WinUWP cannot use the win task queue as post/peek message event loop
is not available. A replacement version written using stdlib compatible
with WinUWP is added as an alternative.
Change-Id: Ie9d6e6f11f395d1815d8f04633772a0c597ed30a
Bug: webrtc:10046
Reviewed-on: https://webrtc-review.googlesource.com/c/108520
Commit-Queue: Patrik Höglund <phoglund@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25781}
