Issue 4864 - Start using ESLint for adblockpluschrome

include.preload.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 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 319 matching lines @@
 function runInPageContext(fn, arg)
 {
   let script = document.createElement("script");
   script.type = "application/javascript";
   script.async = false;
   script.textContent = "(" + fn + ")(" + JSON.stringify(arg) + ");";
   document.documentElement.appendChild(script);
   document.documentElement.removeChild(script);
 }
 
-// Chrome doesn't allow us to intercept WebSockets[1], and therefore
-// some ad networks are misusing them as a way to serve adverts and circumvent
-// us. As a workaround we wrap WebSocket, preventing blocked WebSocket
-// connections from being opened.
+// Before Chrome 58 the webRequest API didn't allow us to intercept
+// WebSockets[1], and therefore some ad networks are misusing them as a way to
+// serve adverts and circumvent us. As a workaround we wrap WebSocket,
+// preventing blocked WebSocket connections from being opened.
 // [1] - https://bugs.chromium.org/p/chromium/issues/detail?id=129353
 function wrapWebSocket()
 {
   let randomEventName = "abpws-" + Math.random().toString(36).substr(2);
 
   document.addEventListener(randomEventName, event =>
   {
     ext.backgroundPage.sendMessage({
       type: "request.websocket",
       url: event.detail.url
@@ skipping 221 matching lines @@
     checkCollapse(event.target);
   }, true);
 
   document.addEventListener("load", event =>
   {
     let element = event.target;
     if (/^i?frame$/.test(element.localName))
       checkCollapse(element);
   }, true);
 }