All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=596474

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg4NGoqwoM


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

chromium-rel-mac10

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

Hi rockot@chromium.org, the bisect results pointed to your CL below as possibly
causing a regression. Please have a look at this info and see whether
your CL be related.


===== BISECT JOB RESULTS =====
Status: completed


===== SUSPECTED CL(s) =====
Subject : [mojo-edk] Stop using the sync broker on OS X
Author  : rockot
Commit description:
  
The sync broker is only needed for sandboxed shared
buffer allocation on POSIX, but it's not needed for
Mach shared buffers.

This stops using the broker on OS X.

BUG= 591742 , 590979 

Review URL: https://codereview.chromium.org/1809363002

Cr-Commit-Position: refs/heads/master@{#381908}
Commit  : 018a4e46c477ada7307ed5c7dad7eb58b7da75b5
Date    : Fri Mar 18 07:36:07 2016


===== TESTED REVISIONS =====
Revision                Mean Value  Std. Dev.   Num Values  Good?
chromium@381899         270.778947  1.230611    5           good
chromium@381904         272.252632  1.085283    5           good
chromium@381906         271.118421  0.938924    4           good
chromium@381907         272.242105  0.91585     5           good
chromium@381908         281.210526  0.929659    5           bad

Bisect job ran on: mac_10_10_perf_bisect
Bug ID: 596474

Test Command: src/tools/perf/run_benchmark -v --browser=release --output-format=chartjson --also-run-disabled-tests startup.warm.blank_page
Test Metric: open_tabs_time/open_tabs_time
Relative Change: 3.85%
Score: 99.9

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/mac_10_10_perf_bisect/builds/2053
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9017570470196258256


| 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 label Cr-Tests-AutoBisect.  Thank you!

I don't think so. The CL in question only deleted code which blocked process startup.

re-kicked bisect with modified range.

===== BISECT JOB RESULTS =====
Status: completed


===== SUSPECTED CL(s) =====
Subject : [mojo-edk] Stop using the sync broker on OS X
Author  : rockot
Commit description:
  
The sync broker is only needed for sandboxed shared
buffer allocation on POSIX, but it's not needed for
Mach shared buffers.

This stops using the broker on OS X.

BUG= 591742 , 590979 

Review URL: https://codereview.chromium.org/1809363002

Cr-Commit-Position: refs/heads/master@{#381908}
Commit  : 018a4e46c477ada7307ed5c7dad7eb58b7da75b5
Date    : Fri Mar 18 07:36:07 2016


===== TESTED REVISIONS =====
Revision                Mean Value  Std. Dev.   Num Values  Good?
chromium@381850         269.6       1.793957    5           good
chromium@381882         270.463158  1.241815    5           good
chromium@381899         273.663158  1.730691    5           good
chromium@381907         270.157895  2.20488     5           good
chromium@381908         282.926316  1.423293    5           bad         <-
chromium@381909         282.389474  1.905525    5           bad
chromium@381911         281.6       1.520679    5           bad
chromium@381915         282.305263  0.447214    5           bad

Bisect job ran on: mac_10_10_perf_bisect
Bug ID: 596474

Test Command: src/tools/perf/run_benchmark -v --browser=release --output-format=chartjson --also-run-disabled-tests startup.warm.blank_page
Test Metric: open_tabs_time/open_tabs_time
Relative Change: 4.71%
Score: 99.9

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/mac_10_10_perf_bisect/builds/2067
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9016953749273252544


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=596474

| 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 Tests>AutoBisect.  Thank you!

based on bisect result, rockot@ could you please check the issue.

not seeing any owner associated to 'startup.warm.blank_page' (Desktop/Mac) in Owners spreadsheet, adding sullivan@ could you please check and assign to the owner.

thanks in advance.

rockot, can you take a look?

My CL recovered several larger regressions by deleting some unnecessary code. If doing this happened to cause a small regression elsewhere - and it does appear to be the case when looking at the graphs - I don't know that there's much to be done here. Please re-open if you disagree.