Working on this...

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b2020d34fda4ac11e17f89dddc2427e6afc816aa

commit b2020d34fda4ac11e17f89dddc2427e6afc816aa
Author: Sergio Villar Senin <svillar@igalia.com>
Date: Wed Oct 17 17:04:37 2018

Convert chrome_feedback_private_delegate.cc to IdentityManager

It's currently using the SigninManager to retrieve the primary
(authenticated) account's email. Migrated to the IdentityManager API
so it could eventually make use of the identity service.

Bug:  890774 
Change-Id: I92e1ddafaa8270a5fdd4b154de85a4be1f8a4168
Reviewed-on: https://chromium-review.googlesource.com/c/1286138
Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Sergio Villar <svillar@igalia.com>
Cr-Commit-Position: refs/heads/master@{#600439}
[modify] https://crrev.com/b2020d34fda4ac11e17f89dddc2427e6afc816aa/chrome/browser/extensions/BUILD.gn
[modify] https://crrev.com/b2020d34fda4ac11e17f89dddc2427e6afc816aa/chrome/browser/extensions/api/feedback_private/chrome_feedback_private_delegate.cc

Closing