Delete unused member variable VideoTrackSource::options_.
Delete unused member variable VideoTrackSource::options_.

Bug: None
Change-Id: I1aa4a29aa83faaec22bfe811044439bbdc9b8b15
Reviewed-on: https://webrtc-review.googlesource.com/78400
Reviewed-by: Per Kjellander <ec3efbb37602a1ca89f5fcf018e3a9e25086611a@webrtc.org>
Commit-Queue: Niels Moller <0057859e47d61d90529d0f66d9ef692cefedb46a@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#23365}
TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc