Add UWP support

Bug: skia:11102
Change-Id: I4ed9e44099cd780c5cdede3eb179c0e6a92d3ce5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/345219
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Chris Bracken <cbracken@google.com>
7 files changed