Issue 5013 - Use const JsValue and pass reference where applicable

include/AdblockPlus/JsEngine.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 75 matching lines @@
    */
   class JsEngine : public std::enable_shared_from_this<JsEngine>
   {
     friend class JsValue;
     friend class JsContext;
 
   public:
     /**
      * Event callback function.
      */
-    typedef std::function<void(const JsValueList& params)> EventCallback;
+    typedef std::function<void(const JsConstValueList& params)> EventCallback;
 
     /**
     * Callback function returning false when current connection is not allowed
     * e.g. because it is a metered connection.
     */
     typedef std::function<bool()> IsConnectionAllowedCallback;
 
     /**
      * Maps events to callback functions.
      */
@@ skipping 23 matching lines @@
      * Removes the callback function for an event.
      * @param eventName Event name.
      */
     void RemoveEventCallback(const std::string& eventName);
 
     /**
      * Triggers an event.
      * @param eventName Event name.
      * @param params Event parameters.
      */
-    void TriggerEvent(const std::string& eventName, const JsValueList& params);
+    void TriggerEvent(const std::string& eventName, const JsConstValueList& params);
 
     /**
      * Evaluates a JavaScript expression.
      * @param source JavaScript expression to evaluate.
      * @param filename Optional file name for the expression, used in error
      *        messages.
      * @return Result of the evaluated expression.
      */
     JsValuePtr Evaluate(const std::string& source,
         const std::string& filename = "");
@@ skipping 57 matching lines @@
      * Private functionality required to implement timers.
      * @param arguments `v8::Arguments` is the arguments received in C++
      * callback associated for global setTimeout method.
      */
     static void ScheduleTimer(const v8::Arguments& arguments);
 
     /**
      * Converts v8 arguments to `JsValue` objects.
      * @param arguments `v8::Arguments` object containing the arguments to
      *        convert.
-     * @return List of arguments converted to `JsValue` objects.
+     * @return List of arguments converted to `const JsValue` objects.
      */
-    JsValueList ConvertArguments(const v8::Arguments& arguments);
+    JsConstValueList ConvertArguments(const v8::Arguments& arguments);
 
     /**
      * @see `SetFileSystem()`.
      */
     FileSystemPtr GetFileSystem() const;
 
     /**
      * Sets the `FileSystem` implementation used for all file I/O.
      * Setting this is optional, the engine will use a `DefaultFileSystem`
      * instance by default, which might be sufficient.
@@ skipping 80 matching lines @@
     EventMap eventCallbacks;
     std::mutex eventCallbacksMutex;
     mutable std::mutex isConnectionAllowedMutex;
     IsConnectionAllowedCallback isConnectionAllowed;
     TimerTasks timerTasks;
     TimerPtr timer;
   };
 }
 
 #endif