All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=763922

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=18d9463e5f4e2e28b2e2197b11c04f432e28fb30578b3aca5425dd1d3e64912a


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

android-webview-nexus5X
chromium-rel-mac-retina

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8968742822652487872

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

Suspected Commit
  Author : Vladimir Levin
  Commit : c9aa97407de3305265e662d3dee32c2a006923b2
  Date   : Thu Sep 07 21:24:57 2017
  Subject: images: Plumb decoding to scale for JPEGs in software.

Bisect Details
  Configuration: mac_retina_perf_bisect
  Benchmark    : v8.browsing_desktop
  Metric       : v8-gc-incremental-step_avg/browse_social/browse_social_twitter
  Change       : 24.92% | 0.352766858736 -> 0.457154277905

Revision             Result                     N
chromium@500317      0.352767 +- 0.101745       14      good
chromium@500356      0.380706 +- 0.202687       14      good
chromium@500375      0.364163 +- 0.14303        9       good
chromium@500380      0.375158 +- 0.0830188      6       good
chromium@500383      0.366379 +- 0.116768       9       good
chromium@500384      0.454298 +- 0.207559       14      bad       <--
chromium@500385      0.458807 +- 0.198451       14      bad
chromium@500394      0.457154 +- 0.181063       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 v8.browsing_desktop

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8968742822652487872


For feedback, file a bug with component Speed>Bisection