https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=786909 this history is long, search on your own for more.
1. While the Hotword module was downloaded at startup, the feature was not activated without the user explicitly enabling it via the settings menu. <https://crbug.com/500922#c6>
2. Downloading the module in Chromium was a bug, and it was fixed after being reported. <https://crbug.com/50922#30>
3. The Hotword feature was dropped from Chrome not too long after, because it was an experiment that never really panned out (and was enabled by very few people).