Issue #3593 - Make isolate a fully internal member of the engine

include/AdblockPlus/JsEngine.h

Index: include/AdblockPlus/JsEngine.h
===================================================================
--- a/include/AdblockPlus/JsEngine.h
+++ b/include/AdblockPlus/JsEngine.h
@@ -50,31 +50,6 @@
   typedef std::shared_ptr<JsEngine> JsEnginePtr;
 
   /**
-   * Scope based isolate manager. Creates a new isolate instance on
-   * constructing and disposes it on destructing.
-   */
-  class ScopedV8Isolate
-  {
-  public:
-    ScopedV8Isolate();
-    ~ScopedV8Isolate();
-    v8::Isolate* Get()
-    {
-      return isolate;
-    }
-  private:
-    ScopedV8Isolate(const ScopedV8Isolate&);
-    ScopedV8Isolate& operator=(const ScopedV8Isolate&);
-
-    v8::Isolate* isolate;
-  };
-
-  /**
-   * Shared smart pointer to ScopedV8Isolate instance;
-   */
-  typedef std::shared_ptr<ScopedV8Isolate> ScopedV8IsolatePtr;
-
-  /**
    * JavaScript engine used by `FilterEngine`, wraps v8.
    */
   class JsEngine : public std::enable_shared_from_this<JsEngine>
@@ -97,7 +72,7 @@
      *        as a temporary hack for tests, it will go away. Issue #3593.
      * @return New `JsEngine` instance.
      */
-    static JsEnginePtr New(const AppInfo& appInfo = AppInfo(), const ScopedV8IsolatePtr& isolate = ScopedV8IsolatePtr(new ScopedV8Isolate()));
+    static JsEnginePtr New(const AppInfo& appInfo = AppInfo());
 
     /**
      * Registers the callback function for an event.
@@ -243,13 +218,22 @@
     /**
      * Returns a pointer to associated v8::Isolate.
      */
-    v8::Isolate* GetIsolate()
+    v8::Isolate* GetIsolate() const
     {
-      return isolate->Get();
+      return isolate;
     }
 
+    /// Ordinary destructor
+    ~JsEngine();
+
   protected:
-    explicit JsEngine(const ScopedV8IsolatePtr& isolate);
+    /**
+     * Non-public constructor enforces factory use.
+     *
+     * @param isolate
+     *   v8 isolate obtained from its factory
+     */
+    explicit JsEngine(v8::Isolate* isolate);
 
     /**
      * Retrieve the global object as a JsValuePtr
@@ -259,9 +243,12 @@
      */
     JsValuePtr GetGlobalObject();
 
-    /// Isolate must be disposed only after disposing of all objects which are
-    /// using it.
-    ScopedV8IsolatePtr isolate;
+    /**
+     * Isolate member must be have life span that encompasses any other object
+     * that uses it. Thus it's declared first so that it is constructed first
+     * and destroyed last.
+     */
+    v8::Isolate* isolate;
 
     FileSystemPtr fileSystem;
     WebRequestPtr webRequest;