All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=766617

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=4eb133c7fd848e77f8759fc4adc83269aec5f7d02198eda8b444c3f090a4c0fc


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

chromium-rel-mac12

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8968029837152242560

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

Suspected Commit
  Author : Kenneth Russell
  Commit : cdc786f5d2a2b538f4914ba0afbaee15634206b9
  Date   : Sat Sep 16 21:07:21 2017
  Subject: Use 8x MSAA rather than 4x MSAA when available.

Bisect Details
  Configuration: mac_10_12_perf_bisect
  Benchmark    : smoothness.tough_webgl_cases
  Metric       : frame_times/http___webglsamples.org_dynamic-cubemap_dynamic-cubemap.html
  Change       : 2.07% | 16.6842692308 -> 17.029144154

Revision             Result                     N
chromium@502508      16.6843 +- 0.00225949      6      good
chromium@502511      16.6846 +- 0.0027843       6      good
chromium@502512      16.6838 +- 0.00186861      6      good
chromium@502513      17.0291 +- 0.445083        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=http...webglsamples.org.dynamic.cubemap.dynamic.cubemap.html smoothness.tough_webgl_cases

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8968029837152242560


For feedback, file a bug with component Speed>Bisection