These macros were causing conflicts when chrome redefines them and since
we don't rely on any specific windows versions, we can remove them.

BUG=angle:568

Change-Id: Ie6bf31d03cea07bf2a71ffa6d815dad2b4d204f8
Reviewed-on: https://chromium-review.googlesource.com/195364Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>