Issue 5013 - Use const JsValue and pass reference where applicable

test/FilterEngine.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 216 matching lines @@
       exampleSubscriptionResponse.responseStatus = 200;
       exampleSubscriptionResponse.status = WebRequest::NS_OK;
       exampleSubscriptionResponse.responseText = "[Adblock Plus 2.0]\n||example.com";
       webRequest->responses.emplace(subscriptionUrlPrefix, exampleSubscriptionResponse);
       createParams.preconfiguredPrefs["first_run_subscription_auto_select"] = jsEngine->NewValue(false);
       isConnectionAllowed = true;
       createParams.isConnectionAllowedCallback = [this](const std::string* allowedConnectionType)->bool{
         capturedConnectionTypes.Add(allowedConnectionType);
         return isConnectionAllowed;
       };
-      jsEngine->SetEventCallback("filterChange", [this](const JsValueList& params/*action, item*/)
+      jsEngine->SetEventCallback("filterChange", [this](const JsConstValueList& params/*action, item*/)
       {
         ASSERT_EQ(2u, params.size());
         if (params[0]->AsString() == "subscription.downloadStatus")
         {
           {
             std::lock_guard<std::mutex> lock(downloadStatusChanged.mutex);
             downloadStatusChanged.url = params[1]->GetProperty("url")->AsString();
           }
           downloadStatusChanged.cv.notify_one();
         }
@@ skipping 838 matching lines @@
     filterEngine->SetAllowedConnectionType(&testConnection);
     auto subscription = EnsureExampleSubscriptionAndForceUpdate("subB");
     EXPECT_EQ("synchronize_ok", subscription->GetProperty("downloadStatus")->AsString());
     EXPECT_EQ(1u, subscription->GetProperty("filters")->AsList().size());
     auto capturedConnectionTypes = this->capturedConnectionTypes.GetStrings();
     ASSERT_EQ(1u, capturedConnectionTypes.size());
     EXPECT_TRUE(capturedConnectionTypes[0].first);
     EXPECT_EQ(testConnection, capturedConnectionTypes[0].second);
   }
 }