Merge "Enable VK_KHR_swapchain for instances." into pi-dev

    for (uint32_t i = 0; i < ext_count; i++)

        FilterExtension(ext_names[i]);

    // Enable device extensions that contain physical-device commands, so that

    // vkGetInstanceProcAddr will return those physical-device commands.

    if (is_instance_) {

        hook_extensions_.set(ProcHook::KHR_swapchain);

    }

    ext_names = extension_filter_.names;

    ext_count = extension_filter_.name_count;