[Sheriff] Mark...

[Sheriff] Mark virtual/threaded-no-composited-antialiasing/animations/events/animation-iteration-event.html as flaky

TBR=apotapchuk@chromium.org

No-Try: true
Bug: 1066122
Change-Id: I4949697cbf0aa4105279a08580187d367f6a861e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2130587
Commit-Queue: Hiroshige Hayashizaki <hiroshige@chromium.org>
Reviewed-by: Hiroshige Hayashizaki <hiroshige@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755243}

third_party/blink/web_tests/TestExpectations

@@ -6652,6 +6652,8 @@ crbug.com/1064839 fast/hidpi/image-srcset-svg-canvas.html [ Pass Failure ]
 crbug.com/1065335 [ Win ] fast/hidpi/image-srcset-relative-svg-canvas.html [ Pass Failure ]
 # Sheriff 2020-03-31
 crbug.com/1065335 [ Win ] fast/hidpi/image-srcset-relative-svg-canvas-2x.html [ Pass Failure ]
+# Sheriff 2020-04-01
+crbug.com/1066122 virtual/threaded-no-composited-antialiasing/animations/events/animation-iteration-event.html [ Pass Failure ]
 
 # TODO(danakj): Rebaseline for Mac 10.14
 crbug.com/1066392 [ Mac ] virtual/gpu-rasterization/images/ycbcr-with-cmyk-color-profile.html [ Pass Failure ]