Issue 3890 - Fix "Downloading..." indication for subscriptions on the options page

background.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 269 matching lines @@
         errors: []
       };
     }
   };
 
   modules.synchronizer = {
     Synchronizer: {
       _downloading: false,
       execute: function(subscription, manual) 
       {
-        subscription.lastDownload = 0;

[Sebastian Noack, 2016/04/05 18:38:48]

This was wrong. The lastDownload property isn't reset by the core code when the
download starts. However, "subscription.downloading" is dispatched.

         modules.synchronizer.Synchronizer._downloading = true;
+        modules.filterNotifier.FilterNotifier.emit("subscription.downloading", subscription);

[kzar, 2016/04/06 08:53:37]

Nit: Mind breaking this long line at the comma?

[Sebastian Noack, 2016/04/06 09:13:00]

Done.

         setTimeout(function()
         {
           modules.synchronizer.Synchronizer._downloading = false;
           subscription.lastDownload = Date.now() / 1000;
         }, 500);
       },
       isExecuting: function(url)
       {
         return modules.synchronizer.Synchronizer._downloading;
       }
@@ skipping 177 matching lines @@
 
   if (params.safariContentBlocker)
   {
     global.safari = {
       extension: {
         setContentBlocker: function() {}
       }
     };
   }
 })(this);