All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=773322

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=325cde0d0aca1435c601cc0d012c57e6a4357007c799f6873a8de3f218a9c315


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

android-nexus5X

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8966104515175580752

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

Hi verwaest@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 : Toon Verwaest
  Commit : 04afb10f356efbe1c3e1662bfd67f55e78d2851e
  Date   : Fri Sep 29 10:21:41 2017
  Subject: Migrate StringLengthStub to TF builtin

Bisect Details
  Configuration: android_nexus5X_perf_bisect
  Benchmark    : blink_perf.bindings
  Metric       : first-child/first-child
  Change       : 14.46% | 170.224054323 -> 145.608358592

Revision                           Result                  N
chromium@505355                    170.224 +- 3.90132      6      good
chromium@505389                    167.581 +- 5.19822      6      good
chromium@505389,v8@0a346fc264      164.798 +- 3.32704      6      good
chromium@505389,v8@04afb10f35      147.756 +- 1.26246      6      bad       <--
chromium@505389,v8@cbaa568275      149.077 +- 3.4011       6      bad
chromium@505389,v8@69aa6e5736      149.336 +- 9.61993      6      bad
chromium@505390                    148.342 +- 5.26106      6      bad
chromium@505391                    149.551 +- 11.4998      6      bad
chromium@505392                    153.457 +- 11.4951      6      bad
chromium@505394                    149.099 +- 8.36819      6      bad
chromium@505398                    149.856 +- 3.84265      6      bad
chromium@505406                    148.882 +- 4.64114      6      bad
chromium@505423                    145.608 +- 1.70988      6      bad

Please refer to the following doc on diagnosing blink_perf regressions:
  https://chromium.googlesource.com/chromium/src/+/master/docs/speed/benchmark_harnesses/blink_perf.md

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

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8966104515175580752


For feedback, file a bug with component Speed>Bisection

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/12a93ffcf80000

📍 Couldn't reproduce a difference.
https://pinpoint-dot-chromeperf.appspot.com/job/12a93ffcf80000

My CL just moves around code. I'm pretty sure my CL doesn't regress performance. There might be a code alignment issue though. Assigning back to decide what to do next.

WontFix-ing since this graph is pretty noisy, and it looks like a return to previous levels.