Seems more like an issue with UI>Shell>Immersive unless alt-tab always involves OverviewMode.

Can confirm, this has been broken for a while on dev channel and is becoming quite annoying. It also happens when you full-screen open-as-window apps, so it might not just be related to immersive mode.

 Issue 340339  really sounds like a likely culprit, the timeframe seems right.

Moving this nonessential bug to the next milestone.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

This hasn't been touched in over a month and has now cycled into beta channel. Do we really not care about breakages of basic features that have been working for years reaching stable?

I have a patch which fixes this, writing a test for this is proving difficult though.

 Issue 637071  has been merged into this issue.

I found out why I couldn't test this in ash_unittests, we rely on the browser to forward the accelerator after it decides the fullscreen window is not going to handle the event. I've updated the test to simply verify the event will be passed onto the browser and uploaded my fix in https://codereview.chromium.org/2252673002

flackr@ do you need approval to merge to M53 cros?

Yes, this is broken in M53 and marked a release blocker so this would need to be merged back, but it's not landed yet.

From  crbug.com/637071  having the #ash-enable-window-cycle-ui flag enabled fixes the issue. Can we merge back the new ui?

#12, I would not go as far as merging Alt+Tab in M-53 and certainly not because of this issue. I think we can bake it some more in Dev and Beta channels.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/66b4142cfaf0acc038f220b6288089f8a60b923d

commit 66b4142cfaf0acc038f220b6288089f8a60b923d
Author: flackr <flackr@chromium.org>
Date: Wed Aug 17 19:54:27 2016

Don't handle the tab press event in the window cycle event filter.

Because fullscreen windows are allowed to handle alt+tab, we have to be careful
not to handle the tab press event in the window cycle event filter as it will
be treated as a fullscreen window preventing alt-tabbing.

BUG= 622396 
TEST=WindowCycleControllerTest.TabPastFullscreenWindow,WindowCycleControllerTest.TabKeyNotLeaked

Review-Url: https://codereview.chromium.org/2252673002
Cr-Commit-Position: refs/heads/master@{#412616}

[modify] https://crrev.com/66b4142cfaf0acc038f220b6288089f8a60b923d/ash/wm/window_cycle_controller_unittest.cc
[modify] https://crrev.com/66b4142cfaf0acc038f220b6288089f8a60b923d/ash/wm/window_cycle_event_filter_aura.cc

As far as I can tell there is no disable flag for the new UI, Evan is that correct? In which case we can't really test this on canary but I have manually tested this on a local build on M53. Adding merge requested.

correct, no way to test on canary

Your change meets the bar and is auto-approved for M53 (branch: 2785)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cc813d84d461f08d853e621a1fda109bfe78060e

commit cc813d84d461f08d853e621a1fda109bfe78060e
Author: Robert Flack <flackr@chromium.org>
Date: Sat Aug 20 03:16:19 2016

Don't handle the tab press event in the window cycle event filter.

Because fullscreen windows are allowed to handle alt+tab, we have to be careful
not to handle the tab press event in the window cycle event filter as it will
be treated as a fullscreen window preventing alt-tabbing.

BUG= 622396 
TEST=WindowCycleControllerTest.TabPastFullscreenWindow,WindowCycleControllerTest.TabKeyNotLeaked
TBR=varkha@chromium.org

Review-Url: https://codereview.chromium.org/2252673002
Cr-Commit-Position: refs/heads/master@{#412616}
(cherry picked from commit 66b4142cfaf0acc038f220b6288089f8a60b923d)

Review URL: https://codereview.chromium.org/2260973003 .

Cr-Commit-Position: refs/branch-heads/2785@{#692}
Cr-Branched-From: 68623971be0cfc492a2cb0427d7f478e7b214c24-refs/heads/master@{#403382}

[modify] https://crrev.com/cc813d84d461f08d853e621a1fda109bfe78060e/ash/wm/window_cycle_controller.cc
[modify] https://crrev.com/cc813d84d461f08d853e621a1fda109bfe78060e/ash/wm/window_cycle_controller_unittest.cc

Chrome OS version 53.0.2785.128/8530.89.0 samus