After this is fixed we need to assess on Mac as well per this quote from our eval "Can't really answer until this is made accessible with a screen reader"

 Issue 817542  has been merged into this issue.

Also repros on this environment:

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

The zoom menu items are also not accessible.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1bcb2e391be97cd6542acd433a210a47a337771e

commit 1bcb2e391be97cd6542acd433a210a47a337771e
Author: Nektarios Paisios <nektar@chromium.org>
Date: Mon Mar 12 22:42:14 2018

Makes zoom buttons in Chrome main menu accessible to Jaws and NVDA

Screen readers now announce the correct role for the zoom in and zoom out buttons and also announce the zoom level if changed.
Announcing that these controls are buttons sends a signal to screen reader users that the menu will not close when these controls are activated.
The drawback is that the word "Alert" is prepended to the announcement of the new zoom level.

R=aleventhal@chromium.org, pbos@chromium.org

Bug:  779304 
Change-Id: Ie078d63c318a70fa64db268ac748dc2700995f55
Tested: Use zoom in and zoom out while Jaws and NVDA are running
Reviewed-on: https://chromium-review.googlesource.com/957902
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Aaron Leventhal <aleventhal@chromium.org>
Reviewed-by: Nektarios Paisios <nektar@chromium.org>
Commit-Queue: Nektarios Paisios <nektar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#542636}
[modify] https://crrev.com/1bcb2e391be97cd6542acd433a210a47a337771e/chrome/browser/ui/views/toolbar/app_menu.cc
[modify] https://crrev.com/1bcb2e391be97cd6542acd433a210a47a337771e/ui/accessibility/platform/ax_platform_node_win.cc

There is a bigger issue with zooming in the Chrome menu which has been fixed in this bug. Now, whenever the zoom level changes while using the plus or minus button in the menu, the new zoom level is announced by an alert.
The bug described in the original description of this bug is not a real bug because screen reader users should not have access to static text content via the tab order. Screen reader users can use other capabilities in their screen reader to read such text. In this case, pressing Insert+B does do the trick.
Marking as fixed.

This bug actually combined two different bugs into one and the commit above doesn't apply this this one. I've decided to archive this bug and put everything into the two areas where they belong: 

1) Zoom percentage in Customize and Control menu. Opened new bug just for that one: https://bugs.chromium.org/p/chromium/issues/detail?id=823008
- I pasted the commit into the new bug

2) Zoom dialog attached to the Omnibar. I opened this other bug for that with more details: https://bugs.chromium.org/p/chromium/issues/detail?id=823004

Please do not re-open this bug and instead put relevant comments into those bugs.