Removing...

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cb5cdde8d462450c083c4868e670c39c1bcf9c25

commit cb5cdde8d462450c083c4868e670c39c1bcf9c25
Author: Sergio Villar Senin <svillar@igalia.com>
Date: Tue Jan 22 16:59:50 2019

Remove SigninManager's leftover includes from EPK private API

There is no piece of code currently using the SigninManager so we can
safely remove them.

Bug:  920207 
Change-Id: If1235d83211c15c02f0fbafc5ec9b6a02125565e
Reviewed-on: https://chromium-review.googlesource.com/c/1407700
Reviewed-by: Mattias Nissler <mnissler@chromium.org>
Commit-Queue: Sergio Villar <svillar@igalia.com>
Cr-Commit-Position: refs/heads/master@{#624800}
[modify] https://crrev.com/cb5cdde8d462450c083c4868e670c39c1bcf9c25/chrome/browser/extensions/api/enterprise_platform_keys_private/enterprise_platform_keys_private_api.cc