Issue 4580 - Replace ext.backgroundPage.sendMessage with runtime.sendMessage

ext/common.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
@@ skipping 49 matching lines @@
   if (!(Symbol.iterator in NodeList.prototype))
     NodeList.prototype[Symbol.iterator] = arrayIterator;
   if (!(Symbol.iterator in StyleSheetList.prototype))
     StyleSheetList.prototype[Symbol.iterator] = arrayIterator;
   if (!(Symbol.iterator in CSSRuleList.prototype))
     CSSRuleList.prototype[Symbol.iterator] = arrayIterator;
 
   /* Message passing */
 
   ext.onMessage = new ext._EventTarget();
-
-
-  /* Background page */
-
-  ext.backgroundPage = {
-    getWindow()
-    {
-      return chrome.extension.getBackgroundPage();
-    }
-  };
-
-
-  /* Utils */
-
-  ext.getURL = chrome.extension.getURL;
 }());