I would like to handle this issue. :)

Hi jdragon.bae@! Sure, feel free to go ahead and try to tackle this issue :) I marked this bug assigned to you. When you publish your change in Gerrit, make sure to reference this bug and include vabr@ and me as your reviewers.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/88f4fec375abc6413c4157415119cadff2675c66

commit 88f4fec375abc6413c4157415119cadff2675c66
Author: Jdragon <jdragon.bae@gmail.com>
Date: Thu Oct 04 06:13:21 2018

Skip password_manager_util in credential unittests

This patch means skip password_manager_utils
by creating one instance of that cleaner
and using a mock CredentialsCleaner::Observer.

Bug:  889983 
Change-Id: I246133064540887c06104c85c97fad1ba7b7aed9
Reviewed-on: https://chromium-review.googlesource.com/c/1257495
Reviewed-by: Vaclav Brozek <vabr@chromium.org>
Commit-Queue: Jaeyong Bae <jdragon.bae@gmail.com>
Cr-Commit-Position: refs/heads/master@{#596521}
[modify] https://crrev.com/88f4fec375abc6413c4157415119cadff2675c66/components/password_manager/core/browser/blacklisted_duplicates_cleaner_unittest.cc
[modify] https://crrev.com/88f4fec375abc6413c4157415119cadff2675c66/components/password_manager/core/browser/invalid_realm_credential_cleaner_unittest.cc

Thanks for fixing this!