Here is an example of using Skia's PDF backend (SkPDF) via the SkDocument and SkCanvas APIs.
There are several corners of Skia's public API that SkPDF currently does not handle because either no known client uses the feature or there is no simple PDF-ish way to handle it.
In this document:
drop means to draw nothing.
ignore means to draw without the effect
expand means to implement something in a non-PDF-ish way. This may mean to rasterize vector graphics, to expand paths with path effects into many individual paths, or to convert text to paths.
SkImageFilter: When SkImageFilter is expanded, text-as-text is lost.
SkXferMode: The following transfer modes are not natively supported by PDF: DstOver, SrcIn, DstIn, SrcOut, DstOut, SrcATop, DstATop, and Modulate.
drawText with VerticalText — drop. No known clients seem to make use of the VerticalText flag.
drawTextOnPath — expand. (Text-as-text is lost.)
drawVertices — drop.
drawPatch — drop.