Fixes for Angle to build with Windows GN.

Change-Id: I5af7a1305e5a190de5367ad940186edd6baee5bc
Reviewed-on: https://chromium-review.googlesource.com/227665
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
Fix fuzzy color check in ClearTest.

This test was failing on some systems because of overly stringent
color expectations.

BUG=angle:809

Change-Id: I817de315ff6de46fb87f8ed1c21e3bb62c133176
Reviewed-on: https://chromium-review.googlesource.com/225262
Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Fixes for Angle to build with Windows GN.

Change-Id: Id38c4b11dba31b2779efa7beade481cd50f3d935
Reviewed-on: https://chromium-review.googlesource.com/227692
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Tested-by: Shannon Woods <shannonwoods@chromium.org>