The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5f610866ab3323c4ea9b3b32a9270e6daca4902b

commit 5f610866ab3323c4ea9b3b32a9270e6daca4902b
Author: Gauthier Ambard <gambard@chromium.org>
Date: Thu Jan 17 11:43:55 2019

[iOS] Create flag for Settings UI Refresh

This CL creates the flag to be used to change the UI of Settings.

Bug: 922511
Change-Id: Ia94550261f51852620a354e4d1e6282a4013f42e
Reviewed-on: https://chromium-review.googlesource.com/c/1413606
Reviewed-by: Mark Cogan <marq@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623651}
[modify] https://crrev.com/5f610866ab3323c4ea9b3b32a9270e6daca4902b/ios/chrome/browser/about_flags.mm
[modify] https://crrev.com/5f610866ab3323c4ea9b3b32a9270e6daca4902b/ios/chrome/browser/ios_chrome_flag_descriptions.cc
[modify] https://crrev.com/5f610866ab3323c4ea9b3b32a9270e6daca4902b/ios/chrome/browser/ios_chrome_flag_descriptions.h
[modify] https://crrev.com/5f610866ab3323c4ea9b3b32a9270e6daca4902b/ios/chrome/browser/ui/ui_feature_flags.cc
[modify] https://crrev.com/5f610866ab3323c4ea9b3b32a9270e6daca4902b/ios/chrome/browser/ui/ui_feature_flags.h

Verified on 73.0.3680.0 Canary,  iPhoneXR  iOS 12.1.2
looks good.