It does not represent `<length> | <percentage>`, but `<length-percentage>`, so
`LengthOrPercentage` is not the right name.
This patch is totally autogenerated using:
rg 'LengthOrPercentage' servo | cut -d : -f 1 | sort | uniq > files
for file in $(cat files); do sed -i "s#LengthOrPercentage#LengthPercentage#g" $file; done
Differential Revision: https://phabricator.services.mozilla.com/D15812
Replace LengthOrPercentage with NonNegativeLengthOrPercentage on
ShapeRadius, Circle, Ellipse. And derive ToAnimatedValue for ShapeSource and
its related types, so we clamp its interpolated results into non-negative
values. (i.e. The radius of circle()/ellipse() and the border-radius of
inset().)
Note: We may get negative values when using a negative easing function, so the
clamp is necessary to avoid the incorrect result or any undefined behavior.
Differential Revision: https://phabricator.services.mozilla.com/D14654
