Chrome Version: 68.0.3428.0

What steps will reproduce the problem?
(1) Add a slow wheel listener to a page
document.body.addEventListener('wheel', function(e) {
  /* Do something that takes a long time */
})
(2) Open chrome://tracing/ in a separate tab
(3) Click the Record button
(4) Select Input latency
(5) Click the Record button
(6) Switch back to the tab with the slow wheel listener
(7) Scroll the page with the mouse wheel
(8) Switch back to the tracing tab
(9) Stop the recording
(10) Examine InputLatency::MouseWheel

What is the expected result?
All of the MouseWheel entries should be properly terminated

What happens instead?
There are unterminated MouseWheel entries (indicated by "Did Not Finish").