Issue 6504 - Remove element hiding emulation code related to style sheets

test/browser/elemHideEmulation.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 135 matching lines @@
   insertStyleRule("#" + element.id + " " + styleBlock);
   return element;
 }
 
 // Create a new ElemHideEmulation instance with @selectors.
 function applyElemHideEmulation(selectors)
 {
   return Promise.resolve().then(() =>
   {
     let elemHideEmulation = new ElemHideEmulation(
-      newSelectors =>
-      {
-        if (!newSelectors.length)
-          return;
-        let selector = newSelectors.join(", ");
-        insertStyleRule(selector + "{display: none !important;}");
-      },
       elems =>
       {
         for (let elem of elems)
           elem.style.display = "none";
       }
     );
 
     elemHideEmulation.document = testDocument;
     elemHideEmulation.MIN_INVOCATION_INTERVAL = REFRESH_INTERVAL / 2;
     elemHideEmulation.apply(selectors.map(
@@ skipping 868 matching lines @@
     for (let element of [...testDocument.getElementsByTagName("div"),
                          ...testDocument.getElementsByTagName("p")])
     {
       if (element.id == "n2" || element.id == "n2_3")
         expectProcessed(test, element, element.id);
       else
         expectNotProcessed(test, element, element.id);
     }
   }).catch(unexpectedError.bind(test)).then(() => test.done());
 };