increasing precision since summing up rounded values leads to a rounding error, in particular for small frames which take very little time to decode. BUG=webrtc:12526,webrtc:13756 Change-Id: I647c702808856a002c746ed9f115aa9bcaddc1f3 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/262810 Reviewed-by: Harald Alvestrand <hta@webrtc.org> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Commit-Queue: Philipp Hancke <philipp.hancke@googlemail.com> Cr-Commit-Position: refs/heads/main@{#37249}