title: selenium can't open page after set new user-data-dir
body: <p>I use python and selenium  to operate chrome,if I use default user-data-dir it works,but use new user-data-dir it blocks before opening first url.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
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  <pre class="snippet-code-js lang-js prettyprint-override"><code>  #default_path = r'C:\Users\%s\AppData\Local\Google\Chrome\User Data' % username 
      default_path = r'D:\User Data'
      option.add_argument('--user-data-dir=%s' % default_path)
      driver = webdriver.Chrome(chrome_options=option,executable_path=r'C:\Users\Administrator\Desktop\chromedriver.exe')</code></pre>
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  </div>
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  <p>After test I found the chrome blocks because it can't load google.com in china! if i don't use 'user-data-dir' argument,it use 'data:,' as default address. So I want to know how can I open chrome without open google.com as default address(such as use 'data:,' )</p>