win: Stop pulling cygwin and psyco.

psyco was used by gyp_chromium back in the gyp days. cygwin hasn't been
used in a few years as part of the build (and devs who want to use it
locally probably install it themselves already).

No intended behavior change.

Bug: 123026
Change-Id: Ia3fe83c2d98af406f01853d7402302f6e1512e63
Reviewed-on: https://chromium-review.googlesource.com/651490
Reviewed-by: Scott Graham <scottmg@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#500005}
2 files changed