I am pleased to hear of these requirements. +1 to ensuring keyboard only access.

Note: I just built these requirements from the normal Chrome browser shortcuts and behaviour. So there should already be infrastructure to do this, just something is stopping it from working.

WIP screencast of Alt-F, Alt-E and Shift+Alt+T shortcuts.

Deleted: Video-Wed-Mar-21-2018-17-10-38.webm 2.5 MB

	Video-Wed-Mar-21-2018-17-10-38.webm 2.5 MB View Download

Looks good!

Hi Alan,

Any update on this? (Is there a CL you can just land?)

The WIP CL is: https://chromium-review.googlesource.com/c/chromium/src/+/977521
I inherit from the accessibility pane focus system in order to get focus controls for all the content settings buttons in the frame.

During review I learned that it is meant to integrate with the F6 pane focus shortcut key and making that work is best done by refactoring the BrowserViewButtonProvider to represent this alternate toolbar pane as an F6 focus target which may be the hosted app button container or the main tabbed UI toolbar. This refactor would be the same as what's blocking adding the translate, credit card and password manager bubble icons to the hosted app frame.

It's probably best if I land just Shift-Alt-T, Alt-E and Alt-F for now and have a TODO for F6 that's pending the refactor.

Example of the default focus ring on the hosted app menu button, this is inconsistent with its sibling buttons and the main app menu button.

Deleted: focus-ring.png 3.8 KB

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The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/89ad7704f70509658f2ce4a4c8da454e75c46949

commit 89ad7704f70509658f2ce4a4c8da454e75c46949
Author: Alan Cutter <alancutter@chromium.org>
Date: Tue Apr 10 04:22:31 2018

Refactor browser_non_client_frame_view_ash_browsertest.cc

This CL refactors browsertests in browser_non_client_frame_view_ash_browsertest.cc.

The HostedAppNonClientFrameViewAshTest test is split up into smaller tests for
theme color, content setting icons and browser action icons.

The BrowserNonClientFrameViewAshTest tests reduce their boiler plate code with
a GetFrameViewAsh() helper function.

Bug:  822146 
Change-Id: I2fc50086f50d719873cf8b18fb044c2d63f1e8c8
Reviewed-on: https://chromium-review.googlesource.com/994912
Commit-Queue: Alan Cutter <alancutter@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: calamity <calamity@chromium.org>
Cr-Commit-Position: refs/heads/master@{#549420}
[modify] https://crrev.com/89ad7704f70509658f2ce4a4c8da454e75c46949/chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.cc
[modify] https://crrev.com/89ad7704f70509658f2ce4a4c8da454e75c46949/chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h
[modify] https://crrev.com/89ad7704f70509658f2ce4a4c8da454e75c46949/chrome/browser/ui/views/frame/browser_non_client_frame_view_ash_browsertest.cc
[modify] https://crrev.com/89ad7704f70509658f2ce4a4c8da454e75c46949/chrome/browser/ui/views/frame/hosted_app_button_container.h
[modify] https://crrev.com/89ad7704f70509658f2ce4a4c8da454e75c46949/chrome/browser/ui/views/location_bar/content_setting_image_view.cc
[modify] https://crrev.com/89ad7704f70509658f2ce4a4c8da454e75c46949/chrome/browser/ui/views/location_bar/content_setting_image_view.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/167dfe8de1bd028acd8cdd80709fd1965e30384a

commit 167dfe8de1bd028acd8cdd80709fd1965e30384a
Author: Alan Cutter <alancutter@chromium.org>
Date: Wed Apr 11 09:06:00 2018

Enable keyboard shortcuts for hosted app window frames

This CL enables the following keyboard shortcuts for hosted
app windows:
 - Shift-Alt-T: Focus window frame toolbar buttons
 - Alt-E and Alt-F: Open app menu
 - F6: Cycle focus between frame buttons and web contents.

Screencast: https://bugs.chromium.org/p/chromium/issues/attachment?aid=330498&signed_aid=BFJfbOWHFSLjA4dEetB3SA==&inline=1

Bug:  822146 
Change-Id: Ieb00735dc92c914cb2eb2022bdbd7d72e9c3b603
Reviewed-on: https://chromium-review.googlesource.com/977521
Commit-Queue: Alan Cutter <alancutter@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#549834}
[modify] https://crrev.com/167dfe8de1bd028acd8cdd80709fd1965e30384a/chrome/browser/ui/browser_command_controller.cc
[modify] https://crrev.com/167dfe8de1bd028acd8cdd80709fd1965e30384a/chrome/browser/ui/browser_command_controller.h
[modify] https://crrev.com/167dfe8de1bd028acd8cdd80709fd1965e30384a/chrome/browser/ui/views/frame/browser_non_client_frame_view_ash_browsertest.cc
[modify] https://crrev.com/167dfe8de1bd028acd8cdd80709fd1965e30384a/chrome/browser/ui/views/frame/browser_view.cc
[modify] https://crrev.com/167dfe8de1bd028acd8cdd80709fd1965e30384a/chrome/browser/ui/views/frame/hosted_app_button_container.cc
[modify] https://crrev.com/167dfe8de1bd028acd8cdd80709fd1965e30384a/chrome/browser/ui/views/frame/hosted_app_button_container.h
[modify] https://crrev.com/167dfe8de1bd028acd8cdd80709fd1965e30384a/chrome/browser/ui/views/frame/hosted_app_menu_button.cc
[modify] https://crrev.com/167dfe8de1bd028acd8cdd80709fd1965e30384a/chrome/browser/ui/views/frame/toolbar_button_provider.h
[modify] https://crrev.com/167dfe8de1bd028acd8cdd80709fd1965e30384a/chrome/browser/ui/views/toolbar/toolbar_view.cc
[modify] https://crrev.com/167dfe8de1bd028acd8cdd80709fd1965e30384a/chrome/browser/ui/views/toolbar/toolbar_view.h