On MacOS, you can't zoom by pressing Cmd -/= as you can in most other apps (Chrome, Safari, Terminal etc.)
Steps to Reproduce:
1. Open a document
2. Press Cmd- to zoom out or Cmd= to zoom in
The letter '-' or '=' is added to the document.
The zoom level changes.
User Profile Reset: No
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36
*** This bug has been marked as a duplicate of bug 45705 ***