All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=652841

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg1e-KoQsM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg1e-K4QgM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg1eqfogoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg1YnztQkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg1buzrwoM


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

chromium-rel-win7-dual

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8999698384061369632

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

Hi xiaochengh@chromium.org, the bisect results pointed to your CL below as possibly
causing a regression. Please have a look at this info and see whether
your CL be related.


===== BISECT JOB RESULTS =====
Status: completed


===== SUSPECTED CL(s) =====
Subject : Prune CreateVisiblePositionDeprecated from VisibleSelection::visibleBase/Extent
Author  : xiaochengh
Commit description:
  
Caller of these two functions have already ensured clean layout, so this
patch safely prunes CreateVisiblePositionDeprecated from them.

BUG= 647219 

Review-Url: https://codereview.chromium.org/2362183002
Cr-Commit-Position: refs/heads/master@{#420866}
Commit  : 0db24bb3a3073a9296b05d5bfc592727db2f94c4
Date    : Mon Sep 26 02:12:59 2016


===== TESTED REVISIONS =====
Revision         Mean    Std Dev   N  Good?
chromium@420865  12.292  0.619542  5  good
chromium@420866  15.806  1.41452   5  bad    <--
chromium@420867  16.358  1.6107    5  bad
chromium@420868  15.734  0.473437  5  bad
chromium@420871  14.989  1.32815   5  bad

Bisect job ran on: win_perf_bisect
Bug ID: 652841

Test Command: src/tools/perf/run_benchmark -v --browser=release --output-format=chartjson --upload-results --also-run-disabled-tests media.tough_video_cases_extra
Test Metric: seek/tulip2.ogv_seek_cold
Relative Change: 21.94%
Score: 99.5

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/win_perf_bisect/builds/6969
Job details: https://chromeperf.appspot.com/buildbucket_job_status/8999698384061369632


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5237317390827520

| O O | Visit http://www.chromium.org/developers/speed-infra/perf-bug-faq
|  X  | for more information addressing perf regression bugs. For feedback,
| / \ | file a bug with component Tests>AutoBisect.  Thank you!

Passing back to the reporter as I think this is a false alert.

According to the performance dashboard, this test case was fluctuating since r419390, and the suspected CL is just at the end of the fluctuation.

The suspected CL doesn't change anything essential. Replacing createVisiblePositionDeprecated by createVisiblePosition can't regress the performance, as cVPD is simply a layout update followed by cVP.