Use n1-highcpu-64 machines for Windows Builds.

Bug: skia:7409
Change-Id: I6c9d86af147f5234a0484e43e053ce1758cb312d
Reviewed-on: https://skia-review.googlesource.com/85400
Reviewed-by: Mike Klein <mtklein@chromium.org>
Reviewed-by: Eric Boren <borenet@google.com>
Commit-Queue: Ben Wagner <benjaminwagner@google.com>
2 files changed