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);
 
-port.on("request.websocket", (msg, sender) =>
+if ("WEBSOCKET" in chrome.webRequest.ResourceType)

[Sebastian Noack, 2017/03/27 12:13:36]

It seems this check should follow the same logic as the check in lib/csp.js:

  if (!("WEBSOCKET" in chrome.webRequest.ResourceType))

Otherwise, it seems, we redundantly process the WebSocket connections reported
by the WebSocket wrapper workaround when WebSockets are already handled by the
webRequest API, and vice-versa if WebSockets cannot be blocked by the webRequest
API (on Chrome <58) the WebSocket wrapper we rely on never gets a response.

[Jon Sonesen, 2017/03/27 12:35:23]

Yeah, I see that was an oversight. For some reason I had that logic inverted
here thinking we still wanted to wrap websocket connections even if websocket
support exists and csp injection is disabled. Sorry.

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