All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=611041

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgICg9IyQpwoM


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

android-nexus5

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

Hi mastiz@chromium.org, the bisect results pointed to your CL below as possibly
causing a regression. Please have a look at this info and see whether
your CL be related.


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


===== SUSPECTED CL(s) =====
Subject : [NTP Snippets] Add histogram with fetch time
Author  : mastiz
Commit description:
  
Client-side fetch latency can be useful to detect degradation in user
experience and release qualification (i.e. migration to new backend).

BUG= 584428 

Review-Url: https://codereview.chromium.org/1961943002
Cr-Commit-Position: refs/heads/master@{#392569}
Commit  : 5dce6eed8747d19117ab4d928caffbe9568bc830
Date    : Tue May 10 09:04:44 2016


===== TESTED REVISIONS =====
Revision         Mean     Std Dev  N  Good?
chromium@392563  69.7132  1.18315  5  good
chromium@392568  68.3364  1.76673  8  good
chromium@392569  62.6945  3.49502  8  bad    <--
chromium@392570  63.4436  3.55325  8  bad
chromium@392572  59.8772  1.16539  5  bad

Bisect job ran on: android_nexus5_perf_bisect
Bug ID: 611041

Test Command: src/tools/perf/run_benchmark -v --browser=android-chromium --output-format=chartjson --upload-results --also-run-disabled-tests blink_perf.bindings
Test Metric: set-attribute/set-attribute
Relative Change: 14.11%
Score: 99.0

Buildbot stdio: http://build.chromium.org/p/tryserver.chromium.perf/builders/android_nexus5_perf_bisect/builds/3684
Job details: https://chromeperf.appspot.com/buildbucket_job_status/9012953144569811120


Not what you expected? We'll investigate and get back to you!
  https://chromeperf.appspot.com/bad_bisect?try_job_id=5807132377612288

| 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!

I seems very unlikely that this patch is the culprit, with only one UMA histogram added in a non-performance-critical codepath, where other histograms already were present.

Charts suggest the performance degradation improved later, independently from this patch. I'll mark this as fixed unless I hear back after a grace period.