All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=663159

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgk6zptgoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgk4nwvQoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgk9PavQoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgk_W3vwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgk5r9pQoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgk5rntAoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgo4SFvgkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg44XHmwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg46P29wgM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgk66PsAoM


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

android-nexus5
android-nexus5X
android-nexus6
android-nexus7v2
android-nexus9

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8996606425390468128

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

Hi timvolodine@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 : Add AndroidSpellChecker experiment for fieldtrial testing.
Author  : timvolodine
Commit description:
  
This CL adds an "AndroidSpellChecker" experiment to the field trials
under test for the Android platform. It tests enabling spellchecking
in Chrome on Android by default on non low-end devices.

BUG=650851,629609

Review-Url: https://codereview.chromium.org/2475013002
Cr-Commit-Position: refs/heads/master@{#429982}
Commit  : 821e4ef0cc2d7f7c68a538ebc6fed627f8fb802b
Date    : Fri Nov 04 19:51:44 2016


===== TESTED REVISIONS =====
Revision         Mean      Std Dev      N  Good?
chromium@429974  0.356363  0.00277005   5  good
chromium@429979  0.359393  0.00365039   5  good
chromium@429981  0.356808  0.00401137   4  good
chromium@429982  0.302883  0.00131597   5  bad    <--
chromium@429983  0.303316  0.00141541   6  bad
chromium@429992  0.30722   0.000909425  4  bad
chromium@430009  0.303049  0.0021162    6  bad

Bisect job ran on: android_nexus5X_perf_bisect
Bug ID: 663159

Test Command: src/tools/perf/run_benchmark -v --browser=android-chromium --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests blink_perf.dom
Test Metric: textarea-edit/textarea-edit
Relative Change: 14.90%
Score: 99.9

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/android_nexus5X_perf_bisect/builds/841
Job details: https://chromeperf.appspot.com/buildbucket_job_status/8996606425390468128


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5868020180713472

| 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!

looking at the graphs the regressions seem to be situated around editable html elements, so it's definitely possible enabling spellcheck is causing this..

Tim, can you follow up by reverting and verifying locally? We still need a resolution for this regression. 

Looks like these graphs recovered in April.