Issue 5013 - Make parameter const ref when applicable.

src/JsValue.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 189 matching lines @@
 std::string AdblockPlus::JsValue::GetClass() const
 {
   if (!IsObject())
     throw new std::runtime_error("Cannot get constructor of a non-object");
 
   const JsContext context(jsEngine);
   v8::Local<v8::Object> obj = v8::Local<v8::Object>::Cast(UnwrapValue());
   return Utils::FromV8String(obj->GetConstructorName());
 }
 
-JsValue JsValue::Call(const JsConstValueList& params, JsValuePtr thisPtr) const
+JsValue JsValue::Call(const JsConstValueList& params, const JsValuePtr& thisPtr) const
 {
   const JsContext context(jsEngine);
   v8::Local<v8::Object> thisObj = thisPtr ?
     v8::Local<v8::Object>::Cast(thisPtr->UnwrapValue()) :
     context.GetV8Context()->Global();
 
   std::vector<v8::Handle<v8::Value>> argv;
   for (const auto& param : params)
     argv.push_back(param->UnwrapValue());
 
@@ skipping 22 matching lines @@
   const v8::TryCatch tryCatch;
   v8::Local<v8::Function> func = v8::Local<v8::Function>::Cast(UnwrapValue());
   v8::Local<v8::Value> result = func->Call(thisObj, args.size(),
     args.size() ? &args[0] : nullptr);
 
   if (tryCatch.HasCaught())
     throw JsError(tryCatch.Exception(), tryCatch.Message());
 
   return JsValue(jsEngine, result);
 }