Issue 2541 - Suppress error on Opera when calling chrome.storage.managed.get()

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 265 matching lines @@
         localLoaded = true;
         checkLoaded();
       });
     }
   });
 
   if (require("info").platform == "chromium" && "managed" in chrome.storage)
   {
     chrome.storage.managed.get(null, function(items)
     {
+      // Opera doesn't support chrome.storage.managed, but instead simply
+      // removing the API, Opera sets chrome.runtime.lastError when using it.
+      // So we have to retrieve that error, to prevent it from showing up
+      // in the console.
+      chrome.runtime.lastError;
+
       for (let key in items)
         defaults[key] = items[key];
 
       managedLoaded = true;
       checkLoaded();
     });
   }
   else
   {
     managedLoaded = true;
     checkLoaded();
   }
 }
 
 init();