I can reproduce this on a recent ToT build (9/1) but not on 61.0.3163.70.

Once the on screen keyboard disappears, the dropdown menu seems to work as expected.

hcarmona@ - Any thoughts?

Not settings related, not sure who to assign this to.

Able to reproduce in minimal select/option example, check out:
http://output.jsbin.com/caxakexazi

Perhaps a CL can be identified using bisect-builds.py, assuming that the on-screen keyboard is available on ChromeOS on Linux. Something as follows:

./tools/bisect-builds.py -b <bad_revision> -g <good_revision> -a chromeos --user-data-dir=/tmp/debug

Clicking the dropdown a second time works OK, so this is not urgent, and as mentioned is not likely Settings specific.

-> a11y triage

Any update on this? We are planning a stable RC next week and this bug is marked as a blocker.

Whom is the right owner here?

Any update on this one? We are planning to build a R62 stable RC the evening of the 19th, so we would need to have all fixes merged back to 62 in ~24 hours. 

Upping priority as we build the R62 stable RC tomorrow, we need a fix in the next 24 hours.

Based on #4 I'm removing RBS here.

This sounds like an interaction between VK and selections. Retagging components to get this in front of people who can do something about it.

Remove Blink>Editing since drop-downs == SELECT element which isn't related to
selection.

It seems showing virtual keyboard makes popup window == drop-down menu confusion.
drop-down menu window may appear outside window. 

A similar issue ( crbug.com/756554 ) is filed. I will take a look.

shend@ is looking at this issue now. Thanks!

I wrote that  crbug.com/756554  was similar to this issue, but it seems to have a different cause. 

It seems like hiding the virtual keyboard sends a resize message [1], which causes popups to hide [2]. One solution is to somehow detect this case and not hide the popups.

[1] https://cs.chromium.org/chromium/src/ui/keyboard/keyboard_controller.cc?type=cs&l=354
[2] https://cs.chromium.org/chromium/src/content/renderer/render_view_impl.cc?type=cs&q=OnResize+hidepopups&l=2056

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/36f4d544f37aec38256e4daeeef70228ad0a0436

commit 36f4d544f37aec38256e4daeeef70228ad0a0436
Author: Darren Shen <shend@chromium.org>
Date: Mon Feb 12 04:45:15 2018

[VK] Don't hide popups when resizing to the same size.

Currently, clicking on a dropdown when the VK is active will cause
the VK to hide, which sends out a resize message to RenderViewImpl,
which then forces the newly opened dropdown to hide again.

The resize message sent by the VK doesn't actually change the size,
so we can prevent the popup from hiding if the new requested size
is the same as the old. The hope is that this doesn't affect any
other existing behaviour.

Bug:  761908 
Change-Id: I0d2d7e876b42cced2be867ebc5ad3432a4d045c7
Reviewed-on: https://chromium-review.googlesource.com/909869
Reviewed-by: Yuichiro Hanada <yhanada@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Darren Shen <shend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#536028}
[modify] https://crrev.com/36f4d544f37aec38256e4daeeef70228ad0a0436/content/renderer/render_view_impl.cc