GitLab

This flag already exists and is used for this purpose on Android and
Desktop. This adds the flag to iOS.

Bug: 1048193
Change-Id: Ia50dbcc3994cc74592f821a3fbc6c3f74ff785a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2056776Reviewed-by: Ender <ender@google.com>
Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Commit-Queue: Robbie Gibson <rkgibson@google.com>
Cr-Commit-Position: refs/heads/master@{#742553}