GitLab

Use `= default` for move constructors and assignment operators. This
cuts down a lot of bespoke code.

Bug: None
Change-Id: I818befbe8d70027f5d7b69da53ebc261028b113a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2511331
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823717}