GitLab

This way UniquePtrMatcher can be used with containers that use a
deleter other than the default.

BUG=none
TEST=none

Change-Id: I4fcea47ea6d756f2ee68ebe94df70c5cd6e0bdc5
Reviewed-on: https://chromium-review.googlesource.com/1033692
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#554832}