This callback is not being used by now, so we can just change it
without the deprecation dance.
Instead of the WasmModuleObject, it now receives the new
CompiledWasmModule wrapper which contains a shared pointer to the
NativeModule. This is all that's needed for serialization.

Some classes are pulled out of WasmModuleObject to allow reuse.

R=adamk@chromium.org, mstarzinger@chromium.org
CC=​bbudge@chromium.org

Bug: chromium:912031
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: Icedb64efa92e66bec45cf8742942a07ae22f59c8
Reviewed-on: https://chromium-review.googlesource.com/c/1363140Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58142}