All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=748278

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=8f549f66db45336b47e716b9e6b2d009c7aa2d4fe733822cbad4ea52d33d015e


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

chromium-rel-mac11

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8973144901447312208

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

Suspected Commit
  Author : Michael Nordman
  Commit : 20b379ba1a5ce5ae093386c7ffe764d63246b66f
  Date   : Fri Jul 21 18:08:09 2017
  Subject: Revert "Reland "Reimplement base::WaitableEvent with a kqueue on Mac.""

Bisect Details
  Configuration: mac_10_11_perf_bisect
  Benchmark    : media_perftests
  Metric       : demuxer_bench/sfx.mp3
  Change       : 12.55% | 1674.11750184 -> 1464.02826206

Revision             Result                  N
chromium@488676      1674.12 +- 64.4984      6      good
chromium@488702      1680.26 +- 71.3413      6      good
chromium@488704      1668.23 +- 75.5075      6      good
chromium@488705      1679.39 +- 73.2455      6      good
chromium@488706      1446.51 +- 82.2454      6      bad       <--
chromium@488709      1428.3 +- 83.2494       6      bad
chromium@488715      1427.72 +- 45.9848      6      bad
chromium@488727      1427.61 +- 34.75        6      bad
chromium@488777      1464.03 +- 85.2728      6      bad

To Run This Test
  ./src/out/Release/media_perftests --single-process-tests

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8973144901447312208


For feedback, file a bug with component Speed>Bisection