Prepare to remove StartRtcEventLog and StopRtcEventLog
Prepare to remove StartRtcEventLog and StopRtcEventLog

There are some internal projects that need to be updated before we remove StartRtcEventLog and StopRtcEventLog. In this CL we take away the pure-virtuality status of the functions. After landing this, we can fix the internal projects, then land https://webrtc-review.googlesource.com/c/src/+/6782.

TBR=stefan@webrtc.org

Bug: webrtc:8111
Change-Id: Ibe495a7e7d6bf8120b1a26f056bd1443031733bf
Reviewed-on: https://webrtc-review.googlesource.com/6980
Commit-Queue: Elad Alon <9d66cb9c3c57b29e6fc055a4405dac15e20e28ee@webrtc.org>
Reviewed-by: Karl Wiberg <2c708eb0a58047bf403399f50b3da33ffd2dd444@webrtc.org>
Reviewed-by: Ivo Creusen <ab68de427b265c46935558af10238a1ba5449aeb@webrtc.org>
Reviewed-by: Björn Terelius <efeae16329b3cb4ac5daf80d4bfda3344c027db3@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#20178}
ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc