All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=750821

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=50a9d36eaadf0d03f34044af9d83e8a54b611ebcd4846f8411cdd81100ffd9d9


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

android-nexus7v2
android-webview-nexus5X
chromium-rel-mac11
chromium-rel-mac11-pro
chromium-rel-win7-gpu-intel
chromium-rel-win7-x64-dual
chromium-rel-win8-dual

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8972524594748870544

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

Suspected Commit
  Author : Ulan Degenbaev
  Commit : 774a4c5e240569b551cc9d19ae8cac146891d4c4
  Date   : Fri Jul 28 19:42:31 2017
  Subject: Revert "[heap] Reland "[heap] Allow a minimum semi-space size of 512K.""

Bisect Details
  Configuration: win_x64_perf_bisect
  Benchmark    : memory.long_running_idle_gmail_tbmv2
  Metric       : v8-gc-scavenger_avg/v8-gc-scavenger_avg
  Change       : 36.55% | 0.961188155847 -> 1.31248212366

Revision                           Result                    N
chromium@490644                    0.961188 +- 0.130997      6      good
chromium@490651                    0.903282 +- 0.162016      6      good
chromium@490652                    0.933962 +- 0.151615      6      good
chromium@490652,v8@59ddd6061c      0.88597 +- 0.148029       6      good
chromium@490652,v8@e567dd3ab4      0.916881 +- 0.166804      6      good
chromium@490652,v8@774a4c5e24      1.33772 +- 0.046764       6      bad       <--
chromium@490652,v8@4a9718c777      1.24405 +- 0.23548        6      bad
chromium@490653                    1.24201 +- 0.17036        6      bad
chromium@490654                    1.26196 +- 0.142997       6      bad
chromium@490657                    1.26705 +- 0.192115       6      bad
chromium@490669                    1.31248 +- 0.0995999      6      bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=release_x64 --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/8972524594748870544


For feedback, file a bug with component Speed>Bisection