All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=783678

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=880bcd4e3590656f99674b7048eb14428f2891b560173bff39afd8238310f254


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

android-nexus5
chromium-rel-win10
chromium-rel-win7-dual
chromium-rel-win7-gpu-ati

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8963319799690870880

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

Suspected Commit
  Author : Ulan Degenbaev
  Commit : 6bb1d47e6e82f75ead36cdab209afc5dafa8329c
  Date   : Tue Nov 07 13:11:10 2017
  Subject: [heap] Re-enable concurrent marking.

Bisect Details
  Configuration: win_perf_bisect
  Benchmark    : memory.long_running_idle_gmail_tbmv2
  Metric       : memory:chrome:renderer_processes:reported_by_chrome:v8:effective_size_max/memory:chrome:renderer_processes:reported_by_chrome:v8:effective_size_max
  Change       : 6.11% | 83357696.0 -> 78267733.3333

Revision                           Result                   N
chromium@514622                    83357696 +- 1277624      6      good
chromium@514635                    83107840 +- 741455       6      good
chromium@514641                    82746027 +- 1658447      6      good
chromium@514641,v8@67d543ec31      83369984 +- 980853       6      good
chromium@514641,v8@6bb1d47e6e      77997397 +- 1152639      6      bad       <--
chromium@514641,v8@ac0661b358      78172160 +- 1615964      6      bad
chromium@514641,v8@80cb266c75      77997397 +- 882508       6      bad
chromium@514642                    77918208 +- 741455       6      bad
chromium@514643                    78092971 +- 1601726      6      bad
chromium@514644                    78092971 +- 1765016      6      bad
chromium@514647                    78442496 +- 741455       6      bad
chromium@514671                    77830827 +- 882508       6      bad
chromium@514719                    78267733 +- 605396       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 memory.long_running_idle_gmail_tbmv2

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8963319799690870880


For feedback, file a bug with component Speed>Bisection