Can repro with browser-container-contains-ntp enabled. Can not repro with browser-container-contains-ntp disabled.

Justin could you PTAL

git log --pretty=oneline c057542..0baa5bd shows suspicious CLs:

abed6b7c1b6fee5d6f12f2e36535419dd57b60ad [iOS] Prevent frame change compensation during rotation
e2513d16ede8ecff2f0bee7856cafaacd0790b57 [iOS] Added FullscreenViewportInsetRangeChanged().
d2a03d7adb02f2a029b930c5ed170a2272113eef [ios] Refactor BrowserViewInformation

Flipping to kkhorimoto@ since abed6b7c1b6f looks very suspect and is fullscreen related, but gambard is OOO.

This is now happening on M72 beta as well. Is there any update on this bug?

gambard@ abed6b7c1b6f looks suspicious.  Can you PTAL?

This was caused by https://chromium-review.googlesource.com/c/chromium/src/+/1356588

The issue appeared on M72 because this CL was merged, from the issue 908796.

https://chromium-review.googlesource.com/c/chromium/src/+/1418051/ should fix the issue. However, I don't know if it would introduce new issues. I don't think we should have something worse than issue 908796.

Considering that it is close to stable cut, the other solution would be to revert the CL cherry-picked in that issue. I am not sure why it was cherry-picked in the first place: kkhorimoto@ wdyt?

 Issue 922845  has been merged into this issue.

Note: The title refers to MostVisited tiles, but the problem occurs for *any* page visited from NTP when phone is in landscape. I can just type in "cats" into the omnibox and get a very narrow page.

This is a regression in the latest TestFlight.

(fixing summary)

Issue 908796 was merged because the fix for Issue 915123 was dependent upon it.  We could have chosen to either merge neither of them or both of them, so we decided on merging both of them.  Issue 915123 was the more pressing issue since it was a crash, so the worst case scenario of reverting both of them would leave only Issue 908796 (a ui flicker) on M72.

That being said, I've lgtm'd crrev.com/c/1418051, since it makes sense and doesn't seem like it would introduce any new issues.

I think it's best to revert the 2 CLs used to fix crbug.com/908796. We don't know the risk of crrev.com/c/1418051 and it could cause another regression.

I would rather have crbug.com/908796 in M72 than this bug in M72. And we know reverting the 2 cls will only bring back crbug.com/908796.

Kurt: can you handle the reverts?

Adding a few others for visibility.

Okay, the 2 CLs are reverted here:

crrev.com/c/1419129
crrev.com/c/1419131

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/dc500102fb9320bfcfcf996ccd6cb5524e14b7d2

commit dc500102fb9320bfcfcf996ccd6cb5524e14b7d2
Author: Gauthier Ambard <gambard@chromium.org>
Date: Fri Jan 18 08:49:28 2019

[iOS] Reset the frame of the WebView when displaying the tab

It prevents the WebView from being wrongly resized on rotations while
not displaying it.

Bug:  920655 
Change-Id: Ia0cefaaf5c207da9b5cee2a57279f4694fff7b06
Reviewed-on: https://chromium-review.googlesource.com/c/1418051
Reviewed-by: Kurt Horimoto <kkhorimoto@chromium.org>
Reviewed-by: Justin Cohen <justincohen@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#624039}
[modify] https://crrev.com/dc500102fb9320bfcfcf996ccd6cb5524e14b7d2/ios/chrome/browser/ui/browser_view_controller.mm

Thanks, I am not merging this issue as it should have been fixed by reverting the other CL. The verification should still happen on M72.

[Auto-generated comment by a script] We noticed that this issue is targeted for M-72; it appears the fix may have landed after branch point, meaning a merge might be required. The owner of this bug should confirm if a merge is required here. If so, add Merge-Request-72 label and indicate which commits/CLs are to be merged. Otherwise, remove Merge-TBD label. Thanks.

Removing the label as it should have been fixed by reverting the other CL. The verification should still happen on M72.

Verified in 
Build: 73.0.3680.0 Canary
Device Details: iPhone 8(iOS 11.4.1), iPhone XS Max(iOS 12.1.2)

Followed the steps mentioned in comment#0. In Landscape websites doesn't render in narrow web view. Looks good

Can we verify this in M72 as well?

I checked this morning, and it looked good on 72.0.3626.70