Issue #4688, #3595 - Web request use scheduled threads; unit tests terminate

src/WebRequestJsObject.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
@@ skipping 72 matching lines @@
   private:
     AdblockPlus::JsEnginePtr jsEngine;
     std::string url;
     AdblockPlus::HeaderList headers;
     AdblockPlus::JsValuePtr callback;
   };
 
   v8::Handle<v8::Value> GETCallback(const v8::Arguments& arguments)
   {
     std::shared_ptr<WebRequestTask> thread;
+    AdblockPlus::JsEnginePtr jsEngine;
     try
     {
-      AdblockPlus::JsEnginePtr jsEngine = AdblockPlus::JsEngine::FromArguments(arguments);
+      jsEngine = AdblockPlus::JsEngine::FromArguments(arguments);
       AdblockPlus::JsValueList converted = jsEngine->ConvertArguments(arguments);
       if (converted.size() != 3u)
         throw std::runtime_error("GET requires exactly 3 arguments");
       thread = std::make_shared<WebRequestTask>(jsEngine, converted);
     }
     catch (const std::exception& e)
     {
       using AdblockPlus::Utils::ToV8String;
       v8::Isolate* isolate = arguments.GetIsolate();
       return v8::ThrowException(ToV8String(isolate, e.what()));
     }
-    StartImmediatelyInSingleUseDetachedThread(AdblockPlus::MakeHeapFunction(thread));
+    jsEngine->Schedule(AdblockPlus::MakeHeapFunction(thread), AdblockPlus::ImmediateSingleUseThread);
     return v8::Undefined();
   }
 }
 
 AdblockPlus::JsValuePtr AdblockPlus::WebRequestJsObject::Setup(
     AdblockPlus::JsEnginePtr jsEngine, AdblockPlus::JsValuePtr obj)
 {
   obj->SetProperty("GET", jsEngine->NewCallback(::GETCallback));
   return obj;
 }