Same issue on the added platforms

What steps will reproduce the problem?
(1) F6 or Search+6 to focus Omnibox and tab to try to access to an extension icon 
(2) Try to open the context menu to remove the extension

Friendly ping - any thoughts on who can own this? 

I can give this a try.

This is also applicable to Windows with all AT software.
Google Chrome 64.0.3251.0 (Official Build) canary (64-bit) (cohort: 64-Bit)
Windows 10 Enterprise Version 1607 Build 14393.1770
NVDA 2017.3
JAWS 2018.1710.42 private preview release
ZoomText Private Beta -  11.7.11.410

# Open AT software and Chrome, extension previously installed 
# Press F6 to put focus in Omnibox
# Tab to an extension 
Expected: way to open context menu to delete the extension
Actual: no way to do so via keyboard. If I use ZoomText and right click with a mouse, I can open the dialog to remove the extension. However, ZoomText doesn't read the contents of that dialog. I can still press the buttons on that dialog. 

The NextAction date has arrived: 2017-11-03

I had a brief look at this, and indeed, there's no way to get at the context menu. macOS doesn't have any native way to access that menu without using VoiceOver (with VoiceOver it's ctrl-option-shift-m). There's two things we could do:

* Promote those items into the system menus, like we did with the tab context menu
* Add a chrome-wide binding for "open context menu" and apply it everywhere

I'm leaning towards the latter right now - something like ctrl-space (by analogy with ctrl-click, which also opens the context menus).

hwi@, what do you think?

Ooh, or: down arrow? :)

+dmazzoni@, +nektar@, could you provide your perspectives on this? 

re: comment 10 ( crbug.com/696268#c11 )

The latter option "chrome-wide binding, e.g. ctrl-space on mac to open context menu" seems very useful. 

Since adding a shortcut is very difficult to revert, more perspectives at this point would be helpful. Please add who has related works and concerns on this. 

Thanks!

Also, to expand c12, for the shortcut consideration, the keys might differ on each OS, e.g. alt-space on CrOS (anology with alt-click).

friendly ping - any updates on this? 

The NextAction date has arrived: 2018-01-08

I think this needs a proper design proposal from me, since as hwi@ mentioned it's difficult to revert adding a key binding. I'll draft something and circulate it this week.

The NextAction date has arrived: 2018-01-15

a11y-testers, could you try again on Windows? Nektarios is able to do it. Tab to the extension icon and then press the context menu key on your keyboard OR Shift+F10.

If that works, please KEEP THE BUG OPEN but remove all platforms other than Mac and take it out of the Windows push. The Mac bug is still valid but I don't think this should be part of the WIndows push if it's fixed there.

Because this button is announced as 'button sub menu' and not just 'button' I feel that arrow keys should activate the menu.
Instead, arrow up or down will do the same action as pressing enter.

The Chrome menu is announced to screen reader users in the same way 'button sub menu' but in this case they can press down arrow to access this menu. On the Chrome menu, context key does not work.

These buttons may visually be very different, but to screen reader users they are presented in the same manner and should have the same methods to access them.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/735437bf18ccbc24d73032e6bd3936a86dbef317

commit 735437bf18ccbc24d73032e6bd3936a86dbef317
Author: Elly Fong-Jones <ellyjones@chromium.org>
Date: Thu Oct 18 12:31:59 2018

views: open context menus on extension actions on down arrow

These buttons have two modes: a context menu and an "activation", which usually
shows a popup but may also take an action on the page or similar. They
subclass MenuButton, so down-arrow is wired to activation instead of to opening
the menu by default. This change causes extension actions to always open their
context menu on down-arrow instead of activating, since otherwise the context
menu is keyboard-inaccessible.

Bug:  696268 
Change-Id: If0f12c3ac5b1168cc74ea5df848ecf30d0662e09
Reviewed-on: https://chromium-review.googlesource.com/c/1286738
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600736}
[modify] https://crrev.com/735437bf18ccbc24d73032e6bd3936a86dbef317/chrome/browser/ui/views/toolbar/toolbar_action_view.cc
[modify] https://crrev.com/735437bf18ccbc24d73032e6bd3936a86dbef317/chrome/browser/ui/views/toolbar/toolbar_action_view.h

Down arrow now always opens the context menu rather than activating extension icons.