Do not store gap and shift parameters on RenderMathMLFraction

[Frédéric Wang (:fredw)]

Follow-up of bug 159624. Gap and shift parameters are only used during layoutBlock so we do not need to store them on the renderer class. I'm going to split updateLayoutParameters into three helper functions: one to update thickness and two to retrieve fraction and stack parameters.

[Frédéric Wang (:fredw)]

Created attachment 283899 [details]
Patch

[Darin Adler]

Comment on attachment 283899 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=283899&action=review

> Source/WebCore/rendering/mathml/RenderMathMLFraction.cpp:125
> +        topShiftUp = bottomShiftDown = 0;

WebKit coding style normally frowns on this style of multiple assignments in a single expression.

> Source/WebCore/rendering/mathml/RenderMathMLFraction.h:63
> +    void getFractionParameters(LayoutUnit&, LayoutUnit&, LayoutUnit&, LayoutUnit&);
> +    void getStackParameters(LayoutUnit&, LayoutUnit&, LayoutUnit&);

Normally we’d include argument names in a case like this where the order of the arguments doesn’t make clear which is which. in fact, we could consider a version where these functions return structs instead, which eliminates the possibility of getting the order wrong.

[Frédéric Wang (:fredw)]

https://trac.webkit.org/changeset/203395