Refactor RenderMathMLSpace to avoid using flexbox

[Frédéric Wang (:fredw)]

To prepare for bug 153991, let's do as in other classes and implement RenderMathMLSpace::computePreferredLogicalWidths, RenderMathMLSpace::layoutBlock and RenderMathMLSpace::firstLineBaseline

[Frédéric Wang (:fredw)]

Created attachment 273293 [details]
Patch

[Frédéric Wang (:fredw)]

Created attachment 273707 [details]
Patch

I'm uploading updated version of the MathML refactoring patches to solve conflicts after bug 154388 and bug 155005 ; and to do other minor changes.

[Frédéric Wang (:fredw)]

Created attachment 275291 [details]
Patch

[Martin Robinson]

Comment on attachment 275291 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=275291&action=review

> LayoutTests/ChangeLog:8
> +        * mathml/presentation/mspace-prefered-width-expected.html: Update the expectation so that the logical width and preferred width are both equal to the one specified by the width attribute.

Please break lines at 100 characters.

> Source/WebCore/ChangeLog:8
> +        No new tests, already covered by existing tests. The behavior of mspace-prefered-width-expected is not specified by the MathML recommendation, we update that test to match our new behavior.

Ditto.

[Frédéric Wang (:fredw)]

Created attachment 276819 [details]
Patch

Rebasing patch.

[Frédéric Wang (:fredw)]

Removing dependencies as we don't really have to wait for bug 155018/155019 to take this patch.

[Frédéric Wang (:fredw)]

Committed r199771: <http://trac.webkit.org/changeset/199771>