Visit chrome://help And see that the Chrome version is prominently listed.

e.g. "Version 62.0.3166.0 (official Build) dev (32-bit)"

Clicking into "Detailed build information" lets you see the Chrome OS build number.


But Chrome builds are not unique to Chrome OS builds.  If there's something wrong with the PFQ we can have the same Chrome build in weeks' worth of Chrome OS builds.  We don't want to encourage users to report their Chrome build instead of Chrome OS build.