All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=645302

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg8fz5gggM


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

android-nexus5

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/9002044128750069216

===== 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@416447  17.9083  0.0962164  18  good
chromium@416451  17.9238  0.0911173  18  bad

Bisect job ran on: android_nexus5_perf_bisect
Bug ID: 645302

Test Command: src/tools/perf/run_benchmark -v --browser=android-chromium --output-format=chartjson --upload-results --also-run-disabled-tests smoothness.gpu_rasterization.top_25_smooth
Test Metric: frame_times/frame_times
Relative Change: 0.07%
Score: 0

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/android_nexus5_perf_bisect/builds/4103
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9002044128750069216


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=6063093816229888

| 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/9000695610212095904

===== 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@416447  18.3563  0.824405  18  good
chromium@416451  18.6024  0.634142  18  bad

Bisect job ran on: android_nexus5_perf_bisect
Bug ID: 645302

Test Command: src/tools/perf/run_benchmark -v --browser=android-chromium --output-format=chartjson --upload-results --also-run-disabled-tests smoothness.gpu_rasterization.top_25_smooth
Test Metric: frame_times/ESPN
Relative Change: 2.35%
Score: 0

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/android_nexus5_perf_bisect/builds/4145
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9000695610212095904


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5771526731726848

| 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 fixit: removing perf sheriff as owner of bugs to clarify that the rotation is responsible for triage.

While there may have been a real regression in here, it was small. It's more or less recovered at this point, as the signal is relatively noisy. This bug is two months old, so I'm doubtful that we will get a working bisect at this point. Plus, bisect did actually work, but it wasn't significant enough to do anything about.