third_party/blink/web_tests/transitions/background-webkit-mask-crash.html

<!DOCTYPE html>
<style>
#test {
  transition: background, -webkit-mask 1s;
}
</style>
<div id="test"></div>
<p>This tests a crash that was occuring when a transition was targeting background or -webkit-mask properties on an element that did not have any style specified for those properties. This test passes if it does not crash.</p>
<script>
if (window.testRunner) {
  testRunner.dumpAsText();
  testRunner.waitUntilDone();
}
setTimeout(function() {
  test.style.backgroundColor = 'green';
  setTimeout(function() {
    if (window.testRunner)
      testRunner.notifyDone();
  }, 0);
}, 0);
</script>