De acordo com webupd8_fix-failed-to-fetch (leia a atualização) edite os dois arquivos a seguir:
/etc/apt/sources.list.d/google-chrome.list
Mude a linha 3 de:
deb http://dl.google.com/linux/chrome/deb/ stable main
para:
deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main
Edite o /opt/google/chrome/cron/google-chrome
Altere REPOCONFIG e SSLREPOCONFIG de:
REPOCONFIG="deb http://dl.google.com/linux/chrome/deb/ stable main"
SSLREPOCONFIG="deb https://dl.google.com/linux/chrome/deb/ stable main"
para:
REPOCONFIG="deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main"
SSLREPOCONFIG="deb [arch=amd64] https://dl.google.com/linux/chrome/deb/ stable main"