 }
 
 window.checkCollapse = checkCollapse;
 window.elemhide = elemhide;
 window.typeMap = typeMap;
 window.getURLsFromElement = getURLsFromElement;