Mate Welcome flickers when it starts and in its Main Menu

It almost looks like a couple of quick ligntning flashes. On the page, "It's going to be the release of 16.04 Beta 1 tomorrow" it flickers/flashes kind of like the old TVs where you have horizontal adjustment or VHS players that needed tracking adjusted.

Totally happens to me as well.

It's to do with the scrollbar appearing/disappearing very rapidly. Possibly due to the elements on the page exceeding the window size. It's less likely to happen in a maximized or larger window. I'll investigate.

Flickering shouldn't happen, it even happens when scroll bars are supposed to be hidden, indicating a possible bug with WebKit. This didn't happen in a normal web browser though.

For now, the vertical scroll bar will always stay on screen. :(
https://bitbucket.org/lah7/ubuntu-mate-welcome/commits/b1178293bcfa599737606b5a6afbee2eee6d6032?at=master

We'll keep track of this issue upstream and hammer this again later.
https://bitbucket.org/ubuntu-mate/ubuntu-mate-welcome/issues/1/minor-flickering-at-bottom-and-right

Actually, the always visible scroll bar may be reverted, since it's pretty ugly.

This flicker bug is not present in WebKit2 (gir1.2-webkit2-4.0), which we will be migrating Welcome to. The only downside is that this package is only available for Xenial. 15.10 and prior will still have the flicker with the older version of WebKit.