All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=774540

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=eec6d4cff863f343a8d5c0dda75d86a7169ba8360fd6fcb777666878ac28415b


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

chromium-rel-mac11

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8965831473594339616

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

Hi lgrey@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 : Leonard Grey
  Commit : 6cd75a31d4e4b87287caefb10c508db04e2b488b
  Date   : Mon Oct 02 20:37:51 2017
  Subject: [Mac] Don't change latency/throughput QoS when backgrounding

Bisect Details
  Configuration: mac_10_11_perf_bisect
  Benchmark    : system_health.common_desktop
  Metric       : cpu_time_percentage_avg/multitab_misc/multitab_misc_typical24
  Change       : 7.66% | 0.614530976869 -> 0.6616031457

Revision             Result                     N
chromium@505478      0.614531 +- 0.0172634      6      good
chromium@505678      0.619919 +- 0.0195389      6      good
chromium@505728      0.552051 +- 0.586275       9      good
chromium@505753      0.622664 +- 0.0435482      9      good
chromium@505760      0.623887 +- 0.0216312      6      good
chromium@505763      0.619401 +- 0.0313118      6      good
chromium@505765      0.628359 +- 0.0257345      6      good
chromium@505766      0.671453 +- 0.0305215      6      bad       <--
chromium@505778      0.663152 +- 0.0409078      6      bad
chromium@505877      0.674174 +- 0.0373687      6      bad
chromium@506276      0.661603 +- 0.0194754      6      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=multitab.misc.typical24 system_health.common_desktop

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8965831473594339616


For feedback, file a bug with component Speed>Bisection

Is the CPU time regression for this CL acceptable/expected, or is this something that we should be concerned about?

Sort of. This is part of an experiment (render process backgrounding). The linked change makes the backgrounding less aggressive to match Windows behavior.

Without digging in too much, the metric name "cpu_time_percentage_avg/multitab_misc/multitab_misc_typical24" seems like it might be a use case where this was having a lot of impact. I don't think it's anything to worry about since I can't see it making things worse than default.

Got it. In that case, I'm going to close this bug as WontFix (expected)