All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=752529

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=5cae37e6573c297dae40398384415103a3535b9055d14e9f715b424c6539c14e


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

android-nexus5X

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8972178041732366768

=== 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 : 2cc8fdfb47226101b958da465d64803368fb7c76
  Date   : Thu Jul 27 11:09:24 2017
  Subject: [heap] Re-implement weak cell tracking in the marker.

Bisect Details
  Configuration: android_nexus5X_perf_bisect
  Benchmark    : v8.runtimestats.browsing_mobile
  Metric       : v8-gc-latency-mark-compactor_avg/browse_social/browse_social_pinterest_infinite_scroll
  Change       : 35.18% | 7.04321388889 -> 9.52115277778

Revision                           Result                   N
chromium@490022                    7.04321 +- 1.10388       6      good
chromium@490026                    7.34951 +- 2.08932       6      good
chromium@490027                    6.71326 +- 0.647929      6      good
chromium@490027,v8@2cc8fdfb47      9.94248 +- 1.47801       6      bad       <--
chromium@490027,v8@6a75fcd4df      9.80488 +- 1.26752       6      bad
chromium@490027,v8@e4bbf92be3      9.82596 +- 2.38019       6      bad
chromium@490027,v8@9836cdb1ad      9.70531 +- 2.16997       6      bad
chromium@490028                    9.22717 +- 1.33834       6      bad
chromium@490029                    10.0855 +- 0.803384      6      bad
chromium@490036                    9.61779 +- 0.776485      6      bad
chromium@490050                    9.92143 +- 1.57734       6      bad
chromium@490077                    9.84599 +- 0.84372       6      bad
chromium@490131                    9.52115 +- 1.22157       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.pinterest.infinite.scroll 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/8972178041732366768


For feedback, file a bug with component Speed>Bisection

The CL improves memory usage and GC time in other benchmarks.