GitLab

Adds title field attribute to that will allow InfoBar overlay in iOS
code to set both a title and subtitle in its message. This is required
in some instances where the required notification provides a title
as will be the case for sign-in account notifications.

Approved UX Design:
https://docs.google.com/presentation/d/1tgAFQVKEUd-NcxyJhs6ZNqEu9j4QvX3-S_1wH9sU55k/edit#slide=id.ga6d0dd7c46_0_709

Bug: 1145592
Change-Id: Ic10bc8ed01f93f471e39c558dc09295d4257308c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2521619
Commit-Queue: Nohemi Fernandez <fernandex@chromium.org>
Reviewed-by: Chris Lu <thegreenfrog@chromium.org>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825383}