All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=893848

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=cb38993c68c1c2561627fb99fc33fc349ce958141e2849279e0b7c6dc32e32d3


Bot(s) for this bug's original alert(s):

Android Nexus6 WebView Perf

rendering.mobile - Benchmark documentation link:
  https://bit.ly/rendering-benchmarks

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/12ee7b54e40000

📍 Found a significant difference after 1 commit.
https://pinpoint-dot-chromeperf.appspot.com/job/12ee7b54e40000

Roll src/third_party/catapult a7a24422d086..56216d7832a4 (1 commits) by chromium-autoroll@skia-public.iam.gserviceaccount.com
https://chromium.googlesource.com/chromium/src/+/84f9167ca06c316950a8f0eb12d6d55244769859
mean_pixels_approximated: 0 → 5.861e-05 (+5.861e-05)

Understanding performance regressions:
  http://g.co/ChromePerformanceRegressions

Benchmark documentation link:
  https://bit.ly/rendering-benchmarks

According to the CL description, I'm supposed to assign to sullivan@. (The TBR reviewer on the roll.)

 Issue 893851  has been merged into this issue.

Ehsan: The only CL in the roll is:
2018-10-05 chiniforooshan@chromium.org Telemetry: pixel approximated/checkerboarded

Can you take a look?

I think the zero to non-zero issue happens because the old code was rounding off values to 3 decimal digits:

https://chromium-review.googlesource.com/c/catapult/+/1262018/8/telemetry/telemetry/web_perf/metrics/rendering_stats.py#b272

The new TBMv2 version reports exact values. Given this, I think this is not a real regression and we can safely ignore (CCing @vmiura to reopen if rounding had a good reason that I ignored).