This removes the dependency on sstream which will reduce binary size. Bug: webrtc:8982 Change-Id: I153390f2d8baf3e15875c39d1f5027b3575bca31 Reviewed-on: https://webrtc-review.googlesource.com/c/115748 Reviewed-by: Henrik Boström <hbos@webrtc.org> Commit-Queue: Steve Anton <steveanton@webrtc.org> Cr-Commit-Position: refs/heads/master@{#26127}