Chrome Version: 65.0.3325.9
OS: ChromeOS

What steps will reproduce the problem?
(1) Open a web site that contains links that will open in a new tab, e.g. GMail.
(2) Click on one of the links.
(3) Watch the tab spinner while the new tab is opening.

What is the expected result?

Expect that the spinner animates smoothly.

What happens instead?

Spinner often (seems dependent on the site, or possibly just on how long it takes to load) animates at a lower-than-normal frame rate - this looks like issues we've had previously with the compositor "timing out" waiting for a renderer to provide a suitable frame.

I hit a similar issue recently, also on ChromeOS, where the desktop wallpaper on one monitor had stayed blurred after unlocking the workstation, and doing anything which caused the single window on that monitor to be re-composited caused things to be janky. e.g. if I dragged a second window, wholly obscuring the original one, then things were smooth, but if any of the original window was visible then the frame rate would drop to this janky-looking level.

I'm also able to repro the spinner jank by just opening chromium-reviews in a new tab, FWIW.