[MathML] Baseline wrong for fractions or munder/mover with padding
https://bugs.webkit.org/show_bug.cgi?id=97990

Reviewed by Eric Seidel.

Source/WebCore: 

We include any border or padding in our baseline computation. We also take this opportunity
to quit adding extra left & right padding to numerators and denominators, making our output
tighter and also more compatible with Firefox and TeX, since we are rebaselining some
fraction pixel tests now anyway.

Tests added to LayoutTests/mathml/presentation/{over,row-alignment}.xhtml

* rendering/mathml/RenderMathMLFraction.cpp:
(WebCore::RenderMathMLFraction::fixChildStyle):
(WebCore::RenderMathMLFraction::paint):
(WebCore::RenderMathMLFraction::firstLineBoxBaseline):
* rendering/mathml/RenderMathMLUnderOver.cpp:
(WebCore::RenderMathMLUnderOver::firstLineBoxBaseline):

LayoutTests: 

We handle any border and padding correctly, and quit adding extra left and right padding
to numerators and denominators.

* mathml/presentation/over.xhtml:
* mathml/presentation/row-alignment.xhtml:
* platform/efl/TestExpectations:
* platform/gtk/TestExpectations:
* platform/mac/mathml/presentation/attributes-expected.png:
* platform/mac/mathml/presentation/attributes-expected.txt:
* platform/mac/mathml/presentation/fractions-expected.png:
* platform/mac/mathml/presentation/fractions-expected.txt:
* platform/mac/mathml/presentation/fractions-vertical-alignment-expected.png:
* platform/mac/mathml/presentation/fractions-vertical-alignment-expected.txt:
* platform/mac/mathml/presentation/mo-stretch-expected.png:
* platform/mac/mathml/presentation/mo-stretch-expected.txt:
* platform/mac/mathml/presentation/over-expected.png:
* platform/mac/mathml/presentation/over-expected.txt:
* platform/mac/mathml/presentation/roots-expected.png:
* platform/mac/mathml/presentation/roots-expected.txt:
* platform/mac/mathml/presentation/row-alignment-expected.png:
* platform/mac/mathml/presentation/row-alignment-expected.txt:
* platform/mac/mathml/presentation/subsup-expected.png:
* platform/mac/mathml/presentation/subsup-expected.txt:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk/LayoutTests@130097 268f45cc-cd09-0410-ab3c-d52691b4dbfc