All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=718055

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg8uHcuAkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg8qqsgAoM


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

android-webview-nexus5X

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8980602589597880464

=== BISECT JOB RESULTS ===
Bisect failed for unknown reasons

Please contact the team (see below) and report the error.


Bisect Details
  Configuration: android_webview_arm64_aosp_perf_bisect
  Benchmark    : system_health.common_mobile
  Metric       : story:power_avg/load_news/load_news_cnn


To Run This Test
  src/tools/perf/run_benchmark -v --browser=android-webview --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests --story-filter=load.news.cnn system_health.common_mobile

Debug Info
  https://chromeperf.appspot.com/buildbucket_job_status/8980602589597880464

Is this bisect wrong?
  https://chromeperf.appspot.com/bad_bisect?try_job_id=6367673438437376


| O O | Visit http://www.chromium.org/developers/speed-infra/perf-bug-faq
|  X  | for more information addressing perf regression bugs. For feedback,
| / \ | file a bug with component Speed>Bisection.  Thank you!

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8980431924342769984

 crbug.com/718928  for the android_webview_arm64_aosp_perf_bisect issues.

=== BISECT JOB RESULTS ===
Bisect failed for unknown reasons

Please contact the team (see below) and report the error.


Bisect Details
  Configuration: android_webview_arm64_aosp_perf_bisect
  Benchmark    : system_health.common_mobile
  Metric       : story:power_avg/load_news/load_news_cnn


To Run This Test
  src/tools/perf/run_benchmark -v --browser=android-webview --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests --story-filter=load.news.cnn system_health.common_mobile

Debug Info
  https://chromeperf.appspot.com/buildbucket_job_status/8980431924342769984

Is this bisect wrong?
  https://chromeperf.appspot.com/bad_bisect?try_job_id=6367673438437376


| O O | Visit http://www.chromium.org/developers/speed-infra/perf-bug-faq
|  X  | for more information addressing perf regression bugs. For feedback,
| / \ | file a bug with component Speed>Bisection.  Thank you!

I'm gonna go ahead and close this bug: this regression took place on the android-webview bots, which don't have any reference builds on them. The problem is that, without a reference build, it's really difficult to tell whether a movement on the power graph is due to an environmental change with the bot or an actual Chrome change. The dashboard logic automatically silences alerts that happened on the same revision on both the reference and tip of tree builds, but this obviously can't happen if there's no reference build.

I also went ahead and removed all webview BattOr-based power metrics from the perf sheriff's monitoring path, so you shouldn't get alerts like this in the future.