The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/65fd3130d06c8d9abcd633a341dd705eb105793a

commit 65fd3130d06c8d9abcd633a341dd705eb105793a
Author: Chris Lu <thegreenfrog@chromium.org>
Date: Tue Jul 31 23:29:54 2018

[ios] Fix Tabgrid UI imperfections

- Moves GridViewCntroller inset adjustments in -viewDidAppear and -willTransitionToSize to -viewDidlayoutSubviews. The tradeoffs is that -viewDidLayoutSubviews is called many more times than the other two, hence the original choice to stay away from it. However, the current approach gives a glitchy-like UI experience when rotating.
- Updates Remote Tabs insets with horizontal safe area of scroll view if not on the screen. Doesn't update insets if visible since it will then have the right safe area already. This is still a hack, but a more comprehensive coverage so that it never ends up encroaching the safe area.

Video: https://drive.google.com/open?id=1jzP0ClCOn0uQTZC9hJ2g0FUWsF-nSuqV

Bug:  868270 ,  868285 , 868658
Change-Id: Ia50146e1be9dfdde74bbf3e7d6b6042168b2ce8a
Reviewed-on: https://chromium-review.googlesource.com/1153391
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Reviewed-by: Kurt Horimoto <kkhorimoto@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579618}
[modify] https://crrev.com/65fd3130d06c8d9abcd633a341dd705eb105793a/ios/chrome/browser/ui/tab_grid/grid/grid_view_controller.mm
[modify] https://crrev.com/65fd3130d06c8d9abcd633a341dd705eb105793a/ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.mm

Verified on Canary on 8/1

Does this need to be merged to M69?

Approved.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/711f9aeae17c8e1fbc17802688113520c1fb4637

commit 711f9aeae17c8e1fbc17802688113520c1fb4637
Author: sczs <sczs@chromium.org>
Date: Thu Aug 02 16:41:36 2018

[ios] Fix Tabgrid UI imperfections

- Moves GridViewCntroller inset adjustments in -viewDidAppear and -willTransitionToSize to -viewDidlayoutSubviews. The tradeoffs is that -viewDidLayoutSubviews is called many more times than the other two, hence the original choice to stay away from it. However, the current approach gives a glitchy-like UI experience when rotating.
- Updates Remote Tabs insets with horizontal safe area of scroll view if not on the screen. Doesn't update insets if visible since it will then have the right safe area already. This is still a hack, but a more comprehensive coverage so that it never ends up encroaching the safe area.

Video: https://drive.google.com/open?id=1jzP0ClCOn0uQTZC9hJ2g0FUWsF-nSuqV

TBR=thegreenfrog@chromium.org

(cherry picked from commit 65fd3130d06c8d9abcd633a341dd705eb105793a)

Bug:  868270 ,  868285 , 868658
Change-Id: Ia50146e1be9dfdde74bbf3e7d6b6042168b2ce8a
Reviewed-on: https://chromium-review.googlesource.com/1153391
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Reviewed-by: Kurt Horimoto <kkhorimoto@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#579618}
Reviewed-on: https://chromium-review.googlesource.com/1160875
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Cr-Commit-Position: refs/branch-heads/3497@{#337}
Cr-Branched-From: 271eaf50594eb818c9295dc78d364aea18c82ea8-refs/heads/master@{#576753}
[modify] https://crrev.com/711f9aeae17c8e1fbc17802688113520c1fb4637/ios/chrome/browser/ui/tab_grid/grid/grid_view_controller.mm
[modify] https://crrev.com/711f9aeae17c8e1fbc17802688113520c1fb4637/ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.mm

Verified in build 69.0.3497.31 Beta on iPhoneX iOS 11.4, iPhone 7+ iOS 10.3.3