WebEngine smooth-scrolling is jittery

Tested in both QuteBrowser and Qupzilla. The Webengine backend with smooth scrolling enabled is jittery while scrolling, except for scrolling a page in a html frame.

From the Qutebrowser Github issue:

qutebrowser v0.9.0
Git commit: v0.8.0-2066-g282180e76 (2017-01-08 00:21:57 +0000)
Backend: Webengine

To replicate:

• Open Qutebrowser with `--backend webengine`
• Enable smooth scrolling (`:set ui smooth-scrolling true`)
• Scrolling this example webpage will be very jittery and not smooth at all.
• However, if that webpage is within a html frame, then scrolling the page is very smooth.

Also, I added to that issue in a later comment:

Hmm, I find on `qute://help/settings.html` that the jittering stops if I `:set tabs show never`. Other websites, like store.steampowered.com are also smoother when scrolling, but still jittery.

The example webpage is still jittery when scrolling however.

Update: Hiding the statusbar too completely eliminates all scroll-jittering on all webpages for me.

EDIT: Additionally to note, I'm running the proprietary NVidia drivers.