This should be a blocker for M69 testflight.

Mrefaat: Please re-assign if you're not the right owner. 

Were you running with New UI in M68 when you upgrade to M69?

If a user has New UI manually enabled in M68 and then upgrade to M69, since M69 beta users are 50/50 on old vs. new UI, it is possible for this flip-flip from new to old because the old forcing-on flag will be overridden by the 50/50 experiment.

On fresh installation of M69 beta channel:
After completing First Run, UI-Refreshed chrome is displayed.
Force quit and Launch app, Old Chrome displayed.

Install M68 beta, with Old UI as is. No flags touched.
Upgrade to M69 beta, still on Old UI.

Video: https://drive.google.com/file/d/1-mCfC6C0NDXrT-6yk89b1NtJy8k8DBca/view

At Installation: 
Google Chrome69.0.3497.6 (Official Build) beta (64-bit)Revision3ca6d16bb111...OSiOSUser AgentMozilla/5.0 (iPhone; CPU iPhone OS 11_4 like Mac OS X) AppleWebKit/604.1.34 (KHTML, like Gecko) CriOS/69.0.3497.6 Mobile/15E148 Safari/604.1Command Line/var/containers/Bundle/Application/E1B8BC15-E1BA-4DB8-842C-F9C6A7C68131/beta.app/Chrome --flag-switches-begin --flag-switches-end


After cold start:
Google Chrome	69.0.3497.6 (Official Build) beta (64-bit)
Revision	3ca6d16bb111...
OS	iOS
User Agent	Mozilla/5.0 (iPhone; CPU iPhone OS 11_4 like Mac OS X) AppleWebKit/604.1.34 (KHTML, like Gecko) CriOS/69.0.3497.6 Mobile/15E148 Safari/604.1
Command Line	/var/containers/Bundle/Application/E1B8BC15-E1BA-4DB8-842C-F9C6A7C68131/beta.app/Chrome --flag-switches-begin --flag-switches-end
Variations	ebeb14fc-3f4a17df
38eb801c-3f4a17df
a582a1b8-ad75ce17
3042ad4b-f23d1dea
ae2dda3c-56dd17e
5ccc342e-e0fda730
9e5c75f1-386b4aaa
f79cb77b-3d47f4f4
494d8760-52325d43
3ac60855-486e2a9c
f296190c-19721340
4442aae2-75cb33fc
ed1d377-e1cc0f14
12e17bc5-e1cc0f14
75f0f0a0-a5822863
e2b18481-a5822863
e7e71889-e1cc0f14

Has anyone ever gotten the old UI on a fresh install of M69 beta?  That should be a 50/50 chance, according to the configs.  But if no one has ever seen the old UI on a fresh install, then we have a clear indication that something is wrong.

Seems like we have two different issues:

1) The original reporter was using .6 beta, which did not have the client-side changes merged.  .6 will receive the new UI 100% of the time on beta; .7 and later will get it 50/50.

2) We have conflicting server-side configs in place for M69.  There was an existing config that should have only applied to M68 but was misconfigured to include M69 as well.  That config was forcing everyone into the old UI, which is probably why we were getting the old UI 100% of the time on second launch.

Just sent https://critique.corp.google.com/#review/205876228 to remove conflicting server side config.

http://CL/205880516 landed at 1:22pm (local time). Just checked at 1:49pm by installing Chrome beta (69.0.3497.7, latest from go/bling-builds).

===== TEST #1 =====
First Run:
Old UI Shown.
chrome://version shows only one experiment:
3825fbed-cc31170b == IOSUIRefreshRolloutWithHoldback-OldUIControl

Terminated and started Chrome beta again:
Still Old UI Shown.
chrome://version shows these experiments:
ebeb14fc-3f4a17df
34a6bf44-ca7d8d80
38eb801c-3f4a17df
a582a1b8-ad75ce17
3042ad4b-f23d1dea
ae2dda3c-56dd17e
3825fbed-cc31170b
58d60df8-98e6abcd
9e5c75f1-8ad81f0d
f79cb77b-3d47f4f4
17507c76-3d47f4f4
494d8760-52325d43
3ac60855-486e2a9c
f296190c-a22f0910
4442aae2-4ad60575
ed1d377-e1cc0f14
12e17bc5-e1cc0f14
75f0f0a0-6bdfffe7
e2b18481-e1cc0f14
e7e71889-e1cc0f14

Using http://finch-hashes to translate:
AutofillResetFullServerCardsOnAuthError-Enabled
AutofillRestrictUnownedFieldsToFormlessCheckout-Default
ChromeChannelBeta-Enabled
ExpiredHistograms-ExpiredHistogramLogicEnabled
HTTP2-Control
IOSBadgedReadingListPromotion-Enabled100
IOSUIRefreshRolloutWithHoldback-OldUIControl     <<<<<<<<<======================
IOSUseWebThreadInCertVerificationController-UseDispatchAsync_Default
OmniboxBundledExperimentV1-Standard_R5
PasswordGeneration-Disabled
TranslateUserEvents-Disabled
UKM-Enabled_20180314
UMA-Population-Restrict-normal
UMA-Uniformity-Trial-1-Percent-group_20
UMA-Uniformity-Trial-10-Percent-default
UMA-Uniformity-Trial-100-Percent-group_01
UMA-Uniformity-Trial-100-Percent-V2-group_01
UMA-Uniformity-Trial-20-Percent-group_02
UMA-Uniformity-Trial-5-Percent-group_01
UMA-Uniformity-Trial-50-Percent-group_01

===== TEST #4 =====
On trial 4, I get assigned New UI.
chrome://version shows 3825fbed-3ef8e474 => IOSUIRefreshRolloutWithHoldback-NewUIExperiment

Terminated and relaunched Chrome beta.
Still showing New UI.
chrome://version shows the following experiments:
ebeb14fc-3f4a17df
38eb801c-3f4a17df
a582a1b8-ad75ce17
3042ad4b-ca54bb47
ae2dda3c-56dd17e
3825fbed-3ef8e474
9e5c75f1-8ad81f0d
f79cb77b-3d47f4f4
494d8760-52325d43
3ac60855-486e2a9c
f296190c-4ad60575
4442aae2-d7f6b13c
ed1d377-e1cc0f14
12e17bc5-e1cc0f14
75f0f0a0-4ad60575
e2b18481-3a9ae350
e7e71889-e1cc0f14

Translated:
AutofillResetFullServerCardsOnAuthError-Enabled
ChromeChannelBeta-Enabled
ExpiredHistograms-ExpiredHistogramLogicEnabled
HTTP2-PushDisabled
IOSBadgedReadingListPromotion-Enabled100
IOSUIRefreshRolloutWithHoldback-NewUIExperiment     <<<<<<<<<=============
OmniboxBundledExperimentV1-Standard_R5
PasswordGeneration-Disabled
UKM-Enabled_20180314
UMA-Population-Restrict-normal
UMA-Uniformity-Trial-1-Percent-default
UMA-Uniformity-Trial-10-Percent-group_03
UMA-Uniformity-Trial-100-Percent-group_01
UMA-Uniformity-Trial-100-Percent-V2-group_01
UMA-Uniformity-Trial-20-Percent-default
UMA-Uniformity-Trial-5-Percent-group_15
UMA-Uniformity-Trial-50-Percent-group_01

[Auto-generated comment by a script] We noticed that this issue is targeted for M-69; it appears the fix may have landed after branch point, meaning a merge might be required. Please confirm if a merge is required here - if so add Merge-Request-69 label, otherwise remove Merge-TBD label. Thanks.

No fix on client required.
See comment 12.

Verified the issue on 69.0.3497.7 beta tested on iPhone & iPad(iOS 10.3.3) and iPhone(iOS 11.4).

Below are the observations.

1. Old UI is seen on launching chrome on fresh installation on few devices. 
2. New UI is seen on fresh installation in few devices.