California already has a ban on hi-capacity magazines (over 10 rounds). So why mention just Glocks. Many double-stack semi-automatic pistols can load 10 rounds with restricted capacity magazines.
If California bans anything it will be at least all semi-automatic pistols and maybe all hand guns.
Wouldn't surprise me to see that happen in the near future.
If you want to keep your guns, leave California. It's really an effed up state for gun owners.