Issue 1602 - Use ES6 generators instead of legacy generators

lib/io.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 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 51 matching lines @@
     } catch (e) {}
 
     return null;
   },
 
   /**
    * Reads strings from a file asynchronously, calls listener.process() with
    * each line read and with a null parameter once the read operation is done.
    * The callback will be called when the operation is done.
    */
-  readFromFile: function(/**nsIFile*/ file, /**Object*/ listener, /**Function*/ callback)
+  readFromFile: function*(/**nsIFile*/ file, /**Object*/ listener, /**Function*/ callback)
   {
     try
     {
       let processing = false;
       let buffer = "";
       let loaded = false;
       let error = null;
 
       let onProgress = function(data)
       {
@@ skipping 104 matching lines @@
     catch (e)
     {
       callback(e);
     }
   },
 
   /**
    * Writes string data to a file in UTF-8 format asynchronously. The callback
    * will be called when the write operation is done.
    */
-  writeToFile: function(/**nsIFile*/ file, /**Iterator*/ data, /**Function*/ callback)
+  writeToFile: function*(/**nsIFile*/ file, /**Iterator*/ data, /**Function*/ callback)
   {
     try
     {
       let encoder = new TextEncoder();
 
       Task.spawn(function()
       {
         // This mimics OS.File.writeAtomic() but writes in chunks.
         let tmpPath = file.path + ".tmp";
         let f = yield OS.File.open(tmpPath, {write: true, truncate: true});
@@ skipping 115 matching lines @@
         else
           callback(e);
       });
     }
     catch(e)
     {
       callback(e);
     }
   }
 }