All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=759033

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=568cb790cb173596573791e31ac3cfff38b4a2cffd382cbf1c3e5e8cf2a31955


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

chromium-rel-mac11

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8970275208602862000

=== BISECT JOB RESULTS ===
Bisect was unable to run to completion

Please try rerunning the bisect.


If failures persist contact the team (see below) and report the error.


Bisect Details
  Configuration: mac_10_11_perf_bisect
  Benchmark    : loading.desktop
  Metric       : timeToFirstMeaningfulPaint_avg/pcv1-cold/HTML5Rocks

Revision             Result                  N
chromium@494277      55.9301 +- 9.82989      14      good
chromium@494830      142.433 +- 9.58823      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=HTML5Rocks loading.desktop

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8970275208602862000


For feedback, file a bug with component Speed>Bisection

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/14fd1f60780000

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/14ee08a0780000

More failing bisects. trying again in pinpoint.

📍 Pinpoint job stopped with an error.
https://pinpoint-dot-chromeperf.appspot.com/job/14fd1f60780000

Reland "[tools/perf] Re-enable start_wit_ext.* benchmarks"
By perezju@chromium.org · Tue Aug 15 11:03:29 2017
chromium@62a75552b011f0c227a7f0a7e573dfe696c99a46

📍 Pinpoint job completed.
https://pinpoint-dot-chromeperf.appspot.com/job/14ee08a0780000

Enable Finch Trial Test for MacV2Sandbox.
By kerrnel@chromium.org · Tue Aug 15 19:42:42 2017
chromium@9705b7aaabf4c81d4e9cb13174338df9bde61cc4

Comment 8 looks right.
Comment 7 looks like https://github.com/catapult-project/catapult/issues/3878.
Please ignore the results, they are bogus. I'm going to re-kick that job.

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/12b6783fb80000

📍 Pinpoint job completed.
https://pinpoint-dot-chromeperf.appspot.com/job/12b6783fb80000

Found significant differences after each of 2 commits:

Convert loading.desktop page set to WprGo
By ksakamoto@chromium.org · Tue Aug 15 04:08:53 2017
chromium@ca2e6be7bac44462efdd864ef346311b9a6033de

Change error pages to use a new chrome-error:// scheme.
By alexmos@chromium.org · Wed Aug 16 16:20:00 2017
chromium@71f48559772345f1005a0e24eb27b01feada9439

This looks like  issue 755983 .

Whoops, I meant #11 looks like  issue 755983 . There's also comment #8.

Agreed with dtu@ that there are two regressions and the re-recording in #11 means that all the graphs do not look fully recovered after MacV2Sandbox was reverted. But let's keep this bug about the sandbox, since I already removed unrelated alerts to a new bug. WontFix-ing because the change has been reverted, but assigning to kerrnel as FYI.

Thanks for helping to clarify this. I need to re-land the V2 sandbox at some point so this helps me understand what benchmarks to test before, and then monitor after re-submission.