All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=798317

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=044646859c43e09b1ef2d5ab7c09c5137145f732c123f9f9fa9fa28008d86824


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

android-webview-nexus6
chromium-rel-mac12
chromium-rel-mac12-mini-8gb
chromium-rel-win7-dual
chromium-rel-win7-gpu-intel
chromium-rel-win7-gpu-nvidia
win-high-dpi

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8958520581835291424

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

Suspected Commit
  Author : Chris Harrelson
  Commit : d45f384824617447c7e4e8808b4946230dab58e2
  Date   : Sat Dec 30 01:02:37 2017
  Subject: Revert "Revert "[CI] Migrate hit-testing code in PaintLayer to use GeometryMapper.""

Bisect Details
  Configuration: android_webview_nexus6_aosp_perf_bisect
  Benchmark    : blink_perf.layout
  Metric       : multicol_tall-content-short-columns-realistic/multicol_tall-content-short-columns-realistic
  Change       : 99.58% | 1103.89681177 -> 4.66447263694

Revision             Result                    N
chromium@526398      1103.9 +- 23.9961         6      good
chromium@526399      1091.72 +- 21.3897        6      good
chromium@526400      4.61569 +- 0.0484738      6      bad       <--
chromium@526401      4.61703 +- 0.0802321      6      bad
chromium@526404      4.66447 +- 0.0713948      6      bad

Please refer to the following doc on diagnosing blink_perf regressions:
  https://chromium.googlesource.com/chromium/src/+/master/docs/speed/benchmark_harnesses/blink_perf.md

To Run This Test
  src/tools/perf/run_benchmark -v --browser=android-webview --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests blink_perf.layout

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8958520581835291424


For feedback, file a bug with component Speed>Bisection