jtcgiants56@ Thanks for the issue.

Tested this issue on Windows 10 and Mac OS 10.12.6 on the reported version 66.0.3359.45 and the latest Canary and unable to reproduce the issue by following the below steps.

1. Launched Chrome version 65.0.3325.125 and upgraded to 66.0.3359.45 build.
2. typed in the omnibox and could not observe any floating on the omnibox.
3. Tried on a build without upgrading and couldn't observe any issues.
Attached is the screen cast for reference.

Request you to retry the issue on a new chrome profile without any flags/extensions and update the thread with the observations.

Thanks..

Deleted: 824627.mp4 1.5 MB

	824627.mp4 1.5 MB View Download

Hello, I've created a new profile with no extensions and disabled all flags. I experience the same behavior. 

Thank you for providing more feedback. Adding the requester to the cc list.

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

jtcgiants56@ Thanks for the feedback.

Re-tested this issue on Windows 10, Mac OS 10.12.6 and Ubuntu 14.04 on the reported version 66.0.3359.45 and the latest Canary 67.0.3379.0 and unable to reproduce the issue.
Can observe no issues while typing on the omnibox.

Adding 'UI>Browser>Omnibox' component and requesting someone from that team to please look into this issue and help in further triaging.

Thanks..

I would suspect something relating to non-integral DSFs.  Reporter, what's your system UI zoom/scale factor set to?

I have a custom DPI scaling of 115% in windows 10. Turning that off the issue stops. Turning it back on the issue starts again.

Thank you for providing more feedback. Adding the requester to the cc list.

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

jtcgiants56@ Thanks for the feedback.

Able to reproduce this issue on Windows 10 on the latest Canary 67.0.3379.0 and Beta 66.0.3359.45 as per comment #7.
While custom setting the scaling to 115% on Windows, can observe that Chrome omnibox is floating while typing.

Note: Issue is not observed on Mac OS 10.12.6 and Ubuntu 14.04 by launching chrome with --device-scale-factor=1.5 and even tried changing the system scaling and no issue is observed.

Bisect Information:
===================
Good Build: 66.0.3347.0 (Revision - 536620)
Bad Build : 66.0.3348.0 (Revision - 536934)

On executing the Chromium bisect script, below is the Changelog URL:

https://chromium.googlesource.com/chromium/src/+log/001696336f3e1333dbb085aed18f78236d8d8c5e..d3ccb60b66b07a34e99a77899acce76a860d867a

From the above Changelog, suspecting the below change:
Reviewed-on: https://chromium-review.googlesource.com/912851

tapted@ Please check and confirm if this issue is related to your change, else help us in assigning to the right owner.

Adding ReleaseBlock-Stable for M-66 as this is a recent regression. Please feel free to remove it if it is not applicable.

Thanks.

https://chromium-review.googlesource.com/c/chromium/src/+/981970

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/43fdbea70216927d5b53a063ddbf81e6dbee373c

commit 43fdbea70216927d5b53a063ddbf81e6dbee373c
Author: Trent Apted <tapted@chromium.org>
Date: Wed Mar 28 01:14:24 2018

Fix omnibox dropdown bounds setting on non-integral scale factors

Care needs to be taken when querying the current Widget bounds since
it may be rounded up from a prior call to SetBounds() on screens with
non-integral scale factors.

To fix, never ask the Widget for its current bounds. Instead, just
assume the last *set* bounds is where the shrink animation should start
from.

Bug:  824627 ,  629363 
Change-Id: I6914f5a779ff57f9fa1c10aefcd04579784d73ca
Reviewed-on: https://chromium-review.googlesource.com/981970
Commit-Queue: Trent Apted <tapted@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546354}
[modify] https://crrev.com/43fdbea70216927d5b53a063ddbf81e6dbee373c/chrome/browser/ui/views/omnibox/omnibox_popup_contents_view.cc

The 3382 canary branched at r546346 so this will need to wait another day to verify.

Able to reproduce this issue on Windows 10 on the reported version 66.0.3359.45 and the issue is fixed on the latest Canary 67.0.3383.0.

After custom setting the scaling to 115% on Windows, cannot observe any floating while typing in the omnibox.
Attached is the screen cast for reference.

Hence adding TE verified labels as the fix is working as intended.

Thanks..

Deleted: 824627-M67.mp4 1.4 MB

	824627-M67.mp4 1.4 MB View Download

Thanks for verifying! Requesting merge of r546354 to m66.

This bug requires manual review: M66 has already been promoted to the beta branch, so this requires manual review
Please contact the milestone owner if you have questions.
Owners: cmasso@(Android), cmasso@(iOS), josafat@(ChromeOS), abdulsyed@(Desktop)

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

Approved branch:3359

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8bc9cf9d0e9f6d22768a8c60fb8ff29b9fa87551

commit 8bc9cf9d0e9f6d22768a8c60fb8ff29b9fa87551
Author: Trent Apted <tapted@chromium.org>
Date: Thu Mar 29 21:06:32 2018

[merge-m66] Fix omnibox dropdown bounds setting on non-integral scale factors

Care needs to be taken when querying the current Widget bounds since
it may be rounded up from a prior call to SetBounds() on screens with
non-integral scale factors.

To fix, never ask the Widget for its current bounds. Instead, just
assume the last *set* bounds is where the shrink animation should start
from.

Bug:  824627 ,  629363 
Change-Id: I6914f5a779ff57f9fa1c10aefcd04579784d73ca
Reviewed-on: https://chromium-review.googlesource.com/981970
Commit-Queue: Trent Apted <tapted@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#546354}(cherry picked from commit 43fdbea70216927d5b53a063ddbf81e6dbee373c)
Reviewed-on: https://chromium-review.googlesource.com/986952
Reviewed-by: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/branch-heads/3359@{#505}
Cr-Branched-From: 66afc5e5d10127546cc4b98b9117aff588b5e66b-refs/heads/master@{#540276}
[modify] https://crrev.com/8bc9cf9d0e9f6d22768a8c60fb8ff29b9fa87551/chrome/browser/ui/views/omnibox/omnibox_popup_contents_view.cc

Able to reproduce this issue on Windows 10 on the reported version 66.0.3359.45 and the issue is fixed on the latest Beta 66.0.3359.81.

After custom setting the scaling to 115% on Windows, cannot observe any floating while typing in the omnibox.
Attached is the screen cast for reference.

Hence adding TE verified labels as the fix is working as intended.

Thanks..

Deleted: 824627-M66.mp4 1.0 MB

	824627-M66.mp4 1.0 MB View Download

Confirm issue fixed as well on 66.0.3359.81.