This test is flakily failing on the Chromium bots (see http://test-results.appspot.com/dashboards/flakiness_dashboard.html#showExpectations=true&tests=compositing%2Flayer-creation%2Fanimation-overlap-with-children.html ). Per the following conversation it'd be good to rewrite this test to not be racy:
<jamesr> looking at the test it's flaky
<jamesr> it starts a css animation
<jamesr> then stops the test when an animation event fires
<jamesr> but that could race
<pkasting> Sounds like I should file a bug marking this TEXT PASS and asking for the test to be rewritten to not be racy?
<pkasting> Any particular good assignee?
<jamesr> simon fraser wrote the test it appears