Bug 1610245 [wpt PR 21257] - Add tests for baseline, stretchiness and…

… spacing in unknown elements., a=testonly

Automatic update from web-platform-tests
Add tests for baseline, stretchiness and spacing in unknown elements. (#21257)

See https://github.com/mathml-refresh/mathml/issues/139

This also fixes wrong mpaddednotation attribute and repeats spacing tests
for other mrow-like elements.
--

wpt-commits: 87646d626a9a84941e790da383f140df6b37279d
wpt-pr: 21257

UltraBlame original commit: 3a5ca745a2b258b0d6682ed347be800d9490885c

testing/web-platform/tests/mathml/presentation-markup/mrow/inferred-mrow-baseline.html

@@ -457,6 +457,9 @@
 "
 Mpadded
 "
+"
+Unknown
+"
 ]
 .
 forEach
@@ -1095,10 +1098,10 @@
 >
 <
 mpadded
-notation
+lspace
 =
 "
-box
+10px
 "
 >
 <
@@ -1168,6 +1171,78 @@
 math
 >
 <
+math
+>
+<
+unknown
+>
+<
+mspace
+id
+=
+"
+aboveUnknown
+"
+width
+=
+"
+10px
+"
+height
+=
+"
+30px
+"
+style
+=
+"
+background
+:
+purple
+"
+>
+<
+/
+mspace
+>
+<
+mspace
+id
+=
+"
+belowUnknown
+"
+width
+=
+"
+10px
+"
+depth
+=
+"
+30px
+"
+style
+=
+"
+background
+:
+blue
+"
+>
+<
+/
+mspace
+>
+<
+/
+unknown
+>
+<
+/
+math
+>
+<
 /
 p
 >

testing/web-platform/tests/mathml/presentation-markup/mrow/inferred-mrow-stretchy.html

@@ -568,6 +568,9 @@
 "
 Mpadded
 "
+"
+Unknown
+"
 ]
 .
 forEach
@@ -1052,10 +1055,10 @@
 >
 <
 mpadded
-notation
+lspace
 =
 "
-box
+10px
 "
 >
 <
@@ -1107,6 +1110,60 @@
 math
 >
 <
+math
+>
+<
+unknown
+>
+<
+mo
+id
+=
+"
+moUnknown
+"
+>
+&
+#
+x21A8
+;
+<
+/
+mo
+>
+<
+mspace
+width
+=
+"
+1px
+"
+height
+=
+"
+100px
+"
+style
+=
+"
+background
+:
+magenta
+"
+>
+<
+/
+mspace
+>
+<
+/
+unknown
+>
+<
+/
+math
+>
+<
 /
 p
 >