chromium/third_party/blink/manual_tests/inspector/command-line-api.html

<script type="text/javascript" charset="utf-8">
    var $ = function() { console.log("OK") };
</script>

<p>Test for <a href="https://bugs.webkit.org/show_bug.cgi?id=20385">Bug 20385: Firebug command line extensions interfere with existing objects</a>.</p>
<p>To test, execute "$()" in the Inspector's Console. Also trying setting $.</p>