Noissue - Cleanup. Remove last remnants of old thread code.

test/Notification.cpp

 /*
  * 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 108 matching lines @@
   };
 }
 
 TEST_F(NotificationTest, NoNotifications)
 {
   EXPECT_FALSE(PeekNotification());
 }
 
 TEST_F(NotificationMockWebRequestTest, DISABLED_SingleNotification)
 {
-  AdblockPlus::Sleep(5000/*msec*/); // it's a hack
+  std::this_thread::sleep_for(std::chrono::milliseconds(5000)); // it's a hack
   EXPECT_TRUE(isNotificationCallbackCalled);
 }
 
 TEST_F(NotificationTest, AddNotification)
 {
   AddNotification("{"
       "type: 'critical',"
       "title: 'testTitle',"
       "message: 'testMessage',"
     "}");
@@ skipping 48 matching lines @@
 TEST_F(NotificationTest, Links)
 {
   AddNotification("{ id: 'id', links: ['link1', 'link2'] }");
   auto notification = PeekNotification();
   ASSERT_TRUE(notification);
   std::vector<std::string> notificationLinks = notification->GetLinks();
   ASSERT_EQ(2u, notificationLinks.size());
   EXPECT_EQ("link1", notificationLinks[0]);
   EXPECT_EQ("link2", notificationLinks[1]);
 }