Add encoded_timestamp to AudioEncoder base class
Add encoded_timestamp to AudioEncoder base class

BUG=3926
TBR=kwiberg@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/24029004

Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 264e66f7a5edc1b72adbb13962d1ec9b1c6f1805

sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc