All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=758986

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=db65c75248d29ff91e251fe19a2f5e8b5b0762b6db69d5e7ce605c9d9abfa0a7


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

android-nexus6
android-nexus7v2
android-one
chromium-rel-mac-retina
chromium-rel-mac11
chromium-rel-mac11-air
chromium-rel-mac12
chromium-rel-mac12-mini-8gb
chromium-rel-win10
chromium-rel-win7-dual
chromium-rel-win7-gpu-intel
chromium-rel-win7-gpu-nvidia
chromium-rel-win7-x64-dual
chromium-rel-win8-dual
linux-release
win-high-dpi

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8970283784430108656

=== Auto-CCing suspected CL author ulan@chromium.org ===

Hi ulan@chromium.org, the bisect results pointed to your CL, please take a look at the
results.


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

Suspected Commit
  Author : Ulan Degenbaev
  Commit : d58937b88f53cd58b640ab3236596c7ac1efc5ba
  Date   : Tue Aug 22 18:14:38 2017
  Subject: [heap] Fix runtimestats scope for top-level GC tasks.

Bisect Details
  Configuration: android_nexus6_perf_bisect
  Benchmark    : v8.runtimestats.browsing_mobile
  Metric       : GC:duration_avg/browse_social/browse_social_twitter
  Change       : 3062.76% | 9.688 -> 306.408166667

Revision                           Result                  N
chromium@496535                    9.688 +- 14.839         6      good
chromium@496549                    7.0858 +- 8.43193       5      good
chromium@496556                    7.31767 +- 9.55345      6      good
chromium@496558                    5.22333 +- 10.2706      6      good
chromium@496558,v8@000ef276b1      5.68683 +- 9.78134      6      good
chromium@496558,v8@3710fd4a3d      5.07483 +- 7.78113      6      good
chromium@496558,v8@d58937b88f      293.46 +- 80.4257       6      bad       <--
chromium@496558,v8@c652a9eb2d      313.01 +- 69.8881       6      bad
chromium@496559                    306.731 +- 99.6343      6      bad
chromium@496562                    303.368 +- 55.459       6      bad
chromium@496588                    306.408 +- 22.4511      6      bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=android-chromium --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests --story-filter=browse.social.twitter v8.runtimestats.browsing_mobile

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8970283784430108656


For feedback, file a bug with component Speed>Bisection

My CL fixed accounting of the GC time.

 Issue 758852  has been merged into this issue.