Template out V8 and prepare for other JS engine implementations

include/AdblockPlus/Platform.h

 /*
  * 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 13 matching lines @@
 #include "IWebRequest.h"
 #include "AppInfo.h"
 #include "Scheduler.h"
 #include "FilterEngine.h"
 #include <mutex>
 #include <future>
 
 namespace AdblockPlus
 {
   struct IV8IsolateProvider;
-  class JsEngine;
+
+  template <class T> class JsEngineTemplate;
+#ifndef JSENGINEIMPL
+#define JSENGINEIMPL JsEngineTemplate<JsEngineNamespaceImpl>
+#endif // !JSENGINEIMPL
+  typedef JSENGINEIMPL JsEngine;
 
   /**
    * AdblockPlus platform is the main component providing access to other
    * modules.
    *
    * It manages the functionality modules, e.g. JsEngine and FilterEngine as
    * well as allows to correctly work with asynchronous functionality.
    */
   class Platform
   {
@@ skipping 35 matching lines @@
      * @param appInfo Information about the app, 
      * @param isolate A provider of v8::Isolate, if the value is nullptr then
      *        a default implementation is used.
      */
     void SetUpJsEngine(const AppInfo& appInfo = AppInfo(), std::unique_ptr<IV8IsolateProvider> isolate = nullptr);
 
     /**
      * Retrieves the `JsEngine` instance. It calls SetUpJsEngine if JsEngine is
      * not initialized yet.
      */
-    JsEngine& GetJsEngine();
+    JsEngineTemplate<JsEngineNamespaceImpl>& GetJsEngine();
 
     /**
      * Ensures that FilterEngine is constructed. Only the first call is effective.
      *
      * @param parameters optional creation parameters.
      * @param onCreated A callback which is called when FilterEngine is ready
      *        for use.
      */
     void CreateFilterEngineAsync(const FilterEngine::CreationParameters& parameters = FilterEngine::CreationParameters(),
       const OnFilterEngineCreatedCallback& onCreated = OnFilterEngineCreatedCallback());
@@ skipping 71 matching lines @@
      * when a corresponding field is nullptr and with a default Scheduler.
      */
     std::unique_ptr<Platform> CreatePlatform();
   private:
     std::shared_ptr<Scheduler> asyncExecutor;
     Scheduler defaultScheduler;
   };
 }
 
 #endif // ADBLOCK_PLUS_PLATFORM_H