The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c7dcb6435895fd06565cbbef7413ba41b8f958dc

commit c7dcb6435895fd06565cbbef7413ba41b8f958dc
Author: Trent Apted <tapted@chromium.org>
Date: Tue Aug 07 00:42:22 2018

Delineate internal/external headers for ui/views/cocoa in views/BUILD.gn

Since  https://crbug.com/732993  was fixed, gn now supports a `friend`
property which the ui/views/ test targets can use. This means "internal"
headers only used (also) in tests no longer need to be repeated in test
targets inside views/BUILD.gn.

So, declare other targets in views/BUILD.gn as friends, remove those
repeated headers, and mark some things internal.

Start with ui/views/cocoa. Currently 3 headers are used in mac browser
code (for OS-specific fullscreen/native frame, and touchbar things).

Bug:  871123 
Change-Id: I5e5a260dd200f1bffc4f6fb8456d6e854fe19c52
Reviewed-on: https://chromium-review.googlesource.com/1163351
Commit-Queue: Trent Apted <tapted@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#581062}
[modify] https://crrev.com/c7dcb6435895fd06565cbbef7413ba41b8f958dc/chrome/browser/ui/cocoa/fullscreen/fullscreen_toolbar_controller_views.mm
[modify] https://crrev.com/c7dcb6435895fd06565cbbef7413ba41b8f958dc/ui/views/BUILD.gn

***UI Mass Triage***

Assuming the issue may be fixed since there is no activity, hence closing.If you feel this issue should still be addressed, please to reopen it or to file a new issue.