Move SK_WINUWP into skia_private.

The skia_winuwp config is removed and the content moved into the
skia_private config. This allows for SK_WINUWP to be set more
uniformally. The skia_winuwp config was only used in the optional
template since all the code which required SK_WINUWP to be set correctly
was in the sources of an optional target. The optional targets already
have skia_private config available (through skia_library_configs).

Change-Id: I7f934cac0f68fb69cbac39ae76d5b45e4a47eab3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/371483
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
1 file changed