This ensures that we don't break clients that can't handle negative values. Bug: webrtc:9598 Change-Id: I33c3933982577752eceb738d7e0bd2a6825d2249 Reviewed-on: https://webrtc-review.googlesource.com/93020 Commit-Queue: Sebastian Jansson <srte@webrtc.org> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Reviewed-by: Magnus Flodman <mflodman@webrtc.org> Cr-Commit-Position: refs/heads/master@{#24230}