Template out V8 and prepare for other JS engine implementations

include/AdblockPlus/JsEngine.h

Index: include/AdblockPlus/JsEngine.h
===================================================================
--- a/include/AdblockPlus/JsEngine.h
+++ b/include/AdblockPlus/JsEngine.h
@@ -44,8 +44,8 @@
 
 namespace AdblockPlus
 {
-  class JsEngine;
   class Platform;
+  template <typename T> class JsEngineTemplate;
 
   /**
    * Shared smart pointer to a `JsEngine` instance.
@@ -67,20 +67,32 @@
     virtual v8::Isolate* Get() = 0;
   };
 
+  template <typename T>
+  struct JsWeakValuesList
+  {
+    ~JsWeakValuesList();
+    std::vector<T> values;
+  };
+  typedef std::list<JsWeakValuesList<v8::Global<v8::Value>>> JsWeakValuesLists;
+
+  /**
+  * An opaque structure representing ID of stored JsValueList.
+  */
+  class JsWeakValuesID
+  {
+    template <typename T> friend class JsEngineTemplate;
+    JsWeakValuesLists::const_iterator iterator;
+  };
+
+
   /**
    * JavaScript engine used by `FilterEngine`, wraps v8.
    */
-  class JsEngine : public std::enable_shared_from_this<JsEngine>
+  template <typename T> class JsEngineTemplate : public std::enable_shared_from_this<JsEngineTemplate<T>>
   {
-    friend class JsValue;
-    friend class JsContext;
+    template <typename T> friend class JsValueTemplate;
+    template <typename T> friend class JsContextTemplate;
 
-    struct JsWeakValuesList
-    {
-      ~JsWeakValuesList();
-      std::vector<v8::Global<v8::Value>> values;
-    };
-    typedef std::list<JsWeakValuesList> JsWeakValuesLists;
   public:
     /**
      * Event callback function.
@@ -93,15 +105,6 @@
     typedef std::map<std::string, EventCallback> EventMap;
 
     /**
-     * An opaque structure representing ID of stored JsValueList.
-     */
-    class JsWeakValuesID
-    {
-      friend class JsEngine;
-      JsWeakValuesLists::const_iterator iterator;
-    };
-
-    /**
      * Creates a new JavaScript engine instance.
      *
      * @param appInfo Information about the app.
@@ -186,7 +189,7 @@
      *        the current `JsEngine`.
      * @return New `JsValue` instance.
      */
-    JsValue NewCallback(const v8::FunctionCallback& callback);
+    JsValue NewCallback(const typename T::CallbackFunc& callback);
 
     /**
      * Returns a `JsEngine` instance contained in a `v8::FunctionCallbackInfo` object.
@@ -196,7 +199,7 @@
      *        instance.
      * @return `JsEngine` instance from `v8::FunctionCallbackInfo`.
      */
-    static JsEnginePtr FromArguments(const v8::FunctionCallbackInfo<v8::Value>& arguments);
+    static JsEnginePtr FromArguments(const typename T::CallbackFuncInfo& arguments);
 
     /**
      * Stores `JsValue`s in a way they don't keep a strong reference to
@@ -223,14 +226,14 @@
      * @param arguments `v8::FunctionCallbackInfo` is the arguments received in C++
      * callback associated for global setTimeout method.
      */
-    static void ScheduleTimer(const v8::FunctionCallbackInfo<v8::Value>& arguments);
+    static void ScheduleTimer(const typename T::CallbackFuncInfo& arguments);
 
     /*
      * Private functionality required to implement web requests.
      * @param arguments `v8::FunctionCallbackInfo` is the arguments received in C++
      * callback associated for global GET method.
      */
-    static void ScheduleWebRequest(const v8::FunctionCallbackInfo<v8::Value>& arguments);
+    static void ScheduleWebRequest(const typename T::CallbackFuncInfo& arguments);
 
     /**
      * Converts v8 arguments to `JsValue` objects.
@@ -238,7 +241,7 @@
      *        convert.
      * @return List of arguments converted to `const JsValue` objects.
      */
-    JsValueList ConvertArguments(const v8::FunctionCallbackInfo<v8::Value>& arguments);
+    JsValueList ConvertArguments(const typename T::CallbackFuncInfo& arguments);
 
     /**
      * Sets a global property that can be accessed by all the scripts.
@@ -250,7 +253,7 @@
     /**
      * Returns a pointer to associated v8::Isolate.
      */
-    v8::Isolate* GetIsolate()
+    typename T::Isolate* GetIsolate()
     {
       return isolate->Get();
     }
@@ -271,7 +274,7 @@
   private:
     void CallTimerTask(const JsWeakValuesID& timerParamsID);
 
-    explicit JsEngine(Platform& platform, std::unique_ptr<IV8IsolateProvider> isolate);
+    explicit JsEngineTemplate(Platform& platform, std::unique_ptr<IV8IsolateProvider> isolate);
 
     JsValue GetGlobalObject();
 
@@ -280,7 +283,7 @@
     /// using it.
     std::unique_ptr<IV8IsolateProvider> isolate;
 
-    std::unique_ptr<v8::Global<v8::Context>> context;
+    std::unique_ptr<typename T::GlobalContext> context;
     EventMap eventCallbacks;
     std::mutex eventCallbacksMutex;
     JsWeakValuesLists jsWeakValuesLists;