Support transform-box to switch sizing box in SVG

[Dirk Schulze]

transform-box was added to CSS Transforms to allow the user to switch between the objectBoundingBox and the SVG viewport for computing the transform origin and the reference dimension for transforms with percentage.

http://dev.w3.org/csswg/css-transforms/#transform-box

[Fredrik Söderquist]

Gecko is set to ship this in version 55, and an implementation will land in Blink shortly. It'd be good to have some feedback from WebKit, especially wrt https://github.com/w3c/csswg-drafts/issues/857.

[Simon Fraser (smfr)]

*** Bug 171023 has been marked as a duplicate of this bug. ***

[Simon Fraser (smfr)]

Following https://github.com/w3c/csswg-drafts/issues/928, implementing transform-box will be a behavior change. Percentage values in transform-origin and transforms will no longer resolve against the fill-box by default, but instead use view-box.

[Simon Fraser (smfr)]

Created attachment 310781 [details]
Patch

[Simon Fraser (smfr)]

Created attachment 310790 [details]
Patch

[Dean Jackson]

Comment on attachment 310790 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=310790&action=review

> Source/WebCore/css/CSSProperties.json:5963
> +            "codegen-properties": {
> +            },

Remove?

> Source/WebCore/rendering/style/RenderStyle.cpp:1134
> +    FloatPoint3D originTranslate;

originTranslation? You're nouning a verb :)

[WebKit Commit Bot]

Comment on attachment 310790 [details]
Patch

Clearing flags on attachment: 310790

Committed r217236: <http://trac.webkit.org/changeset/217236>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/32332230>