* Make ProcessFrame return void.
* Make |encode_callback_| and |decode_callback_| direct members.
* Remove ::EncodedFrameSize() and ::EncodedFrameType()
* Remove unused |timestamp| member from FrameInfo.
* Reorder printf output from PrintCodecSettings.
* Make some member functions const.
BUG=webrtc:6634
Review-Url: https://codereview.webrtc.org/2998063002
Cr-Commit-Position: refs/heads/master@{#19421}