All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=640902

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICgvvnqqQoM


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

android-nexus7v2

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/9003369509885438416

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/9000475302459233936

===== BISECT JOB RESULTS =====
Status: failed


===== TESTED REVISIONS =====
Revision         Mean     Std Dev  N   Good?
chromium@414145  2313.79  54.0728  18  good
chromium@414163  2330.91  14.2613  5   good
chromium@414172  2342.03  34.7561  5   good
chromium@414181  2404.39  16.4473  5   bad
chromium@414216  2372.97  47.6075  18  bad
chromium@414287  2406.66  37.4491  18  bad

Bisect job ran on: android_nexus7_perf_bisect
Bug ID: 640902

Test Command: src/tools/perf/run_benchmark -v --browser=android-chromium --output-format=chartjson --upload-results --also-run-disabled-tests speedometer
Test Metric: VanillaJS-TodoMVC/VanillaJS-TodoMVC
Relative Change: 1.70%
Score: 0

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/android_nexus7_perf_bisect/builds/3329
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9000475302459233936


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5847529600581632

| 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!

For some reason this was not automatically assigned after the bisection.
It seems that the guilty revision is chromium@414181.
https://chromium.googlesource.com/chromium/src/+/3e988531f70d2489982275e0fc26e18f8cc6c9ca

That CL does not run on Android, so I don't think that this is the right culprit. Furthermore that graph has gone down again for some other reasons perhaps. So I'm marking WONTFIX.