Configure was transitioning the swapchain images from undefined to
present layout but this was already happening because TextureVk starts
with a mLastUsage of None that will force a transition from undefined
when used.
Also introduce an internal texture usage bit kPresentTextureUsage to
prepare for the eventual remove of wgpu::TextureUsage::Present when
old swapchains are removed.
Bug: dawn:269
Change-Id: I57d26f18e34cacd5d91419a45787b2ece9558846
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/20881
Reviewed-by: Stephen White <senorblanco@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>