All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=758595

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=c18a640962f3e24eb440abf54380d76c36a37bb49af41157913b316d92b31d6d


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

chromium-rel-win8-dual

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8970368661542338176

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

Suspected Commit
  Author : Nico Weber
  Commit : 7cd2f6bd73c6a9c6200704e995b18ebb3168ead6
  Date   : Sat Aug 19 04:23:54 2017
  Subject: win: Turn off clang-by-default again for now.

Bisect Details
  Configuration: win_8_perf_bisect
  Benchmark    : smoothness.tough_animation_cases
  Metric       : frame_times/overlay_background_color_css_transitions.html
  Change       : 25.45% | 132.423873772 -> 166.126845945

Revision             Result                  N
chromium@495787      132.424 +- 5.1602       6      good
chromium@495798      130.613 +- 3.31941      6      good
chromium@495801      129.004 +- 7.15924      6      good
chromium@495802      168.909 +- 3.9969       6      bad       <--
chromium@495803      169.43 +- 12.2619       6      bad
chromium@495808      166.127 +- 6.86481      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=overlay.background.color.css.transitions.html smoothness.tough_animation_cases

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8970368661542338176


For feedback, file a bug with component Speed>Bisection

 Issue 758594  has been merged into this issue.