All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=762215

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=71d84073857e6436009b12c96df12ee7ebb78b1f95b8a91483f3bf08fdd27b4f


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

chromium-rel-mac-retina
chromium-rel-mac11-air

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8969256195860640176

=== 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    : thread_times.tough_scrolling_cases
  Metric       : thread_total_all_cpu_time_per_frame/text_hover_20000_pixels_per_second
  Change       : 17.69% | 6.92885429423 -> 8.1546294786

Revision             Result                   N
chromium@497780      6.92885 +- 1.16708       9      good
chromium@497839      6.88248 +- 1.11392       9      good
chromium@497847      6.78329 +- 0.655764      6      good
chromium@497849      6.36385 +- 0.781601      6      good
chromium@497850      7.96921 +- 0.861772      6      bad       <--
chromium@497851      7.86549 +- 1.75723       9      bad
chromium@497854      7.66218 +- 1.65841       9      bad
chromium@497869      7.98164 +- 1.93448       9      bad
chromium@497898      8.15463 +- 1.24766       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 --story-filter=text.hover.20000.pixels.per.second thread_times.tough_scrolling_cases

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8969256195860640176


For feedback, file a bug with component Speed>Bisection