Improve logging and add DCHECKs in codec database.

BUG=
R=mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/47719004

Cr-Original-Commit-Position: refs/heads/master@{#8842}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 0b52cebd28c816cab1eed03b7b9baa7272d2ba1e
2 files changed