All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=761217

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=ca44520e465d76d7072d9b48f0924a9f1868d616b652edbfb9dd28c30a28df4e


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

chromium-rel-mac-retina

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8969693089650273120

Let's keep this as 'Untriaged' to triage after the bisect job finishes.

=== BISECT JOB RESULTS ===
Perf regression found with culprit

Suspected Commit
  Author : Robert Sesek
  Commit : 5cd8eef498e28e1aacb9109645c001bbbfe1bc26
  Date   : Mon Aug 28 19:51:25 2017
  Subject: [Mac] A potential fix for WaitableEvent::WaitMany on macOS 10.11.

Bisect Details
  Configuration: mac_retina_perf_bisect
  Benchmark    : service_worker.service_worker_micro_benchmark
  Metric       : concurrent_10_response_90_percentile/concurrent_10_response_90_percentile
  Change       : 14.97% | 8.40166666667 -> 9.65916666667

Revision             Result                   N
chromium@497780      8.40167 +- 0.472158      6      good
chromium@497839      8.3725 +- 0.388314       6      good
chromium@497847      8.26 +- 0.251098         6      good
chromium@497849      8.26833 +- 0.391897      6      good
chromium@497850      9.66417 +- 0.153202      6      bad       <--
chromium@497851      9.7025 +- 0.250375       6      bad
chromium@497854      9.6775 +- 0.16893        6      bad
chromium@497869      9.74917 +- 0.102082      6      bad
chromium@497898      9.65917 +- 0.264898      6      bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=release --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests service_worker.service_worker_micro_benchmark

More information on addressing performance regressions:
  http://g.co/ChromePerformanceRegressions

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8969693089650273120


For feedback, file a bug with component Speed>Bisection