All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=747049

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=d5b61c89ddbfe4685568c30f2366607c6c9184074cd08f649f4e833851ec3190


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

chromium-rel-mac11-air
chromium-rel-mac12-mini-8gb
chromium-rel-win7-dual
win-high-dpi

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8973529194226906608

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

Suspected Commit
  Author : Yang Guo
  Commit : a2ab1353f6708b44d305fdd9fe65a6d29b95c6d6
  Date   : Tue Jul 18 10:48:43 2017
  Subject: [snapshot] Rehash strings after deserialization.

Bisect Details
  Configuration: win_perf_bisect
  Benchmark    : media.tough_video_cases_tbmv2
  Metric       : memory:chrome:all_processes:reported_by_chrome:v8:effective_size_avg/video.html?src_crowd1080.mp4
  Change       : 11.90% | 4407296.0 -> 4931584.0

Revision                           Result              N
chromium@487395                    4407296 +- 0.0      6      good
chromium@487445                    4407296 +- 0.0      6      good
chromium@487470                    4407296 +- 0.0      6      good
chromium@487476                    4407296 +- 0.0      6      good
chromium@487479                    4407296 +- 0.0      6      good
chromium@487479,v8@a2ab1353f6      4931584 +- 0.0      6      bad       <--
chromium@487479,v8@afcc8bb200      4931584 +- 0.0      6      bad
chromium@487479,v8@10c6fb566f      4931584 +- 0.0      6      bad
chromium@487480                    4931584 +- 0.0      6      bad
chromium@487481                    4931584 +- 0.0      6      bad
chromium@487482                    4931584 +- 0.0      6      bad
chromium@487494                    4931584 +- 0.0      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 --story-filter=video.html.src.crowd1080.mp4 media.tough_video_cases_tbmv2

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8973529194226906608


For feedback, file a bug with component Speed>Bisection