All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=740531

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=9114939eb1cc64a52f67e255dd096d0541b6c3959954cbfe5e2df0c9f9ce8a20


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

chromium-rel-mac11-pro

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8974450521275383760

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

Suspected Commit
  Author : Yutaka Hirano
  Commit : 84047549ac37bab70d7306566c912e59131f3e1f
  Date   : Mon Jun 19 04:16:15 2017
  Subject: [Loading] Save one post-task when the data pipe is ready on arrival

Bisect Details
  Configuration: mac_pro_perf_bisect
  Benchmark    : system_health.common_desktop
  Metric       : timeToFirstMeaningfulPaint_avg/browse_media/browse_media_pinterest
  Change       : 64.11% | 1008.67108334 -> 361.994333327

Revision             Result                  N
chromium@480339      1008.67 +- 586.726      6      good
chromium@480341      1166.84 +- 285.349      6      good
chromium@480342      383.489 +- 108.347      6      bad       <--
chromium@480345      423.855 +- 201.873      9      bad
chromium@480350      374.203 +- 165.338      6      bad
chromium@480360      354.136 +- 79.1635      6      bad
chromium@480380      361.994 +- 84.969       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=browse.media.pinterest system_health.common_desktop

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8974450521275383760


For feedback, file a bug with component Speed>Bisection