Vulkan backend was missing dependency on NativeWindow.

Bug: angleproject:2314

Change-Id: I66675af6f885b57bdb0524a0626dfec0256a21d3
Reviewed-on: https://chromium-review.googlesource.com/c/1354100Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>