All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=741737

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=2affd56ecf0df2294198043aacb0776a811a5a2f5f6b7486883a8fabd6b2e81d


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

android-nexus5X
android-nexus6

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8974256241119111552

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

Hi sunxd@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 : sunxd
  Commit : 06adb5e74eb341b5a1fa68fed4e489f6f62ec5e8
  Date   : Fri Jul 07 20:54:23 2017
  Subject: cc: Enable composited border-radius scrolling.

Bisect Details
  Configuration: android_nexus5X_perf_bisect
  Benchmark    : system_health.common_mobile
  Metric       : cpu_time_percentage_avg/browse_media/browse_media_youtube
  Change       : 6.88% | 0.374564615258 -> 0.400340256953

Revision             Result                      N
chromium@484998      0.374565 +- 0.00863919      6      good
chromium@485026      0.376482 +- 0.00610726      6      good
chromium@485033      0.376431 +- 0.00708466      6      good
chromium@485037      0.379213 +- 0.00804917      6      good
chromium@485039      0.377442 +- 0.00942156      6      good
chromium@485040      0.400218 +- 0.00951258      6      bad       <--
chromium@485053      0.396987 +- 0.00468656      6      bad
chromium@485107      0.40034 +- 0.00551673       6      bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=android-chromium --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests --story-filter=browse.media.youtube system_health.common_mobile

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8974256241119111552


For feedback, file a bug with component Speed>Bisection

This CL enables border-radius scrollers to scroll on impl. The scrolling was previously handled by blink, and now cc gets the information and handle it. I think similar to  crbug.com/741729 , the regression is also expected.