Upstream commit: https://webrtc.googlesource.com/src/+/2017c608e80a7bf52ee52908865f34192c69ce96 Move yield_policy.h to webrtc namespace Bug: webrtc:42232595 Change-Id: Ib36afd2909f7d6ed4e675251ea365f12f4be3761 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/378902 Commit-Queue: Harald Alvestrand <hta@webrtc.org> Reviewed-by: Harald Alvestrand <hta@webrtc.org> Auto-Submit: Evan Shrubsole <eshr@webrtc.org> Cr-Commit-Position: refs/heads/main@{#43993} Differential Revision: https://phabricator.services.mozilla.com/D244001