All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=716385

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg0vaErQoM


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

chromium-rel-win7-gpu-nvidia

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8981079264379516384

=== Auto-CCing suspected CL author robhogan@gmail.com ===

Hi robhogan@gmail.com, 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 : robhogan
  Commit : 789b5e528fb3bd9ca44341de46547c45355652ab
  Date   : Wed Apr 26 22:12:06 2017
  Subject: Let siblings layout if an adjacent float may no longer affect them

Bisect Details
  Configuration: winx64nvidia_perf_bisect
  Benchmark    : page_cycler_v2.tough_layout_cases
  Metric       : timeToFirstMeaningfulPaint_avg/pcv1-warm/http___www.mossiella.com
  Change       : 62.48% | 561.005333332 -> 911.539833335

Revision             Result                  N
chromium@467361      561.005 +- 35.496       6      good
chromium@467427      562.632 +- 18.0693      6      good
chromium@467460      559.685 +- 17.6028      6      good
chromium@467477      579.402 +- 142.465      6      good
chromium@467478      551.263 +- 4.08568      6      good
chromium@467479      798.262 +- 74.0698      6      bad       <--
chromium@467481      867.984 +- 110.118      6      bad
chromium@467485      858.138 +- 314.128      6      bad
chromium@467493      911.54 +- 546.828       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 --story-filter=http...www.mossiella.com page_cycler_v2.tough_layout_cases

Debug Info
  https://chromeperf.appspot.com/buildbucket_job_status/8981079264379516384

Is this bisect wrong?
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5261478925434880


| 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!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4a961b8eca27af4108358a30753197754316524b

commit 4a961b8eca27af4108358a30753197754316524b
Author: robhogan <robhogan@gmail.com>
Date: Mon May 01 22:06:51 2017

Fix regression in page_cycler_v2.tough_layout_cases

Caused by https://codereview.chromium.org/2836293003. Instead detect
when margin has moved a float completely out of its former position
and mark any affected siblings for layout.

BUG= 716385 

Review-Url: https://codereview.chromium.org/2846923003
Cr-Commit-Position: refs/heads/master@{#468441}

[modify] https://crrev.com/4a961b8eca27af4108358a30753197754316524b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp