[css-transforms-1] Follow current SVG behavior for transforms interaction with object bounding box units

[smfr]

https://www.w3.org/Bugs/Public/show_bug.cgi?id=28385

[smfr]

@AmeliaBR, I wonder if you might have mis-read this paragraph in the spec:

In particular the patternUnits, gradientUnits and maskUnits attributes don’t affect the user coordinate system used for transformations [SVG11].

Note that it's talking about patternUnits, not patternTransform. I'm not sure what that paragraph is trying to say, however (maybe that patternUnits affects the rendering of the pattern, but not other things rendered in the local coordinate space of the referencing element?)

[smfr]

Duplicate of #893