All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=752064

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=ed631c9df85ad9041719bd7dc6e864a981466bcff60ab2b4a131a82952608cdb


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

android-webview-nexus6
chromium-rel-mac-retina
chromium-rel-mac11
chromium-rel-mac11-air
chromium-rel-mac11-pro
chromium-rel-mac12
chromium-rel-win7-dual
chromium-rel-win7-gpu-nvidia
chromium-rel-win7-x64-dual
chromium-rel-win8-dual

Started bisect job https://chromeperf.appspot.com/buildbucket_job_status/8972283056085827744

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

Hi xidachen@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 : Xida Chen
  Commit : 07ca939ed0a0f50c871809e8c2d8245c50713142
  Date   : Fri Jul 28 01:48:24 2017
  Subject: Improve performance of WebLayerImpl::SetTouchEventHandlerRegion

Bisect Details
  Configuration: win_x64_perf_bisect
  Benchmark    : speedometer
  Metric       : VanillaJS-TodoMVC/VanillaJS-TodoMVC
  Change       : 1.53% | 221.6855 -> 218.292583333

Revision             Result                  N
chromium@490056      221.686 +- 12.0186      9       good
chromium@490137      220.675 +- 1.05645      6       good
chromium@490178      222.0 +- 5.93842        14      good
chromium@490188      222.82 +- 5.45029       9       good
chromium@490192      222.701 +- 3.12326      9       good
chromium@490193      221.594 +- 7.62219      14      good
chromium@490194      219.152 +- 4.38269      9       bad       <--
chromium@490196      220.061 +- 7.13468      14      bad
chromium@490218      218.293 +- 1.98625      6       bad

To Run This Test
  src/tools/perf/run_benchmark -v --browser=release_x64 --output-format=chartjson --upload-results --pageset-repeat=1 --also-run-disabled-tests speedometer

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

Debug information about this bisect:
  https://chromeperf.appspot.com/buildbucket_job_status/8972283056085827744


For feedback, file a bug with component Speed>Bisection

In the CL, we are adding some additional steps to send extra info from blink-->cc, for optimization of touch action. So this is a necessary step.