This makes it less manual code and less error prone to
add new callbacks to the wire.
Bug: dawn:384
Change-Id: I8547af2dba8289d1badd41e53dd732c776fb5d06
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/35600
Reviewed-by: Jiawei Shao <jiawei.shao@intel.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Austin Eng <enga@chromium.org>