GitLab

Update StatisticsProvider to drop pairs received from
crossystem that have "(error)" values. NameValuePairsParser
ignores duplicate values, so we should get rid of these so
they don't prevent us from saving real values later.

Also downgrade a "Statistics loaded after waiting ___ ms"
LOG(WARNING) to VLOG(1), since this seems to be the common
case on a caroline ToT device and it just ends up cluttering
the logs.

Bug: 844258
Change-Id: Idf869617a03992e51a720359b4ebfdac91dec6e9
Reviewed-on: https://chromium-review.googlesource.com/1072706Reviewed-by: Thiemo Nagel <tnagel@chromium.org>
Commit-Queue: Dan Erat <derat@chromium.org>
Cr-Commit-Position: refs/heads/master@{#563053}