lod@ could you PTAL.

Verified on 63.0.3231.0 Canary on iPhone6+ iOS 11.0. The above is not fixed.Dismiss icon is still missing when navigating from Quick actions.
https://drive.google.com/a/google.com/file/d/0B6GVWQnhaMClcXlBN1lCb19Ud0U/view?usp=sharing

In the video shown here, the dismiss icon is already missing prior to navigating with quick actions. Please note how you ended up in this state, as that's where the issue is. (My fix makes it so that the omnibox is left as it is when re-opening chrome with a command that would focus the omnibox, so it makes sense that the icon would continue to be missing if it starts out that way).

Issue can be reproduced on 63.0.3231.0 canary tested on iPhone7+(11.0.1).

Updating the new video.
https://drive.google.com/a/google.com/file/d/0B--UpU2GW2EpUHBJOE11a1JkN0U/view?usp=sharing

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e3ada24fbeaa533f6c460ad8b78f7df2fc2bd24e

commit e3ada24fbeaa533f6c460ad8b78f7df2fc2bd24e
Author: Elodie Banel <lod@google.com>
Date: Wed Oct 04 09:54:50 2017

Fix dismissOmnibox parameter in user_activity_handler code path.

In testing I had missed this startup code path, so the omnibox dismiss
icon was still missing in certain cases.

Bug:  749030 
Change-Id: I94b6567bb19d474d24a68e4382f4a4ab82bf6a32
Reviewed-on: https://chromium-review.googlesource.com/700000
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Elodie Banel <lod@chromium.org>
Cr-Commit-Position: refs/heads/master@{#506352}
[modify] https://crrev.com/e3ada24fbeaa533f6c460ad8b78f7df2fc2bd24e/ios/chrome/app/application_delegate/user_activity_handler.mm

Thank you, pmadalla. This should be fixed now.

This bug requires manual review: Less than 8 days to go before AppStore submit on M62
Please contact the milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), bhthompson@(ChromeOS), abdulsyed@(Desktop)

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

Verified the issue on the build 63.0.3234.0 canary tested on iPhone7+(11.0.1).
Dismiss icon in omnibox is displayed on opening a newtab from chrome extensions, works fine.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f96076fcc8c7ec09ec4d4aac68b111f37ff9884a

commit f96076fcc8c7ec09ec4d4aac68b111f37ff9884a
Author: Elodie Banel <lod@google.com>
Date: Tue Oct 10 08:56:33 2017

Fix dismissOmnibox parameter in user_activity_handler code path.

In testing I had missed this startup code path, so the omnibox dismiss
icon was still missing in certain cases.

Bug:  749030 
Change-Id: I94b6567bb19d474d24a68e4382f4a4ab82bf6a32
Reviewed-on: https://chromium-review.googlesource.com/700000
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Elodie Banel <lod@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#506352}(cherry picked from commit e3ada24fbeaa533f6c460ad8b78f7df2fc2bd24e)
Reviewed-on: https://chromium-review.googlesource.com/708554
Reviewed-by: Elodie Banel <lod@chromium.org>
Cr-Commit-Position: refs/branch-heads/3202@{#633}
Cr-Branched-From: fa6a5d87adff761bc16afc5498c3f5944c1daa68-refs/heads/master@{#499098}
[modify] https://crrev.com/f96076fcc8c7ec09ec4d4aac68b111f37ff9884a/ios/chrome/app/application_delegate/user_activity_handler.mm

Verified the issue on the build 62.0.3202.52 beta tested on iPhone7+(11.0.1),iPhone8(11.0.1),iPhone5(10.3.3).
Dismiss icon in omnibox is displayed on opening a newtab from chrome extensions, works fine.