This CL replaces CHECKs and crashes with DCHECKs and default values. Bug: webrtc:9535 Change-Id: Ib4b16421699c633d0e9ef140189861c8179450f4 Reviewed-on: https://webrtc-review.googlesource.com/c/105003 Reviewed-by: Alex Loiko <aleloi@webrtc.org> Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org> Commit-Queue: Sam Zackrisson <saza@webrtc.org> Cr-Commit-Position: refs/heads/master@{#25111}