Grid component layout fix introduced in 8.25.0 can cause slowdown

[thevaadinman]

Vaadin 8.25.0 introduced a fix for a situation where a Grid containing layout components in its cells would cause the layout to break. This was fixed by forcing a layout recalculation after every scroll event.
This, in turn, can introduce noticable slowdown in complex UIs.

This ticket is here to track optimization efforts, and for users to report their experiences.

[TatuLund]

This is improved in Vaadin 8.25.2 released today.