[SVG] Fix CSS transform handling when zoomed

[Ryosuke Niwa]

Consider merging https://chromium.googlesource.com/chromium/blink/+/12e43b6d16005ed322d97e77e2ec72b0b9d40f9a

CSS takes the page zoom factor into account for all computed length
values, including transform translation components.

OTOH, SVG applies the zoom factor globally (at the SVG root level) -
so when using CSS transforms in SVG, the translation components are
scaled twice.

This CL adjusts CSS transforms when used in SVG to account for
the unexpected translation scale.

[Adenilson Cavalcanti Silva]

Created attachment 228868 [details]
Patch

[Tim Horton]

Comment on attachment 228868 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=228868&action=review

> Source/WebCore/svg/SVGGraphicsElement.cpp:80
> +        float zoom = style->effectiveZoom();

does this take page scale into account? page zoom? which ones are baked into the CSS transform values?

[WebKit Commit Bot]

Comment on attachment 228868 [details]
Patch

Clearing flags on attachment: 228868

Committed r166967: <http://trac.webkit.org/changeset/166967>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.