Remove SK_HAS_DWRITE_X defines.

While developing DirectWrite it was ncessary to support building with
older Windows SDKs which may not have certain headers. Now that the
minimum required Windows SDK is 8.1 (0x0603) we can remove these
difficult to use macros to simplify future development.

Change-Id: Ia780466b7c9b86198116c5974c43363f49a0ebac
Reviewed-on: https://skia-review.googlesource.com/9124
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
5 files changed