All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=908558

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=3e6a302b4b3eddd72052613b1df396d2f8d1053b2b215ddbe687d131933517fd


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

linux-perf
mac-10_12_laptop_low_end-perf
mac-10_13_laptop_high_end-perf

system_health.common_desktop - Benchmark documentation link:
  https://bit.ly/system-health-benchmarks

power.desktop - Benchmark documentation link:
  https://bit.ly/power-benchmarks

rendering.desktop - Benchmark documentation link:
  https://bit.ly/rendering-benchmarks

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/1016bd38140000

📍 Found a significant difference after 1 commit.
https://pinpoint-dot-chromeperf.appspot.com/job/1016bd38140000

Fix perf regression of PassiveDocumentWheelEventListeners. by sahel@chromium.org
https://chromium.googlesource.com/chromium/src/+/19a66a429489c8eb9fec304198548c18de59e5d2
frame_times: 29.13 → 47.5 (+18.37)

Understanding performance regressions:
  http://g.co/ChromePerformanceRegressions

Benchmark documentation link:
  https://bit.ly/rendering-benchmarks

The suspected cl only changes the "js_scroll_200_layer_grid" and 
"js_scroll_text_only" tests. These to tests add event listeners to prevent default wheel and touch events and call js scrolling instead. The change is necessary since the added event listeners used to call prevent default without must specifying "passive:false".