All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=723179

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg6q7y5QkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg6qrngAsM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDgqp7d9goM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg6rmyvAoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg6sTC_QkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg6ojt_woM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg6u2dvwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDgmuTJtgoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg6uT85QgM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg6vnwpwkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg6tncoQoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg6qnFvgkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg6uXgrQoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg6r33pAoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDgqtr5qwsM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDgqs_kywkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDgqrPG3ggM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg6vXksAoM


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

chromium-rel-mac11
chromium-rel-mac11-air
chromium-rel-mac11-pro
chromium-rel-mac12
chromium-rel-mac12-mini-8gb
chromium-rel-win10
chromium-rel-win7-dual
chromium-rel-win7-gpu-ati
chromium-rel-win7-x64-dual
chromium-rel-win8-dual

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8979389438578101424

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

Hi yhirano@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 : yhirano
  Commit : 97c0d877b1aff4ac84138c3eab71d994ead93b14
  Date   : Thu May 11 05:39:25 2017
  Subject: Revert "Separate preaload matching from MemoryCache"

Bisect Details
  Configuration: win_perf_bisect
  Benchmark    : page_cycler_v2_site_isolation.basic_oopif
  Metric       : timeToFirstMeaningfulPaint_avg/pcv1-warm/http___www.cnn.com
  Change       : 23.41% | 655.780666666 -> 837.391785714

Revision             Result                  N
chromium@470765      655.781 +- 12.0454      6       good
chromium@470798      661.304 +- 40.4168      9       good
chromium@470815      711.217 +- 385.951      14      good
chromium@470823      727.085 +- 504.516      21      good
chromium@470824      694.716 +- 231.473      14      good
chromium@470825      845.377 +- 430.126      14      bad       <--
chromium@470827      825.71 +- 156.17        14      bad
chromium@470831      837.392 +- 228.75       14      bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=release --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests --story-filter=http...www.cnn.com page_cycler_v2_site_isolation.basic_oopif

Debug Info
  https://chromeperf.appspot.com/buildbucket_job_status/8979389438578101424

Is this bisect wrong?
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5808955671969792


| 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 interesting.

This is a revert CL, and the reason of revert is perf regression. But it seems the original CL brought some perf improvements as well.

I'll keep this open for a while.

See also:  issue 719502