Does Chrome use XPath 2.0?

Google Chrome (or Chromium) still uses libxml2 thus is limited to XPath 1.0. Cf. this Readme from the source.

No, Chrome uses XPath 1.0.

You can simplify your XPath expression to just a v2.0 function to see this:

$x("lower-case('ABC')")
SyntaxError: Failed to execute 'evaluate' on 'Document': The string 'lower-case('ABC')' is not a valid XPath expression.

Trying any other XPath 2.0 function such as current-date() will yield a similar error.

There is no built-in way of definitively determining the version of an XPath implementation other than by such probes.

XSLT, on the other hand, has system-property('xsl:version') for determining version 1.0 versus 2.0.