Issue 4577 - Remove Safari support

include.preload.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 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 327 matching lines @@
 function runInPageContext(fn, arg)
 {
   var 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);
 }
 
-// Neither Chrome[1] nor Safari allow us to intercept WebSockets, and therefore
+// 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.
 // [1] - https://bugs.chromium.org/p/chromium/issues/detail?id=129353
 function wrapWebSocket()
 {
-  if (typeof WebSocket == "undefined")
-    return;
-
   var eventName = "abpws-" + Math.random().toString(36).substr(2);
 
   document.addEventListener(eventName, function(event)
   {
     ext.backgroundPage.sendMessage({
       type: "request.websocket",
       url: event.detail.url
     }, function (block)
     {
       document.dispatchEvent(
@@ skipping 267 matching lines @@
     checkCollapse(event.target);
   }, true);
 
   document.addEventListener("load", function(event)
   {
     var element = event.target;
     if (/^i?frame$/.test(element.localName))
       checkCollapse(element);
   }, true);
 }