Deploy self-built Vulkan validation layers instead of system installed
one. And it will reuse third_party/angle's Vulkan validation layers if
building with chromium.
Bug: dawn:150
Change-Id: I94e26f7a152fb2a1c39bcb102d60024f4d65eee6
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/11120
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>