FALLBACK_SOFTWARE is now treated as a critical error and results in immediate fallback to software coding if available. If ERROR is returned, codec reset is attempted. If that fails, software fallback is used. Bug: b/73498933 Change-Id: I7fe163efd09e6f27c72491e9595954ddc59b1448 Reviewed-on: https://webrtc-review.googlesource.com/54901 Reviewed-by: Alex Glaznev <glaznev@webrtc.org> Commit-Queue: Sami Kalliomäki <sakal@webrtc.org> Cr-Commit-Position: refs/heads/master@{#22169}