The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c15309b1e00906edd9e60f03c1cbed736f5daed9

commit c15309b1e00906edd9e60f03c1cbed736f5daed9
Author: Yuke Liao <liaoyuke@chromium.org>
Date: Fri Jul 28 17:11:50 2017

Fix back button for show case on iOS 11.

The original matcher fails on IOS 11 because it depends on a private
class and that class is not used anymore. Find a more robust solution
that is consistent across different iOS versions.

Bug:  750185 
Change-Id: I54d54452a6dbf721401d3eaa14a010cfcd129d81
Reviewed-on: https://chromium-review.googlesource.com/591911
Commit-Queue: Yuke Liao <liaoyuke@chromium.org>
Reviewed-by: Ed Chin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#490436}
[modify] https://crrev.com/c15309b1e00906edd9e60f03c1cbed736f5daed9/ios/showcase/core/showcase_egtest.mm
[modify] https://crrev.com/c15309b1e00906edd9e60f03c1cbed736f5daed9/ios/showcase/core/showcase_view_controller.mm
[modify] https://crrev.com/c15309b1e00906edd9e60f03c1cbed736f5daed9/ios/showcase/test/showcase_eg_utils.mm

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3c3b814be7218c3985d1eb2b36cc6ca75fb33d86

commit 3c3b814be7218c3985d1eb2b36cc6ca75fb33d86
Author: Yuke Liao <liaoyuke@chromium.org>
Date: Fri Jul 28 20:32:49 2017

Revert "Fix back button for show case on iOS 11."

This reverts commit c15309b1e00906edd9e60f03c1cbed736f5daed9.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Fix back button for show case on iOS 11.
> 
> The original matcher fails on IOS 11 because it depends on a private
> class and that class is not used anymore. Find a more robust solution
> that is consistent across different iOS versions.
> 
> Bug:  750185 
> Change-Id: I54d54452a6dbf721401d3eaa14a010cfcd129d81
> Reviewed-on: https://chromium-review.googlesource.com/591911
> Commit-Queue: Yuke Liao <liaoyuke@chromium.org>
> Reviewed-by: Ed Chin <edchin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#490436}

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

Change-Id: I5d47eb233739f08b5c5072d1636ec027f6f8a900
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug:  750185 
Reviewed-on: https://chromium-review.googlesource.com/592114
Reviewed-by: Yuke Liao <liaoyuke@chromium.org>
Commit-Queue: Yuke Liao <liaoyuke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#490500}
[modify] https://crrev.com/3c3b814be7218c3985d1eb2b36cc6ca75fb33d86/ios/showcase/core/showcase_egtest.mm
[modify] https://crrev.com/3c3b814be7218c3985d1eb2b36cc6ca75fb33d86/ios/showcase/core/showcase_view_controller.mm
[modify] https://crrev.com/3c3b814be7218c3985d1eb2b36cc6ca75fb33d86/ios/showcase/test/showcase_eg_utils.mm

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ff4c4e510cafd80618d19e0bb6893a70de8d8215

commit ff4c4e510cafd80618d19e0bb6893a70de8d8215
Author: Yuke Liao <liaoyuke@chromium.org>
Date: Fri Jul 28 22:37:54 2017

Reland "Fix back button for show case on iOS 11."

Original change's description:
> Fix back button for show case on iOS 11.
>
> The original matcher fails on IOS 11 because it depends on a private
> class and that class is not used anymore. Find a more robust solution
> that is consistent across different iOS versions.
>

Bug:  750185 
Change-Id: I040fa9e96b1a01b0eb2a53c61b77571c2fb65109
Reviewed-on: https://chromium-review.googlesource.com/592338
Reviewed-by: Ed Chin <edchin@chromium.org>
Commit-Queue: Yuke Liao <liaoyuke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#490527}
[modify] https://crrev.com/ff4c4e510cafd80618d19e0bb6893a70de8d8215/ios/showcase/core/showcase_egtest.mm
[modify] https://crrev.com/ff4c4e510cafd80618d19e0bb6893a70de8d8215/ios/showcase/core/showcase_view_controller.mm
[modify] https://crrev.com/ff4c4e510cafd80618d19e0bb6893a70de8d8215/ios/showcase/test/showcase_eg_utils.mm

The private class has been removed and a more robust matcher implemented.