Issue 1488 - Add pre-configurable preference to suppress first run page

lib/prefs.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 79 matching lines @@
 }
 
 function init()
 {
   let prefs = Object.keys(defaults);
   prefs.forEach(addPreference);
 
   let localLoaded = false;
   let managedLoaded = false;
 
-  let onProgress = function()

[kzar, 2015/04/08 13:55:45]

I found this function name a little confusing when trying to grok the code. How
about something like "watchIfLoaded"? (Or alternatively how about a comment
explaining the idea of the function?)

[Sebastian Noack, 2015/04/08 15:11:20]

Renamed it to checkLoaded, as well for the code in background.js. However, note
that the change there is only visible here due to rebasing. I have performed the
change in the respective patch which is under review as well.

+  let checkLoaded = function()
   {
     if (!localLoaded || !managedLoaded)
       return;
 
     ext.storage.onChanged.addListener(function(changes)
     {
       for (let key in changes)
       {
         let pref = keyToPref(key);
         if (pref && pref in defaults)
@@ skipping 38 matching lines @@
     },
 
     done: function()
     {
       ext.storage.get(prefs.map(prefToKey), function(items)
       {
         for (let key in items)
           overrides[keyToPref(key)] = items[key];
 
         localLoaded = true;
-        onProgress();
+        checkLoaded();
       });
     }
   });
 
   if (require("info").platform == "chromium" && "managed" in chrome.storage)
   {
     chrome.storage.managed.get(null, function(items)
     {
       for (let key in items)
         defaults[key] = items[key];
 
       managedLoaded = true;
-      onProgress();
+      checkLoaded();
     });
   }
   else
   {
     managedLoaded = true;
-    onProgress();
+    checkLoaded();
   }
 }
 
 init();