srahim@: can you advice on the strings we should use in those cases?
The string displayed in the help are:
- "Press and hold for more tab options" (issue 849621), displayed pointing to the TabGrid button (which can be at the top or at the bottom of the screen).
- "Search bar is now easier to reach" (issue 830635) displayed pointing to the search button, in the bottom toolbar.

Please assign back to me after

Maybe for the second, we should say something like:
"Some buttons have moved to the bottom of the screen, like forward, back and tab switching"

That way, VoiceOver users know that they have to keep scrolling to get to these buttons.

Two thoughts:
1) IIRC for Android, we prefaced the in-product help announcement with "Chrome tip" to provide context.
2) VoiceOver announces the TabGrid button as "Show Tabs [Number of tabs]". So ideally the strings referring to that button use the same language. 

Proposed strings (riffing on the strings mentioned in c#1 and c#2 for parity with the visual UI):

- "Chrome tip. For more tab options, press and hold the Show Tabs button in the toolbar, which is at the bottom or top of your screen"

The search one is a little awkward, but here's a try:
- "Chrome tip. Some buttons are now at the bottom of your screen, like Back, Forward, and Search."

Thanks srahim@ 
Just to clarify, these strings that start with "Chrome tip" are meant for voiceover announcements, while the written strings in in-product help are different and don't include the preface of "Chrome tip." Right?

Yes, correct; this bug is only for the a11y strings. The visual design conveys that the message is a tip (it's blue, so it looks different than the rest of the UI; it's a pop-up; it points to a specific part of the UI). The screenreader/VoiceOver experience doesn't have those visual cues, so we add a verbal cue in the form of "Chrome tip".

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2402e6e7c0e6c9e13aa1f9c6fb07943870936901

commit 2402e6e7c0e6c9e13aa1f9c6fb07943870936901
Author: Gauthier Ambard <gambard@chromium.org>
Date: Tue Jul 31 07:51:17 2018

Add announcements for the bubble tips

This CL adds announcements to be read with VoiceOver for the in product
helps.

Bug:  866936 
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Ie89fa1b2b0179a8070351c2ce926ac18158ebdef
Reviewed-on: https://chromium-review.googlesource.com/1154536
Reviewed-by: edchin <edchin@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579336}
[modify] https://crrev.com/2402e6e7c0e6c9e13aa1f9c6fb07943870936901/ios/chrome/app/strings/ios_chromium_strings.grd
[modify] https://crrev.com/2402e6e7c0e6c9e13aa1f9c6fb07943870936901/ios/chrome/app/strings/ios_google_chrome_strings.grd
[modify] https://crrev.com/2402e6e7c0e6c9e13aa1f9c6fb07943870936901/ios/chrome/browser/ui/bubble/bubble_presenter.mm
[modify] https://crrev.com/2402e6e7c0e6c9e13aa1f9c6fb07943870936901/ios/chrome/browser/ui/bubble/bubble_view_controller_presenter.h
[modify] https://crrev.com/2402e6e7c0e6c9e13aa1f9c6fb07943870936901/ios/chrome/browser/ui/bubble/bubble_view_controller_presenter.mm

In some cases the tip is cancelled by elements stealing VoiceOver focus (at the end of the animation). I am adding a delay to prevent this.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1e910c7f7397ace03f42e1e39663de5ec93a9a58

commit 1e910c7f7397ace03f42e1e39663de5ec93a9a58
Author: Gauthier Ambard <gambard@chromium.org>
Date: Wed Aug 01 19:10:45 2018

[iOS] Accessibility adjustments

This CL adds a delay for the voice over announcement of the InProduct
Help tips. This delay is added to prevent the announcement to be
cancelled by the element being focused, when the tab is presented.
It also adds an accessibility label to the empty space where the omnibox
should be if the toolbar was visible.

Bug:  866936 
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Ia75dd56772203e39b8d0bf1e94bef9cfacd87fdd
Reviewed-on: https://chromium-review.googlesource.com/1158236
Commit-Queue: edchin <edchin@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579886}
[modify] https://crrev.com/1e910c7f7397ace03f42e1e39663de5ec93a9a58/ios/chrome/browser/ui/bubble/bubble_view_controller_presenter.mm
[modify] https://crrev.com/1e910c7f7397ace03f42e1e39663de5ec93a9a58/ios/chrome/browser/ui/content_suggestions/content_suggestions_header_view_controller.mm

Verified on Canary.
+kariahda@ for merge approval. Both CLs need to be merged.

This bug requires manual review: There is .grd file changes and we are only 32 days from stable.
Please contact the milestone owner if you have questions.
Owners: amineer@(Android), kariahda@(iOS), cindyb@(ChromeOS), govind@(Desktop)

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

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a9438c2a3370a27134b51e2692c1b67da8d6ef07

commit a9438c2a3370a27134b51e2692c1b67da8d6ef07
Author: Elodie Banel <lod@chromium.org>
Date: Thu Aug 02 09:37:55 2018

Revert "[iOS] Accessibility adjustments"

This reverts commit 1e910c7f7397ace03f42e1e39663de5ec93a9a58.

Reason for revert: Breaks ios_internal_chrome_external_url_egtests (see example failure here https://logs.chromium.org/v/?s=chrome%2Fbb%2Finternal.bling.main%2Fipad10-simulator%2F13834%2F%2B%2Frecipes%2Fsteps%2Fios_internal_chrome_external_url_egtests__iPad_Retina_iOS_10.2__on_Mac%2F0%2Flogs%2FExternalURLGWSTestCase__x2f_testGWSHistoryAutosuggest%2F0 )

Original change's description:
> [iOS] Accessibility adjustments
> 
> This CL adds a delay for the voice over announcement of the InProduct
> Help tips. This delay is added to prevent the announcement to be
> cancelled by the element being focused, when the tab is presented.
> It also adds an accessibility label to the empty space where the omnibox
> should be if the toolbar was visible.
> 
> Bug:  866936 
> Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
> Change-Id: Ia75dd56772203e39b8d0bf1e94bef9cfacd87fdd
> Reviewed-on: https://chromium-review.googlesource.com/1158236
> Commit-Queue: edchin <edchin@chromium.org>
> Reviewed-by: edchin <edchin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#579886}

TBR=edchin@chromium.org,gambard@chromium.org

Change-Id: I172a7e67b8ef5d4b4a2008f0f95ef99d7c0152e2
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug:  866936 
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Reviewed-on: https://chromium-review.googlesource.com/1160281
Reviewed-by: Elodie Banel <lod@chromium.org>
Commit-Queue: Elodie Banel <lod@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580121}
[modify] https://crrev.com/a9438c2a3370a27134b51e2692c1b67da8d6ef07/ios/chrome/browser/ui/bubble/bubble_view_controller_presenter.mm
[modify] https://crrev.com/a9438c2a3370a27134b51e2692c1b67da8d6ef07/ios/chrome/browser/ui/content_suggestions/content_suggestions_header_view_controller.mm

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/chrome/ios_internal.git/+/1a7a52cbfbd0b4324d2a68886244dfdfc85ecdf3

commit 1a7a52cbfbd0b4324d2a68886244dfdfc85ecdf3
Author: Gauthier Ambard <gambard@google.com>
Date: Thu Aug 02 14:15:02 2018

The fix was reverted to a failing test downstream. I am currently relanding the fix as is.
I am requesting merge request for the fix and the downstream test fix.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6f07bb6f5a1745bfe3412f30927cbc0578777d87

commit 6f07bb6f5a1745bfe3412f30927cbc0578777d87
Author: Gauthier Ambard <gambard@chromium.org>
Date: Thu Aug 02 15:43:19 2018

Reland "[iOS] Accessibility adjustments"

This is a reland of 1e910c7f7397ace03f42e1e39663de5ec93a9a58.
It is safe to reland as a fix for the test has landed downstream.

Original change's description:
> [iOS] Accessibility adjustments
>
> This CL adds a delay for the voice over announcement of the InProduct
> Help tips. This delay is added to prevent the announcement to be
> cancelled by the element being focused, when the tab is presented.
> It also adds an accessibility label to the empty space where the omnibox
> should be if the toolbar was visible.
>
> Bug:  866936 
> Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
> Change-Id: Ia75dd56772203e39b8d0bf1e94bef9cfacd87fdd
> Reviewed-on: https://chromium-review.googlesource.com/1158236
> Commit-Queue: edchin <edchin@chromium.org>
> Reviewed-by: edchin <edchin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#579886}

TBR: edchin@chromium.org
Bug:  866936 
Change-Id: I0c96e39827d4fb8f815664b10414314cad42a20c
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Reviewed-on: https://chromium-review.googlesource.com/1160661
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580203}
[modify] https://crrev.com/6f07bb6f5a1745bfe3412f30927cbc0578777d87/ios/chrome/browser/ui/bubble/bubble_view_controller_presenter.mm
[modify] https://crrev.com/6f07bb6f5a1745bfe3412f30927cbc0578777d87/ios/chrome/browser/ui/content_suggestions/content_suggestions_header_view_controller.mm

Approved.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c980ef9ae4ae20f430376fcba63868968e405fbc

commit c980ef9ae4ae20f430376fcba63868968e405fbc
Author: Gauthier Ambard <gambard@chromium.org>
Date: Thu Aug 02 18:23:56 2018

Add announcements for the bubble tips

This CL adds announcements to be read with VoiceOver for the in product
helps.

Bug:  866936 
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Ie89fa1b2b0179a8070351c2ce926ac18158ebdef
Reviewed-on: https://chromium-review.googlesource.com/1154536
Reviewed-by: edchin <edchin@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#579336}(cherry picked from commit 2402e6e7c0e6c9e13aa1f9c6fb07943870936901)
Reviewed-on: https://chromium-review.googlesource.com/1161061
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/branch-heads/3497@{#345}
Cr-Branched-From: 271eaf50594eb818c9295dc78d364aea18c82ea8-refs/heads/master@{#576753}
[modify] https://crrev.com/c980ef9ae4ae20f430376fcba63868968e405fbc/ios/chrome/app/strings/ios_chromium_strings.grd
[modify] https://crrev.com/c980ef9ae4ae20f430376fcba63868968e405fbc/ios/chrome/app/strings/ios_google_chrome_strings.grd
[modify] https://crrev.com/c980ef9ae4ae20f430376fcba63868968e405fbc/ios/chrome/browser/ui/bubble/bubble_presenter.mm
[modify] https://crrev.com/c980ef9ae4ae20f430376fcba63868968e405fbc/ios/chrome/browser/ui/bubble/bubble_view_controller_presenter.h
[modify] https://crrev.com/c980ef9ae4ae20f430376fcba63868968e405fbc/ios/chrome/browser/ui/bubble/bubble_view_controller_presenter.mm

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/23a3f665bf9dcf28746cf957e2871fab0a20dce9

commit 23a3f665bf9dcf28746cf957e2871fab0a20dce9
Author: Gauthier Ambard <gambard@chromium.org>
Date: Thu Aug 02 18:24:36 2018

[iOS] Accessibility adjustments

This CL adds a delay for the voice over announcement of the InProduct
Help tips. This delay is added to prevent the announcement to be
cancelled by the element being focused, when the tab is presented.
It also adds an accessibility label to the empty space where the omnibox
should be if the toolbar was visible.

Bug:  866936 
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Ia75dd56772203e39b8d0bf1e94bef9cfacd87fdd
Reviewed-on: https://chromium-review.googlesource.com/1158236
Commit-Queue: edchin <edchin@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#579886}(cherry picked from commit 1e910c7f7397ace03f42e1e39663de5ec93a9a58)
Reviewed-on: https://chromium-review.googlesource.com/1160505
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/branch-heads/3497@{#346}
Cr-Branched-From: 271eaf50594eb818c9295dc78d364aea18c82ea8-refs/heads/master@{#576753}
[modify] https://crrev.com/23a3f665bf9dcf28746cf957e2871fab0a20dce9/ios/chrome/browser/ui/bubble/bubble_view_controller_presenter.mm
[modify] https://crrev.com/23a3f665bf9dcf28746cf957e2871fab0a20dce9/ios/chrome/browser/ui/content_suggestions/content_suggestions_header_view_controller.mm

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/chrome/ios_internal.git/+/45b1a438642ec2191ab9e0477171d7d16e8e34e2

commit 45b1a438642ec2191ab9e0477171d7d16e8e34e2
Author: Gauthier Ambard <gambard@google.com>
Date: Fri Aug 03 07:06:21 2018