Issue #4692, #3595 - Stop sleeping in the implementation of `SetTimeout`

src/Scheduler.cpp

 /*
  * 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include "Scheduler.h"
 #include <thread>
-using namespace AdblockPlus;
-
-namespace
-{
-  void SingleUseThreadMain(std::function<void()> task)
-  {
-    task();
-  }
-}
-
-void StartImmediatelyInSingleUseDetachedThread(std::function<void()> task)
-{
-  if (!task)
-  {
-    return;
-  }
-  auto th = std::thread(SingleUseThreadMain, task);
-  th.detach();
-}
 
 OperationRunner::OperationRunner()
   : isRunning(true)
 {
   th = std::thread([this]() { ThreadMain(); });
   /*
    * Note that we don't need to wait for our thread to start running
    *   before we consider the object fully constructed.
    * Because of how the `wait()` statement in `ThreadMain` is written,
    *   any operation arriving before the thread begins will be
@@ skipping 59 matching lines @@
   th = std::move(std::thread(f));
 }
 
 void SingleUseWorker::Join()
 {
   if (th.joinable())
   {
     th.join();
   }
 }