Fix zlib build on UWP.

Uses the recommended check for WINAPI_FAMILY instead of outdated code.
If this patch sticks and is stable I'll submit a pull request to the
official zlib repo.

Bug: 1061905
Change-Id: I48fa8c884e8f78bbf890cc7f41ac610395833fff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2105453


Reviewed-by: Chris Blume <cblume@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#750639}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 1f7282c9d4f987f8e4300562688e722829e344e5