This removes posix-only files from the default source set, forcing
them to be explictly included for the desired configurations.
Bug: chromium:812974
Change-Id: Ic4a1561f87395801ca4d3936a95a66fd4270c5ef
Reviewed-on: https://webrtc-review.googlesource.com/70564
Reviewed-by: Benjamin Wright <benwright@webrtc.org>
Commit-Queue: Fabrice de Gans-Riberi <fdegans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#22913}