Issue 5450 - don't expose std::shared_ptr<FilterEngine>

include/AdblockPlus/Platform.h

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 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 63 matching lines @@
     {
       LogSystemPtr logSystem;
       TimerPtr timer;
       WebRequestPtr webRequest;
       FileSystemPtr fileSystem;
     };
 
     /**
      * Callback type invoked when FilterEngine is created.
      */
-    typedef std::function<void(const FilterEnginePtr&)> OnFilterEngineCreatedCallback;
+    typedef std::function<void(const FilterEngine&)> OnFilterEngineCreatedCallback;
 
     /**
      * Platform constructor.
      *
      * When a parameter value is nullptr the corresponding default
      * implementation is chosen.
      */
     explicit Platform(CreationParameters&& creationParameters = CreationParameters());
     ~Platform();
 
@@ skipping 20 matching lines @@
      */
     void CreateFilterEngineAsync(const FilterEngine::CreationParameters& parameters = FilterEngine::CreationParameters(),
       const OnFilterEngineCreatedCallback& onCreated = OnFilterEngineCreatedCallback());
 
     /**
      * Synchronous equivalent of `CreateFilterEngineAsync`.
      * Internally it blocks and waits for finishing of certain asynchronous
      * operations, please ensure that provided implementation does not lead to
      * a dead lock.
      */
-    FilterEnginePtr GetFilterEngine();
+    FilterEngine& GetFilterEngine();
 
     /**
     * @return The asynchronous ITimer implementation.
      */
     ITimer& GetTimer();
 
     /**
      * @return The asynchronous IFileSystem implementation.
      */
     IFileSystem& GetFileSystem();
@@ skipping 14 matching lines @@
     FileSystemPtr fileSystem;
     WebRequestPtr webRequest;
     // used for creation and deletion of modules.
     std::mutex modulesMutex;
     std::shared_ptr<JsEngine> jsEngine;
     std::shared_future<FilterEnginePtr> filterEngine;
   };
 }
 
 #endif // ADBLOCK_PLUS_PLATFORM_H