Download Chromedriver during script/build

...so that we can cache it.

script/build

@@ -12,6 +12,7 @@ const codeSignOnMac = require('./lib/code-sign-on-mac')
 const compressArtifacts = require('./lib/compress-artifacts')
 const copyAssets = require('./lib/copy-assets')
 const createWindowsInstaller = require('./lib/create-windows-installer')
+const downloadChromedriver = require('./lib/download-chromedriver')
 const dumpSymbols = require('./lib/dump-symbols')
 const generateAPIDocs = require('./lib/generate-api-docs')
 const generateMetadata = require('./lib/generate-metadata')
@@ -39,6 +40,7 @@ generateModuleCache()
 prebuildLessCache()
 generateMetadata()
 generateAPIDocs()
+downloadChromedriver()
 dumpSymbols()
   .then(packageApplication)
   .then(packagedAppPath => {

script/lib/download-chromedriver.js

@@ -29,7 +29,7 @@ module.exports = function () {
     const chromedriverDirPath = path.join(CONFIG.electronDownloadPath, 'chromedriver')
     unzipPath(chromedriverZipPath, chromedriverDirPath)
   } else {
-    throw new Error('Downloading chromedriver for platforms other than macOS is unsupported!')
+    console.log('Skipping Chromedriver download because it is used only on macOS'.gray)
   }
 }
 

script/test

@@ -5,7 +5,6 @@
 require('colors')
 const async = require('async')
 const childProcess = require('child_process')
-const downloadChromedriver = require('./lib/download-chromedriver')
 const fs = require('fs')
 const path = require('path')
 
@@ -16,8 +15,6 @@ const packagedAppPath = path.resolve(__dirname, '..', 'out', `${appName}.app`)
 const executablePath = path.join(packagedAppPath, 'Contents', 'MacOS', appName)
 const resourcePath = CONFIG.repositoryRootPath
 
-downloadChromedriver()
-
 function runCoreMainProcessTests (callback) {
   const testPath = path.join(CONFIG.repositoryRootPath, 'spec', 'main-process')
   const testArguments = [