Issue 5013 - Make parameter const ref when applicable.

src/WebRequestJsObject.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 98 matching lines @@
       using AdblockPlus::Utils::ToV8String;
       v8::Isolate* isolate = arguments.GetIsolate();
       return v8::ThrowException(ToV8String(isolate, e.what()));
     }
     thread->Start();
     return v8::Undefined();
   }
 }
 
 AdblockPlus::JsValuePtr AdblockPlus::WebRequestJsObject::Setup(
-    AdblockPlus::JsEnginePtr jsEngine, AdblockPlus::JsValuePtr obj)
+    const AdblockPlus::JsEnginePtr& jsEngine, const AdblockPlus::JsValuePtr& obj)
 {
   obj->SetProperty("GET", jsEngine->NewCallback(::GETCallback));
   return obj;
 }