Thanks Gene! Confirming that this does work on other OSes, though I hadn't realized it.

I've updated the priority to P3 since it seems easy to navigate back to previously used window (another Alt+Tab), but still something we can consider.

How does this work elsewhere/how should it work in cros? We just ignore Escape right now. Should escape dismiss the UI, or move the selection back to the initial window (either one would solve the problem as described in the initial bug report).

alt-escape should roll back all changes since alt was held down. It should be as if alt-tab or alt-shift-tab had not been pressed at all. So yes, move back to the initial window and not change the window stack.

If we assume escape just cancels the UI, there's no need to "move back to the initial window" as we've never moved away from it. It sounds like that's what we want to do, I was just unclear on whether escape immediately dismissed the UI or it stayed up while holding alt.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3b872a197e09c87447a6e1a8fbd5ed6e24ea1577

commit 3b872a197e09c87447a6e1a8fbd5ed6e24ea1577
Author: estade <estade@chromium.org>
Date: Tue Oct 04 23:13:42 2016

Dismiss cros alt+tab UI on escape.

BUG= 648351 

Review-Url: https://codereview.chromium.org/2396603002
Cr-Commit-Position: refs/heads/master@{#422989}

[modify] https://crrev.com/3b872a197e09c87447a6e1a8fbd5ed6e24ea1577/ash/wm/window_cycle_event_filter_aura.cc

Verified on ChromeOS 8872.18.0, 55.0.2883.20

This is not fixed on Chrome 56.0.2924.28/ChromeOS 9000.29.0 (beta channel) -- initiating alt-tab then poking escape causes a window switch.

It looks like the patch makes alt-esc equivalent to releasing alt. This isn't right. Alt-esc first has to roll back the cycling changes, then dismiss the window, since WindowCycleController::StopCycling() will commit the changes made so far.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bfcf715cb1a1dca220fdbbc662c4f875a2dbc26b

commit bfcf715cb1a1dca220fdbbc662c4f875a2dbc26b
Author: estade <estade@chromium.org>
Date: Tue Jan 03 23:14:26 2017

CrOS Alt+Tab UI: no-op when UI is aborted (instead of switching window).

Also, remove the old pre-MD code for window switching & activation.

BUG= 648351 

Review-Url: https://codereview.chromium.org/2612633002
Cr-Commit-Position: refs/heads/master@{#441242}

[modify] https://crrev.com/bfcf715cb1a1dca220fdbbc662c4f875a2dbc26b/ash/common/wm/window_cycle_controller.cc
[modify] https://crrev.com/bfcf715cb1a1dca220fdbbc662c4f875a2dbc26b/ash/common/wm/window_cycle_controller.h
[modify] https://crrev.com/bfcf715cb1a1dca220fdbbc662c4f875a2dbc26b/ash/common/wm/window_cycle_list.cc
[modify] https://crrev.com/bfcf715cb1a1dca220fdbbc662c4f875a2dbc26b/ash/common/wm/window_cycle_list.h
[modify] https://crrev.com/bfcf715cb1a1dca220fdbbc662c4f875a2dbc26b/ash/wm/window_cycle_controller_unittest.cc
[modify] https://crrev.com/bfcf715cb1a1dca220fdbbc662c4f875a2dbc26b/ash/wm/window_cycle_event_filter_aura.cc

Verified on 57.0.2987.19/9202.11.0