Issue 6391 - Allow running the browser unit tests with Firefox

test/runners/chromium_download.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 58 matching lines @@
 
     let [dir, fileName] = buildTypes[platform];
     let archive = path.join(snapshotsDir, "download-cache",
                             `${chromiumRevision}-${fileName}`);
 
     return Promise.resolve()
       .then(() =>
       {
         if (!fs.existsSync(archive))
         {
-          let url = `https://www.googleapis.com/download/storage/v1/b/chromium-browser-snapshots/o/${dir}%2F${chromiumRevision}%2F${fileName}?alt=media`;
           console.info("Downloading Chromium...");
-          return download(url, archive);
+          return download(
+            `https://www.googleapis.com/download/storage/v1/b/chromium-browser-snapshots/o/${dir}%2F${chromiumRevision}%2F${fileName}?alt=media`,
+            archive);
         }
         console.info(`Reusing cached archive ${archive}`);
       })
       .then(() => unzipArchive(archive, chromiumDir))
       .then(() => chromiumDir);
   }).then(dir => getChromiumExecutable(dir));
 }
 
 module.exports.ensureChromium = ensureChromium;