tree a4ce5b4d8422a6103d0c93fb6ed8db3ccd1f1c22
parent dd090a6e8825093e7e5364ed49f16ba68f0fe54c
author shahan <shahan@google.com> 1519161630 -0800
committer Copybara-Service <copybara-piper@google.com> 1519161753 -0800

Adds ObjectCodecRegistry to {Des|S}erializationContext.

* AutoCodec now delegates to the registry.
* Adds getSuperclass logic for resolving a codec.
* Small cleanups for classes that break the registry.

TODO after this change:
* Explicit CODEC definitions are no longer needed and existing ones should be cleaned up.
* POLYMORPHIC is no longer be needed and should be cleaned up.

PiperOrigin-RevId: 186351845