All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=921187

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=ef4580d9ae484e4cefa1bf086b31e9920d21ed34af12e7fdad24114ba319e6a5


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

android-nexus5x-perf

system_health.common_mobile - Benchmark documentation link:
  https://bit.ly/system-health-benchmarks

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/14e23b63940000

📍 Found significant differences after each of 2 commits.
https://pinpoint-dot-chromeperf.appspot.com/job/14e23b63940000

Add OfflineTestUtil.java by harringtond@chromium.org
https://chromium.googlesource.com/chromium/src/+/110457cd42496fc3866e3f0992781d979c3435f7
timeToFirstPaint: 612.4 → No values

Revert "Add OfflineTestUtil.java" by harringtond@google.com
https://chromium.googlesource.com/chromium/src/+/bc04ada09cac882fa9dbeefffa8f65223723233e
timeToFirstPaint: No values → 699.6

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

Benchmark documentation link:
  https://bit.ly/system-health-benchmarks

I think this is just showing the test was broken and then unbroken.