Change TrustedSourcesManager to return unique_ptr instead of raw pointer

Bug: 916176
Change-Id: I3418fdbceea18391bb09e957e4846accf1b28447
Reviewed-on: https://chromium-review.googlesource.com/c/1413072
Reviewed-by: Clark DuVall <cduvall@chromium.org>
Reviewed-by: Min Qin <qinmin@chromium.org>
Commit-Queue: Ayu Ishii <ayui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#626216}
5 files changed