Issue 5013 - Use const JsValue and pass reference where applicable

src/JsEngine.cpp

 /*
  * 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 168 matching lines @@
   std::lock_guard<std::mutex> lock(eventCallbacksMutex);
   eventCallbacks[eventName] = callback;
 }
 
 void AdblockPlus::JsEngine::RemoveEventCallback(const std::string& eventName)
 {
   std::lock_guard<std::mutex> lock(eventCallbacksMutex);
   eventCallbacks.erase(eventName);
 }
 
-void AdblockPlus::JsEngine::TriggerEvent(const std::string& eventName, const AdblockPlus::JsValueList& params)
+void AdblockPlus::JsEngine::TriggerEvent(const std::string& eventName, const AdblockPlus::JsConstValueList& params)
 {
   EventCallback callback;
   {
     std::lock_guard<std::mutex> lock(eventCallbacksMutex);
     auto it = eventCallbacks.find(eventName);
     if (it == eventCallbacks.end())
       return;
     callback = it->second;
   }
   callback(params);
@@ skipping 49 matching lines @@
   const v8::Local<const v8::External> external =
       v8::Local<const v8::External>::Cast(arguments.Data());
   std::weak_ptr<JsEngine>* data =
       static_cast<std::weak_ptr<JsEngine>*>(external->Value());
   JsEnginePtr result = data->lock();
   if (!result)
     throw std::runtime_error("Oops, our JsEngine is gone, how did that happen?");
   return result;
 }
 
-AdblockPlus::JsValueList AdblockPlus::JsEngine::ConvertArguments(const v8::Arguments& arguments)
+AdblockPlus::JsConstValueList AdblockPlus::JsEngine::ConvertArguments(const v8::Arguments& arguments)
 {
   const JsContext context(shared_from_this());
-  JsValueList list;
+  JsConstValueList list;
   for (int i = 0; i < arguments.Length(); i++)
     list.push_back(JsValuePtr(new JsValue(shared_from_this(), arguments[i])));
   return list;
 }
 
 AdblockPlus::FileSystemPtr AdblockPlus::JsEngine::GetFileSystem() const
 {
   return fileSystem;
 }
 
@@ skipping 53 matching lines @@
 
 
 void AdblockPlus::JsEngine::SetGlobalProperty(const std::string& name,
                                               const AdblockPlus::JsValuePtr& value)
 {
   auto global = GetGlobalObject();
   if (!global)
     throw std::runtime_error("Global object cannot be null");
   global->SetProperty(name, value);
 }