Chrome Version       : 52.0.2740.0
OS Version: OS X 10.11.5

What steps will reproduce the problem?
1. Language & Region -> set Language to Persian
2. Press ⌘+"=" or ⌘+"+", Zooms in
3. Press ⌘+"-"

What is the expected result?

Zooms out

What happens instead of that?

Does nothing. ⌘+"_" (i.e. ⌘+Shift+"-") works though.

I haven't found another language that does this yet. Chinese, Japanese, Australian, Hebrew, French were all fine.

(in case someone is searching and using regular words like a normal person, ⌘ = Cmd or Command).