Google Chrome 66.0.3349.0 (Official Build) canary (64-bit) (cohort: 64-Bit) 
Google Chrome 64.0.3282.167 (Official Build) (64-bit) (cohort: Stable)
Windows 10 Enterprise Version 1607		
NVDA 2017.4
Full Keyboard access enabled on Mac to allow tab to move focus between all controls	
macOS Sierra 10.12.6 with VoiceOver 7.0	

To repro:
Zoom in or out using the Chrome Zoom feature using the ctrl + shift + minus or ctrl + shift + plus keys

Screen reader issues on Windows and Mac:
Windows: From the screen reader perspective, nothing was announced and no dialog seemed to open"
Mac: Only 'zoom in' and ""zoom out' were announced, not the zoom level."

From the keyboard user perspective on Mac and Windows, there is no way to access the "restore" button to resume zoom to 100%/default. The keys themselves otherwise work.