The Chrome OS Canadian Multilingual keyboard layout doesn't quite work properly, but this extension restores most of the lost characters. At last, AltGr is working (mostly) as it should!

This extension can't work on certain special pages, for example any of the "chrome://" pages such as Settings or Extensions.

About the "all sites" permission: In order to fix the keyboard on every page, the extension needs to install a little piece of code on each one. It does nothing else with the the page, its information, or your typing. Everything stays local, and the extension is composed of just one javascript file.

Giddyup!