All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=748534

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=cd404083a25ce4fd0fc43ae2a8bf7e3b1683eb970c58aafa02619c4d78e4ba1e


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

chromium-rel-win7-dual

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8973089209783935664

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

Suspected Commit
  Author : Ulan Degenbaev
  Commit : 176a2b24fb23a0c9a3bc9eec27f6445dbfa5ab27
  Date   : Wed Jul 19 13:04:47 2017
  Subject: [heap] Reland "[heap] Allow a minimum semi-space size of 512K."

Bisect Details
  Configuration: win_perf_bisect
  Benchmark    : v8.runtimestats.browsing_desktop
  Metric       : v8-gc-phantom-handle-callback_sum/browse_media/browse_media_tumblr
  Change       : 36.33% | 0.429357142857 -> 0.585357142857

Revision                           Result                    N
chromium@488658                    0.429357 +- 0.69921       14      good
chromium@488711                    0.352143 +- 0.365893      14      good
chromium@488738                    0.381556 +- 0.319835      9       good
chromium@488745                    0.380571 +- 0.322427      14      good
chromium@488745,v8@ae9a2d38f3      0.403857 +- 0.804852      21      good
chromium@488745,v8@91c1a81d0e      0.374429 +- 0.643338      14      good
chromium@488745,v8@bb29f9a4d6      0.416952 +- 0.888607      21      good
chromium@488745,v8@176a2b24fb      0.591643 +- 0.593145      14      bad       <--
chromium@488745,v8@7cfd0c249e      0.598643 +- 0.57148       14      bad
chromium@488745,v8@b23b8c088c      0.715222 +- 0.756139      9       bad
chromium@488746                    0.611786 +- 0.922365      14      bad
chromium@488747                    0.560556 +- 0.492729      9       bad
chromium@488748                    0.615556 +- 0.697893      9       bad
chromium@488751                    0.688857 +- 0.880428      14      bad
chromium@488763                    0.585357 +- 0.51804       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.media.tumblr v8.runtimestats.browsing_desktop

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8973089209783935664


For feedback, file a bug with component Speed>Bisection