When building certain Chromecast build flavors in component build mode, there are some link errors due to symbols not being exported. This CL fixes those issues. TBR: kwiberg@webrtc.org Bug: None Change-Id: I408f0a84b8ac4610cc6b5aa6ff58248ea82c9c66 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/161148 Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org> Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org> Cr-Commit-Position: refs/heads/master@{#29992}