Changes places where we explicitly construct an Optional to instead use
nullopt or the requisite value type only.
This CL was uploaded by git cl split.
R=magjed@webrtc.org
Bug: None
Change-Id: I78842b6bb8ae345bcb852feee3908fdaf955c664
Reviewed-on: https://webrtc-review.googlesource.com/23574
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Commit-Queue: Oskar Sundbom <ossu@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20956}