Tested the issue on Mac OS 10.12.6 (Retina & Non-retina) using chrome M60 #60.0.3112.90  and M62 #62.0.3181.0 and didn't observe lik attached screenshot in original comment #0.

Observed different behavior of drop down in chrome and firefox.

Attached screencast for reference.

@mcousins-- Could you please check attached screencast and confirm us if the firefox behavior is the expected result or please help us by providing the expected result screenshot.

Thanks!

I believe either the wrong screencast was attached (the one attached shows trying to attach an executable to a gmail.  I will see if I can record a screencast or something similar to show the issue.

I did test in Firefox and Edge, in both cases the dropdown list under the input appeared correctly on both monitors.  Only in Chrome does the dropdown not appear on one of the monitors as it is rendered off screen.

Thank you for providing more feedback. Adding requester "hdodda@chromium.org" to the cc list and removing "Needs-Feedback" label.

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

Heres a .mov recording of the issue - this is on the laptop screen (1920x1200 Non-Retina) 

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Chrome.mov 1.4 MB Download

Regrests for inconvenience about the screencast in comment #2. Attached new screencast .

Tested the same issue on Retina and Non-Retina macusing chrome M60 #60.0.3112.90  with following resolutions and the dropdown was displayed just below the input field:
Retina Mac    external monitor
1920*1200     1900 * 1200
              1680 * 1050 
              1440 * 900
@mcousins-- Could you please confirm if this is reproduced only on particular resolutions or reproduced on every resolutions.

Thanks!

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	753820 (1).mp4 1.3 MB View Download

Unfortunately I can only test a few resolutions.  I am on a non-retina Macbook (1920x1200) and using the original Cinema Display (2560x1600). Here are a few things to note:

1) If I unplug the external display, the dropdown renders on the laptop screen correctly under the input field. Its only when plugged in with the second screen it fails to render correctly.

2) I changed the external monitor to 1600x1000 and it would no longer render the dropdown on either screen in this case (even moving the browser didn't show it)

3) With the external set to 2048x1280 it did still work on the external.

The reason I started looking into this was a colleagues Windows 10 computer with external - when he had the Chrome window on one screen was rendering the list on the other screen. So it does seem like this can happen.

Looking at the resolutions you tested, it seems like the external monitor was never higher than the laptop resolution, wondering if that could be the issue?

Thank you for providing more feedback. Adding requester "hdodda@chromium.org" to the cc list and removing "Needs-Feedback" label.

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

I did just try both the laptop and the desktop set to 1600x1000 - it worked the same way as the default resolution, appeared on the external and did not appear on the laptop. Am not sure how the Mac internally reports resolution when changed from default to scaled, so it may not be an apples to apples comparison.  

Am going to plug in a different external monitor and check it on that.  Let me know if there are any other things you would like me to check.

Just tried with an external monitor and the same issue happened. That external had a max resolution of 1920x1080.

Here are my laptops specs, its an older model and its a few releases of OS X behind (due to VPN Software issues, I cannot upgrade at this time)

Cheers,
Matt

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As mentioned in the Comment #9, tried with lower resolution on external monitor than laptop resolution and with other combination of resolutions. But, couldn’t reproduce the issue.

Could someone from MTV look into this issue as we don’t have the reported configuration with higher resolutions above 1920*1200. Adding "TE-NeedsTriageFromMTV" label for further triage.

mcousins@ Is this still happening on the latest OS / Chrome on MacOSX?
Or can anyone confirm in what condition this is happening (just re-confirm
the configuration of the original report is fine)?

Unfortunately I cannot update to the latest OS due to VPN software issues, but the issue is still happening in 63.0.3239.108 (Official Build) (64-bit)

I also noticed on the monitor where it does draw at the right location that it is sporadic as to whether the really long list draws with a scrollbar or not - when it does the dropdown renders under the control and stops at the bottom of the browser. When it doesn't it seems to center over the control and draws off screen at the top and bottom.  Some of that may be based on the browsers position on screen.

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Thank you for providing more feedback. Adding requester "kochi@chromium.org" to the cc list and removing "Needs-Feedback" label.

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