All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=629885

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg6qznowsM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgqu_5-woM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgquf_sgoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg6oThpQoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg6tbkpAoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgqs6xqwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgqrXNsgoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg6vTovgkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgqueouAkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgqpKvuAsM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgqr_spwsM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgqufrowoM


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

chromium-rel-win8-dual

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/9006597924253299040

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


=== Bisection aborted ===
The bisect was aborted because The metric values for the initial "good" and "bad" revisions do not represent a clear regression.
Please contact the the team (see below) if you believe this is in error.

=== Warnings ===
The following warnings were raised by the bisect job:

 * Bisect failed to reproduce the regression with enough confidence.

===== TESTED REVISIONS =====
Revision         Mean      Std Dev   N   Good?
chromium@406250  0.140297  0.11297   18  good
chromium@406261  0.183316  0.302741  18  bad

Bisect job ran on: win_8_perf_bisect
Bug ID: 629885

Test Command: .\src\out\Release\performance_browser_tests.exe --test-launcher-print-test-stdio=always --enable-gpu
Test Metric: CastV2Performance_gpu_30fps_bad/audio_jitter
Relative Change: 215.99%
Score: 0

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/win_8_perf_bisect/builds/2046
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9006597924253299040


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5861723102248960

| 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!

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/9006485229084287968

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/9005790555361891360

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/9005790530426280912

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


=== Bisection aborted ===
The bisect was aborted because The metric values for the initial "good" and "bad" revisions do not represent a clear regression.
Please contact the the team (see below) if you believe this is in error.

=== Warnings ===
The following warnings were raised by the bisect job:

 * Bisect failed to reproduce the regression with enough confidence.

===== TESTED REVISIONS =====
Revision         Mean      Std Dev   N   Good?
chromium@406000  0.751322  1.58853   18  good
chromium@406500  0.426573  0.938181  18  bad

Bisect job ran on: win_8_perf_bisect
Bug ID: 629885

Test Command: .\src\out\Release\performance_browser_tests.exe --test-launcher-print-test-stdio=always --enable-gpu
Test Metric: CastV2Performance_gpu_30fps_bad/audio_jitter
Relative Change: 83.72%
Score: 0

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/win_8_perf_bisect/builds/2067
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9005790530426280912


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5799615551504384

| 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!

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


=== Bisection aborted ===
The bisect was aborted because The metric values for the initial "good" and "bad" revisions do not represent a clear regression.
Please contact the the team (see below) if you believe this is in error.

=== Warnings ===
The following warnings were raised by the bisect job:

 * Bisect failed to reproduce the regression with enough confidence.

===== TESTED REVISIONS =====
Revision         Mean      Std Dev    N   Good?
chromium@406000  0.168858  0.0768822  18  good
chromium@406400  0.165965  0.0672664  18  bad

Bisect job ran on: win_8_perf_bisect
Bug ID: 629885

Test Command: .\src\out\Release\performance_browser_tests.exe --test-launcher-print-test-stdio=always --enable-gpu
Test Metric: CastV2Performance_gpu_30fps_slow/send_to_renderer
Relative Change: 1.17%
Score: 0

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/win_8_perf_bisect/builds/2066
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9005790555361891360


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5262379835719680

| 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!

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/9005129241337991664

I sent off a bisect, but it strikes me that these are all the same bot. Did something happen to it? We don't appear to have ref builds here.

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


=== Bisection aborted ===
The bisect was aborted because The metric values for the initial "good" and "bad" revisions do not represent a clear regression.
Please contact the the team (see below) if you believe this is in error.

=== Warnings ===
The following warnings were raised by the bisect job:

 * Bisect failed to reproduce the regression with enough confidence.

===== TESTED REVISIONS =====
Revision         Mean     Std Dev    N   Good?
chromium@406250  33.3887  0.0944244  18  good
chromium@406261  33.3709  0.0619137  18  bad

Bisect job ran on: win_8_perf_bisect
Bug ID: 629885

Test Command: .\src\out\Release\performance_browser_tests.exe --test-launcher-print-test-stdio=always --enable-gpu
Test Metric: CastV2Performance_gpu_30fps_bad/time_between_captures
Relative Change: 0.10%
Score: 0

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/win_8_perf_bisect/builds/2098
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9005129241337991664


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5901253972852736

| 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!

Perf sheriff ping: reminder to follow up on possible performance issues

perf sheriff fixit: unsetting perf sheriffs as bug owners to clarify the rotation triages the bugs.

The bisects have not led to anything actionable. Based on manual examination of the CL range, I suspect this change:

commit	caa8d6675e165cd04fc22f24b36c1076d6720388	
author	fdoray <fdoray@chromium.org>	Tue Jul 19 13:18:54 2016
committer	Commit bot <commit-bot@chromium.org>	Tue Jul 19 13:20:49 2016
TaskScheduler: Atomic operations in TaskTracker

However, that change would only shuffle-around the timing of thread task execution. So, even though that change has harmed tab capture performance a little, it's not clear that any action should be taken because the change may be globally more optimal.

fdoray: Do you agree? If so, please close as WontFix.

The code in base/task_scheduler isn't used yet (except in base/task_scheduler tests). Therefore, it can't be responsible for a performance regression in performance _browser_tests.