Issue 6997 - Use createStyleSheet implementation from core

lib/contentFiltering.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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 /** @module contentFiltering */
 
 "use strict";
 
 const {RegExpFilter} = require("../adblockpluscore/lib/filterClasses");
-const {ElemHide} = require("../adblockpluscore/lib/elemHide");
+const {ElemHide, createStyleSheet} = require("../adblockpluscore/lib/elemHide");
 const {ElemHideEmulation} = require("../adblockpluscore/lib/elemHideEmulation");
 const {filterNotifier} = require("../adblockpluscore/lib/filterNotifier");
 const {Snippets, compileScript} = require("../adblockpluscore/lib/snippets");
 const {checkWhitelisted} = require("./whitelisting");
 const {extractHostFromFrame} = require("./url");
 const {port} = require("./messaging");
 const {HitLogger, logRequest} = require("./hitLogger");
 const info = require("info");
 
 // Chromium's support for tabs.removeCSS is still a work in progress and the
 // API is likely to be different from Firefox's; for now we just don't use it
 // at all, even if it's available.
 // See https://crbug.com/608854
 const styleSheetRemovalSupported = info.platform == "gecko";
 
 const selectorGroupSize = 1024;
 
 let userStyleSheetsSupported = true;
 
 let snippetsLibrarySource = "";
 let executableCode = new Map();
 
-function* splitSelectors(selectors)
-{
-  // Chromium's Blink engine supports only up to 8,192 simple selectors, and
-  // even fewer compound selectors, in a rule. The exact number of selectors
-  // that would work depends on their sizes (e.g. "#foo .bar" has a size of 2).
-  // Since we don't know the sizes of the selectors here, we simply split them
-  // into groups of 1,024, based on the reasonable assumption that the average
-  // selector won't have a size greater than 8. The alternative would be to
-  // calculate the sizes of the selectors and divide them up accordingly, but
-  // this approach is more efficient and has worked well in practice. In theory
-  // this could still lead to some selectors not working on Chromium, but it is
-  // highly unlikely.
-  // See issue #6298 and https://crbug.com/804179
-  for (let i = 0; i < selectors.length; i += selectorGroupSize)
-    yield selectors.slice(i, i + selectorGroupSize);
-}
-
-function* createRules(selectors)
-{
-  for (let selectorGroup of splitSelectors(selectors))
-    yield selectorGroup.join(", ") + " {display: none !important;}";
-}
-
-function createStyleSheet(selectors)
-{
-  return Array.from(createRules(selectors)).join("\n");
-}
-
 function addStyleSheet(tabId, frameId, styleSheet)
 {
   try
   {
     let promise = browser.tabs.insertCSS(tabId, {
       code: styleSheet,
       cssOrigin: "user",
       frameId,
       matchAboutBlank: true,
       runAt: "document_start"
@@ skipping 209 matching lines @@
   updateFrameStyles(sender.page.id, sender.frame.id, message.selectors,
                     message.groupName, message.appendOnly);
 });
 
 fetch(browser.extension.getURL("/snippets.js"), {cache: "no-cache"})
 .then(response => response.ok ? response.text() : "")
 .then(text =>
 {
   snippetsLibrarySource = text;
 });