Issue 1280 - Update v8, the second part

src/JsContext.h

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2014 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/>.
  */
 
 #ifndef ADBLOCK_PLUS_JS_CONTEXT_H
 #define ADBLOCK_PLUS_JS_CONTEXT_H
 
 #include <v8.h>
 #include <AdblockPlus/JsEngine.h>
 
 namespace AdblockPlus
 {
-  class JsContext
+  class JsContext final
   {
   public:
-    JsContext(const JsEnginePtr jsEngine);
-    virtual ~JsContext() {};
-
+    JsContext(JsEngine& jsEngine);
   private:
     const v8::Locker locker;
+    // It sets current isolate and v8 stuff into thread local storage.
+    // Since we use it from different threads, it's required for the proper work.
+    const v8::Isolate::Scope isolateScope;
     const v8::HandleScope handleScope;
     const v8::Context::Scope contextScope;
   };
 }
 
 #endif