title: Headless Chrome REPL not working
body: <p>When I try to run:</p>
  
  <pre><code>google-chrome --headless --disable-gpu --repl http://google.com
  </code></pre>
  
  <p>getting infinite:</p>
  
  <pre><code>[0829/155519.758686:INFO:headless_shell.cc(303)] Type a Javascript expression to evaluate or "quit" to exit.
  &gt;&gt;&gt; {"result":{"type":"undefined"}}
  &gt;&gt;&gt; {"result":{"type":"undefined"}}
  &gt;&gt;&gt; {"result":{"type":"undefined"}}
  &gt;&gt;&gt; {"result":{"type":"undefined"}}
  ...
  </code></pre>
  
  <p>Google Chrome 60.0.3112.113 on Ubuntu 16.04</p>
  
  <p>Is it a bug in Chrome?</p>