b77d6c4ef4
ProgressiveDownloader never implemented this properly, and we don't use it in DownloadManager/DownloadService, both of which use a polling model. A polling model is also what's used elsewhere, for example to query the current playback position. This is effectively doing the TODO in ProgressiveDownloader. ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=194214579