All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=753999

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=d5d66ce7016f8a49848fe93aadc1271ce2001333fc445e842e28a4e74c260d82


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

chromium-rel-mac12-mini-8gb
chromium-rel-win7-gpu-intel

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8971702923863360032

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

Hi yosin@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 : Yoshifumi Inoue
  Commit : 44e59041eab4efb2d9cae5e3e7e5623963dd131a
  Date   : Thu Aug 03 07:13:06 2017
  Subject: Introduce SelectionForUndoStep

Bisect Details
  Configuration: winx64intel_perf_bisect
  Benchmark    : blink_perf.dom
  Metric       : textarea-edit/textarea-edit
  Change       : 10.47% | 3.33501184168 -> 2.98586548519

Revision             Result                    N
chromium@491547      3.33501 +- 0.0295111      6      good
chromium@491614      3.35514 +- 0.0191836      6      good
chromium@491647      3.30072 +- 0.0340688      6      good
chromium@491664      3.34527 +- 0.0321832      6      good
chromium@491666      3.34429 +- 0.0281658      6      good
chromium@491667      2.988 +- 0.0244545        6      bad       <--
chromium@491668      2.98914 +- 0.0246085      6      bad
chromium@491672      2.98999 +- 0.0080112      6      bad
chromium@491680      2.98587 +- 0.039307       6      bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=release_x64 --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests blink_perf.dom

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8971702923863360032


For feedback, file a bug with component Speed>Bisection

Mark WontFix since the patch in #c3 makes Chrome records collect selection for
undo/redo steps. It requires more update layout call than before.