All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=731681

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg5oOFrAoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg5oHimQsM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg5ouWiggM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg5o3R8AgM


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

android-nexus5
android-nexus7v2

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8977267041054585200

=== BISECT JOB RESULTS ===
Perf regression found with culprit

Suspected Commit
  Author : cathiechen
  Commit : 47f9b0ff7d4594f6633956ac570966439b4d5125
  Date   : Tue Jun 06 04:51:41 2017
  Subject: Fix font-size shaking issue in some page

Bisect Details
  Configuration: android_nexus7_perf_bisect
  Benchmark    : blink_perf.layout
  Metric       : multicol_lots-of-text-balanced/multicol_lots-of-text-balanced
  Change       : 46.86% | 11.9958644594 -> 6.37412888198

Revision             Result                    N
chromium@477118      11.9959 +- 0.148761       6      good
chromium@477162      11.6032 +- 0.0733625      5      good
chromium@477184      11.9397 +- 0.15504        6      good
chromium@477195      11.8069 +- 0.126111       6      good
chromium@477197      11.9145 +- 0.259144       6      good
chromium@477198      6.41668 +- 0.0938249      6      bad       <--
chromium@477200      6.44604 +- 0.112948       6      bad
chromium@477205      6.37413 +- 0.0510379      6      bad

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.layout

Debug Info
  https://chromeperf.appspot.com/buildbucket_job_status/8977267041054585200

Is this bisect wrong?
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5272305673961472


| 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/+/aa7b8c388ea0b2af4eb1e14ba246c3e1b5893aee

commit aa7b8c388ea0b2af4eb1e14ba246c3e1b5893aee
Author: cathiechen <cathiechen@tencent.com>
Date: Wed Jun 28 09:33:38 2017

Element with columnCount > 1 should be classified as INDEPENDENT

The LayoutWidth of LayoutMultiColumnFlowThread is one columnCountth of
its parent node. The width difference between them is large. So element
with columnCount > 1 should create cluster anyway.

BUG= 731681 

Review-Url: https://codereview.chromium.org/2961583003
Cr-Commit-Position: refs/heads/master@{#482927}

[modify] https://crrev.com/aa7b8c388ea0b2af4eb1e14ba246c3e1b5893aee/third_party/WebKit/Source/core/layout/TextAutosizer.cpp
[modify] https://crrev.com/aa7b8c388ea0b2af4eb1e14ba246c3e1b5893aee/third_party/WebKit/Source/core/layout/TextAutosizerTest.cpp