external/wpt/event-timing/programmatic-click-not-observed.html is flaky

No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 961547

Change-Id: Ia5adbbb01b3ad4dad4b98e5a72bb76bf6fa94173
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1605283Reviewed-by: Noel Gordon <noel@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#658385}

third_party/blink/web_tests/TestExpectations

@@ -5971,3 +5971,6 @@ crbug.com/959129 [ Win ] http/tests/devtools/tracing/timeline-script-parse.js [
 
 # Sheriff 2019-05-07
 crbug.com/960443 [ Mac10.10 Mac10.11 ] external/wpt/animation-worklet/worklet-animation-with-scroll-timeline.https.html [ Failure Pass ]
+
+# Sheriff 2019-05-07
+crbug.com/961547 external/wpt/event-timing/programmatic-click-not-observed.html [ Pass Failure ]