GitLab

Use std::unique_ptr instead of deprecated linked_ptr

Bug: 556939
Change-Id: Ifb89741b5815b388961a67aebf6d1f7cf07d7b7d
Reviewed-on: https://chromium-review.googlesource.com/1040325Reviewed-by: Mikel Astiz <mastiz@chromium.org>
Commit-Queue: Sungguk Lim <limasdf@gmail.com>
Cr-Commit-Position: refs/heads/master@{#556019}