Issue 6391 - WebDriver: Fix runtime problen with Gecko and Firefox

test_runner.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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 29 matching lines @@
   chromium: chromiumProcess,
   firefox: firefoxProcess
 };
 
 function configureRunners()
 {
   let runners = "BROWSER_TEST_RUNNERS" in process.env ?
       process.env.BROWSER_TEST_RUNNERS.split(",") : [];
 
   if (runners.length == 0)
-    return ["chromium_remote"];
+    return ["chromium_remote", "firefox"];
 
   return runners.filter(runner => runnerDefinitions.hasOwnProperty(runner));
 }
 
 let runnerProcesses = configureRunners();
 
 function addTestPaths(testPaths, recurse)
 {
   for (let testPath of testPaths)
   {
@@ skipping 110 matching lines @@
 
 Promise.resolve(runBrowserTests(runnerProcesses)).catch(error =>
 {
   console.error("Failed running browser tests");
   console.error(error);
 }).then(() =>
 {
   if (unitFiles.length)
     nodeunit.reporters.default.run(unitFiles);
 });