This is a breaking change as Icon.Layout no longer requests a size.
Before:
sz := unit.Dp(20)
ic.Layout(gtx, sz)
After:
sz := gtx.Metric.Px(unit.Dp(20))
gtx.Constraints.Min = image.Pt(sz, 0)
ic.Layout(gtx)
Fixes gio#240
Signed-off-by: pierre <pierre.curto@gmail.com>