
Also replaced the duplicated EMPTY track group array with the one already defined in TrackGroupArray. ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=175670266
Also replaced the duplicated EMPTY track group array with the one already defined in TrackGroupArray. ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=175670266