makeVulkan
fun makeVulkan(width: Int, height: Int, textureInfo: VulkanTextureInfo, imageLayout: Int, queueFamilyIndex: Int, imagePtr: NativePointer): BackendTexture
Creates a Graphite backend texture that wraps an existing VkImage.
The image memory is assumed to be managed by the client (or by the driver, as is the case for swapchain images), so no allocation info is passed to Skia.