The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/10dc3f9ab7b6b1f0511fc1c2666e63dfc337800c

commit 10dc3f9ab7b6b1f0511fc1c2666e63dfc337800c
Author: Malay Keshav <malaykeshav@chromium.org>
Date: Fri Apr 20 20:36:39 2018

Fix default usge of display zoom and ui scale

Enabling the flag for display zoom does not disable or change the ui
scale being applied. The same is true for when we disable the display
zoom. We do not change or remove the zoom value.

This patch disables applying any display zoom when the flag is disabled
and disables applying any ui scale when the flag is enabled.

Bug:  834950 
Change-Id: I07593806f54ee7daf3b5df38023c525501d85a95
Component: Display Manager, ui scale, display zoom
Reviewed-on: https://chromium-review.googlesource.com/1020532
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#552457}
[modify] https://crrev.com/10dc3f9ab7b6b1f0511fc1c2666e63dfc337800c/ui/display/display_switches.cc
[modify] https://crrev.com/10dc3f9ab7b6b1f0511fc1c2666e63dfc337800c/ui/display/display_switches.h
[modify] https://crrev.com/10dc3f9ab7b6b1f0511fc1c2666e63dfc337800c/ui/display/manager/display_manager.cc

Is this a M67 regresion, or tied to a new feature?

This is tied to a bug that may be caused when you enable the feature -> Issue 790723

Your change meets the bar and is auto-approved for M67. Please go ahead and merge the CL to branch 3396 manually. Please contact milestone owner if you have questions.
Owners: cmasso@(Android), cmasso@(iOS), kbleicher@(ChromeOS), govind@(Desktop)

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

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4b2de223c732431bba2fb4b3218fa149bdbe9a3b

commit 4b2de223c732431bba2fb4b3218fa149bdbe9a3b
Author: Malay Keshav <malaykeshav@chromium.org>
Date: Wed Apr 25 00:03:26 2018

(merge) Fix default usge of display zoom and ui scale

Merge to M67
Enabling the flag for display zoom does not disable or change the ui
scale being applied. The same is true for when we disable the display
zoom. We do not change or remove the zoom value.

This patch disables applying any display zoom when the flag is disabled
and disables applying any ui scale when the flag is enabled.

Bug:  834950 
Change-Id: I07593806f54ee7daf3b5df38023c525501d85a95
Component: Display Manager, ui scale, display zoom
Reviewed-on: https://chromium-review.googlesource.com/1020532
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#552457}(cherry picked from commit 10dc3f9ab7b6b1f0511fc1c2666e63dfc337800c)
Reviewed-on: https://chromium-review.googlesource.com/1026911
Reviewed-by: Malay Keshav <malaykeshav@chromium.org>
Cr-Commit-Position: refs/branch-heads/3396@{#274}
Cr-Branched-From: 9ef2aa869bc7bc0c089e255d698cca6e47d6b038-refs/heads/master@{#550428}
[modify] https://crrev.com/4b2de223c732431bba2fb4b3218fa149bdbe9a3b/ui/display/display_switches.cc
[modify] https://crrev.com/4b2de223c732431bba2fb4b3218fa149bdbe9a3b/ui/display/display_switches.h
[modify] https://crrev.com/4b2de223c732431bba2fb4b3218fa149bdbe9a3b/ui/display/manager/display_manager.cc