eliminate SK_BUILD_FOR_WIN32

SK_BUILD_FOR_WIN and SK_BUILD_FOR_WIN32 have long meant the same thing.

Chrome fix is https://chromium-review.googlesource.com/c/chromium/src/+/884007

Change-Id: I0e907b1bcd2a358eabf776f414fd3aeb3c689561
Reviewed-on: https://skia-review.googlesource.com/99340
Reviewed-by: Mike Reed <reed@google.com>
49 files changed