The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d70b0b01ab6fc26dd32ffceabdccce3dd6d2b0f0

commit d70b0b01ab6fc26dd32ffceabdccce3dd6d2b0f0
Author: Chris Blume <cblume@chromium.org>
Date: Tue Oct 16 21:31:13 2018

Get Vulkan building on Windows

This CL adds support for Vulkan on windows but disables it in builds.
This makes it easy to enable and test.

BUG=850724

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: I8396b2f59133df5d72d1086cf22e154dba0bb15e
Reviewed-on: https://chromium-review.googlesource.com/c/1270098
Commit-Queue: Chris Blume <cblume@chromium.org>
Reviewed-by: Eric Karl <ericrk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600127}
[modify] https://crrev.com/d70b0b01ab6fc26dd32ffceabdccce3dd6d2b0f0/gpu/vulkan/features.gni
[modify] https://crrev.com/d70b0b01ab6fc26dd32ffceabdccce3dd6d2b0f0/gpu/vulkan/init/BUILD.gn
[modify] https://crrev.com/d70b0b01ab6fc26dd32ffceabdccce3dd6d2b0f0/gpu/vulkan/init/vulkan_factory.cc
[add] https://crrev.com/d70b0b01ab6fc26dd32ffceabdccce3dd6d2b0f0/gpu/vulkan/win32/BUILD.gn
[add] https://crrev.com/d70b0b01ab6fc26dd32ffceabdccce3dd6d2b0f0/gpu/vulkan/win32/vulkan_implementation_win32.cc
[add] https://crrev.com/d70b0b01ab6fc26dd32ffceabdccce3dd6d2b0f0/gpu/vulkan/win32/vulkan_implementation_win32.h