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=tina.legrand@webrtc.org
Bug: None
Change-Id: Iea6f04db7c1f92fe9da2c855bb60ad2f70c371d3
Reviewed-on: https://webrtc-review.googlesource.com/23615
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Oskar Sundbom <ossu@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20915}