Unfortunately we can't port these functions entirely over to FlyString
from DeprecatedString as Document includes NonElementParentNode and has
not yet been ported over to new AK string. In the mean time, this should
help up in porting over NonElementParentNode itself.
This implements the stop-opacity, fill-opacity, and stroke-opacity
properties (in CSS). This replaces the existing more ad-hoc
fill-opacity attribute handling.
This is the base class for all SVG gradient types. This supports:
- The `gradientUnits` attribute
- The `gradientTransform` attribute
- And following `xlink:hrefs` for inheriting <stops>/attributes