All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=701361

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDgtOiTuAsM


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

chromium-rel-win7-gpu-intel

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8985136940938967088

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

Hi meade@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 : meade
  Commit : 3a001533b29c0fe28f2354285b2c2ac8d57d8ce6
  Date   : Mon Mar 13 05:26:20 2017
  Subject: Un-DCHECK-guard ThreadRestrictionVerifier for strings.

Bisect Details
  Configuration: winx64intel_perf_bisect
  Benchmark    : dromaeo.domcoreattr
  Metric       : dom/dom
  Change       : 12.93% | 871.463751029 -> 758.810801956

Revision             Result                  N
chromium@456305      871.464 +- 56.6529      6      good
chromium@456316      861.509 +- 48.1448      6      good
chromium@456321      860.316 +- 45.9053      6      good
chromium@456322      867.412 +- 34.6242      6      good
chromium@456323      747.877 +- 14.4579      6      bad       <--
chromium@456324      752.786 +- 9.9558       6      bad
chromium@456326      758.811 +- 10.3245      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 dromaeo.domcoreattr

Debug Info
  https://chromeperf.appspot.com/buildbucket_job_status/8985136940938967088

Is this bisect wrong?
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5789602872295424


| 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 Speed>Bisection.  Thank you!

This is expected while this CL is in to investigate Issue 694520. I'm planning on reverting it before Friday.

PSA to blink-dev: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/SupcNcaTh_g

Thanks for the info. Setting appropriate labels.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/32c86f9955aa028ea55a4538c61c67e0dbf6294e

commit 32c86f9955aa028ea55a4538c61c67e0dbf6294e
Author: meade <meade@chromium.org>
Date: Fri Mar 17 03:29:19 2017

Revert of Un-DCHECK-guard ThreadRestrictionVerifier for strings. (patchset #2 id:20001 of https://codereview.chromium.org/2743663003/ )

Reason for revert:
Reverting as I finish up my investigation.

BUG= 701361 

Original issue's description:
> Un-DCHECK-guard ThreadRestrictionVerifier for strings.
>
> This should help us debug various String crashes we've been seeing
> through the crash server, particularly the linked bug.
>
> Note that this will definitely make strings slow on Canary, and will
> possibly cause crashes other than the particular one I was looking
> for. These crashes will all be security bugs though, so we should
> get some valuable information regardless.
>
> PSA to blink-dev that I am doing this investigation is here: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/SupcNcaTh_g
>
> This CL should be reverted by 17 March 2017.
> This CL should be reverted by 17 March 2017.
> This CL should be reverted by 17 March 2017.
> This CL should be reverted by 17 March 2017.
>
> BUG=694520
>
> Review-Url: https://codereview.chromium.org/2743663003
> Cr-Commit-Position: refs/heads/master@{#456323}
> Committed: https://chromium.googlesource.com/chromium/src/+/3a001533b29c0fe28f2354285b2c2ac8d57d8ce6

TBR=esprehn@chromium.org,csharrison@chromium.org,sigbjornf@opera.com,wez@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=694520

Review-Url: https://codereview.chromium.org/2753953002
Cr-Commit-Position: refs/heads/master@{#457672}

[modify] https://crrev.com/32c86f9955aa028ea55a4538c61c67e0dbf6294e/third_party/WebKit/Source/wtf/ThreadRestrictionVerifier.h
[modify] https://crrev.com/32c86f9955aa028ea55a4538c61c67e0dbf6294e/third_party/WebKit/Source/wtf/text/StringImpl.cpp
[modify] https://crrev.com/32c86f9955aa028ea55a4538c61c67e0dbf6294e/third_party/WebKit/Source/wtf/text/StringImpl.h