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

lib/content/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 587 matching lines @@
   return patterns.some(pattern => pattern.maybeDependsOnAttributes);
 }
 
 function shouldObserveCharacterData(patterns)
 {
   return patterns.some(pattern => pattern.dependsOnCharacterData);
 }
 
 class ElemHideEmulation
 {
-  constructor(addSelectorsFunc, hideElemsFunc)
-  {
-    // Note: The first parameter to this constructor was previously used for
-    // injecting style sheets into the document for :-abp-properties() but this
-    // code has since moved on to use inline styles for all types of emulation
-    // filters (#6610). Nevertheless, there is a plan to go back to using style
-    // sheets on platforms that support the tabs.removeCSS API (#6504); hence
-    // this first parameter remains for now.
-
+  constructor(hideElemsFunc)
+  {
     this._filteringInProgress = false;
     this._lastInvocation = -MIN_INVOCATION_INTERVAL;
     this._scheduledProcessing = null;
 
     this.document = document;
     this.hideElemsFunc = hideElemsFunc;
     this.observer = new MutationObserver(this.observe.bind(this));
   }
 
   isSameOrigin(stylesheet)
@@ skipping 345 matching lines @@
           characterData: shouldObserveCharacterData(this.patterns),
           subtree: true
         }
       );
       this.document.addEventListener("load", this.onLoad.bind(this), true);
     }
   }
 }
 
 exports.ElemHideEmulation = ElemHideEmulation;