LibWeb: Parse the `math-shift` and `math-style` CSS properties

Currently these have no effect, but they're simple, and `math-style`
influences `math-depth` which is coming next.

Userland/Libraries/LibWeb/CSS/ComputedValues.h

@@ -120,6 +120,9 @@ public:
     static CSS::OutlineStyle outline_style() { return CSS::OutlineStyle::None; }
     static CSS::Length outline_width() { return CSS::Length::make_px(3); }
     static CSS::TableLayout table_layout() { return CSS::TableLayout::Auto; }
+
+    static CSS::MathShift math_shift() { return CSS::MathShift::Normal; }
+    static CSS::MathStyle math_style() { return CSS::MathStyle::Normal; }
 };
 
 enum class BackgroundSize {
@@ -346,6 +349,9 @@ public:
 
     CSS::TableLayout table_layout() const { return m_noninherited.table_layout; }
 
+    CSS::MathShift math_shift() const { return m_inherited.math_shift; }
+    CSS::MathStyle math_style() const { return m_inherited.math_style; }
+
     ComputedValues clone_inherited_values() const
     {
         ComputedValues clone;
@@ -385,6 +391,9 @@ protected:
         CSS::TextAnchor text_anchor { InitialValues::text_anchor() };
 
         Vector<ShadowData> text_shadow;
+
+        CSS::MathShift math_shift { InitialValues::math_shift() };
+        CSS::MathStyle math_style { InitialValues::math_style() };
     } m_inherited;
 
     struct {
@@ -579,6 +588,9 @@ public:
     void set_outline_offset(CSS::Length value) { m_noninherited.outline_offset = value; }
     void set_outline_style(CSS::OutlineStyle value) { m_noninherited.outline_style = value; }
     void set_outline_width(CSS::Length value) { m_noninherited.outline_width = value; }
+
+    void set_math_shift(CSS::MathShift value) { m_inherited.math_shift = value; }
+    void set_math_style(CSS::MathStyle value) { m_inherited.math_style = value; }
 };
 
 }

Userland/Libraries/LibWeb/CSS/Enums.json

@@ -276,6 +276,14 @@
     "inside",
     "outside"
   ],
+  "math-shift": [
+    "normal",
+    "compact"
+  ],
+  "math-style": [
+    "normal",
+    "compact"
+  ],
   "object-fit": [
     "fill",
     "contain",

Userland/Libraries/LibWeb/CSS/Identifiers.json

@@ -105,6 +105,7 @@
   "collapse",
   "column",
   "column-reverse",
+  "compact",
   "condensed",
   "contain",
   "content",

Userland/Libraries/LibWeb/CSS/Properties.json

@@ -1479,6 +1479,20 @@
       "unitless-length"
     ]
   },
+  "math-shift": {
+    "inherited": true,
+    "initial": "normal",
+    "valid-types": [
+      "math-shift"
+    ]
+  },
+  "math-style": {
+    "inherited": true,
+    "initial": "normal",
+    "valid-types": [
+      "math-style"
+    ]
+  },
   "max-height": {
     "inherited": false,
     "initial": "none",

Userland/Libraries/LibWeb/Layout/Node.cpp

@@ -789,6 +789,14 @@ void NodeWithStyle::apply_style(const CSS::StyleProperties& computed_style)
         transfer_table_box_computed_values_to_wrapper_computed_values(wrapper_computed_values);
     }
 
+    auto math_shift_value = computed_style.property(CSS::PropertyID::MathShift);
+    if (auto math_shift = value_id_to_math_shift(math_shift_value->to_identifier()); math_shift.has_value())
+        computed_values.set_math_shift(math_shift.value());
+
+    auto math_style_value = computed_style.property(CSS::PropertyID::MathStyle);
+    if (auto math_style = value_id_to_math_style(math_style_value->to_identifier()); math_style.has_value())
+        computed_values.set_math_style(math_style.value());
+
     // Update any anonymous children that inherit from this node.
     // FIXME: This is pretty hackish. It would be nicer if they shared the inherited style
     //        data structure somehow, so this wasn't necessary.