All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=759032

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=2377efc97c1ff4fe09b4d2fbb2f71110f6a33206edb76d2909bff426e6fba91a


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

chromium-rel-win7-dual

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8970275335394238880

=== BISECT JOB RESULTS ===
NO Perf regression found

Bisect Details
  Configuration: win_perf_bisect
  Benchmark    : system_health.common_desktop
  Metric       : cpu_time_percentage_avg/browse_media/browse_media_tumblr

Revision             Result                   N
chromium@495791      1.0174 +- 0.348781       21      good
chromium@495808      1.07397 +- 0.223272      21      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=browse.media.tumblr system_health.common_desktop

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8970275335394238880


For feedback, file a bug with component Speed>Bisection

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8970262922476451008

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8970262915354283200

That's strange that it didn't repro; it's a pretty sharp increase on that bot. Kicked off a few bisects on other configs.

=== 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_x64_perf_bisect
  Benchmark    : system_health.common_desktop
  Metric       : cpu_time_percentage_avg/browse_social/browse_social_tumblr_infinite_scroll
  Change       : 7.47% | 0.262949653086 -> 0.282592424993

Revision             Result                      N
chromium@495545      0.26295 +- 0.00460473       6      good
chromium@495677      0.265262 +- 0.00771994      6      good
chromium@495743      0.266467 +- 0.00812202      6      good
chromium@495776      0.266762 +- 0.0128326       6      good
chromium@495792      0.266774 +- 0.0108291       6      good
chromium@495800      0.265128 +- 0.00795611      6      good
chromium@495801      0.260932 +- 0.0097442       6      good
chromium@495802      0.280552 +- 0.00667627      6      bad       <--
chromium@495804      0.279638 +- 0.0132017       6      bad
chromium@495808      0.282592 +- 0.00651118      6      bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=release_x64 --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests --story-filter=browse.social.tumblr.infinite.scroll system_health.common_desktop

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8970262922476451008


For feedback, file a bug with component Speed>Bisection

=== 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    : system_health.common_desktop
  Metric       : cpu_time_percentage_avg/browse_social/browse_social_twitter
  Change       : 6.60% | 0.168671833757 -> 0.179798391058

Revision             Result                     N
chromium@495787      0.168672 +- 0.0592659      14      good
chromium@495798      0.175273 +- 0.0515812      14      good
chromium@495801      0.170919 +- 0.047147       9       good
chromium@495802      0.190072 +- 0.0623172      9       bad       <--
chromium@495803      0.191095 +- 0.0651386      9       bad
chromium@495808      0.179798 +- 0.110172       14      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=browse.social.twitter system_health.common_desktop

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8970262915354283200


For feedback, file a bug with component Speed>Bisection