Merge "Vulkan: Ensure swapchain gets enough images for MAILBOX." into qt-dev

    }

    uint32_t min_undequeued_buffers = static_cast<uint32_t>(query_value);

    uint32_t num_images =

        (create_info->minImageCount - 1) + min_undequeued_buffers;

        (swap_interval ? create_info->minImageCount

                       : std::max(3u, create_info->minImageCount)) -

        1 + min_undequeued_buffers;

    // Lower layer insists that we have at least two buffers. This is wasteful

    // and we'd like to relax it in the shared case, but not all the pieces are