All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=758313

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=784e8ec7e6389660c469e454c20230c76a0e77832370b2b0d1ab495a22fc3342


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

chromium-rel-win7-dual

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8970444919274364352

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

Bisect Details
  Configuration: win_perf_bisect
  Benchmark    : thread_times.tough_scrolling_cases
  Metric       : thread_total_all_cpu_time_per_frame/text_hover_40000_pixels_per_second

Revision             Result                  N
chromium@495791      37.947 +- 6.3658        21      good
chromium@495808      38.1224 +- 4.92805      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=text.hover.40000.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/8970444919274364352


For feedback, file a bug with component Speed>Bisection

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8970438543756823280

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8970438525095301712

=== 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_perf_bisect
  Benchmark    : thread_times.tough_scrolling_cases
  Metric       : thread_raster_cpu_time_per_frame/text_60000_pixels_per_second
  Change       : 19.66% | 8.36739878819 -> 10.0127145844

Revision             Result                  N
chromium@495791      8.3674 +- 1.0799        6       good
chromium@495800      8.18908 +- 1.63349      9       good
chromium@495801      8.22156 +- 1.81441      14      good
chromium@495802      9.04102 +- 2.04303      9       bad       <--
chromium@495804      9.2771 +- 1.7325        9       bad
chromium@495808      10.0127 +- 1.51023      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.60000.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/8970438525095301712


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_perf_bisect
  Benchmark    : thread_times.tough_scrolling_cases
  Metric       : thread_raster_cpu_time_per_frame/canvas_05000_pixels_per_second
  Change       : 11.83% | 0.594687724843 -> 0.675820078263

Revision             Result                     N
chromium@495791      0.594688 +- 0.222845       14      good
chromium@495800      0.611947 +- 0.232448       14      good
chromium@495801      0.564885 +- 0.0404326      6       good
chromium@495802      0.682764 +- 0.192025       21      bad       <--
chromium@495804      0.68352 +- 0.137949        14      bad
chromium@495808      0.67582 +- 0.10302         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=canvas.05000.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/8970438543756823280


For feedback, file a bug with component Speed>Bisection