Issue 5027 - Use updated webRequest API for WebSocket blocking

lib/requestBlocker.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 134 matching lines @@
 
 FilterNotifier.on("subscription.added", onFilterChange);
 FilterNotifier.on("subscription.removed", onFilterChange);
 FilterNotifier.on("subscription.updated", onFilterChange);
 FilterNotifier.on("subscription.disabled", arg => onFilterChange(arg, true));
 FilterNotifier.on("filter.added", onFilterChange);
 FilterNotifier.on("filter.removed", onFilterChange);
 FilterNotifier.on("filter.disabled", arg => onFilterChange(arg, true));
 FilterNotifier.on("load", onFilterChange);
 
+// Before Chrome 58, the webRequest API didn't intercept WebSocket connections,
+// (see https://crbug.com/129353). Hence we patched the WebSocket object as a
+// workaround. WebSocket connections detected by this workaround are handled
+// below.
 if (!("WEBSOCKET" in chrome.webRequest.ResourceType))

[kzar, 2017/03/28 05:38:13]

Again please leave a comment here explaining that why this code is necessary for
versions of Chrome before 58. Ideally link the Chromium issue too.

That way when we increase the minimum Chrome version in the future it will be
obvious that we can remove this code.

[Jon Sonesen, 2017/03/28 13:03:14]

No problem

 {
   port.on("request.websocket", (msg, sender) =>
   {
     return ext.webRequest.onBeforeRequest._dispatch(
       new URL(msg.url),
       "WEBSOCKET",
       sender.page,
       sender.frame
     ).indexOf(false) != -1;
   });
 }