Math tag is not exposed in Accessibility.

Source/modules/accessibility/AXRenderObject.cpp

Index: Source/modules/accessibility/AXRenderObject.cpp
diff --git a/Source/modules/accessibility/AXRenderObject.cpp b/Source/modules/accessibility/AXRenderObject.cpp
index f262d7b35daa23ee55f6fa83987a6fff6de7a295..628f4e693cb32ce0dbdd97fc14ca003658fba5d2 100644
--- a/Source/modules/accessibility/AXRenderObject.cpp
+++ b/Source/modules/accessibility/AXRenderObject.cpp
@@ -368,6 +368,9 @@ AccessibilityRole AXRenderObject::determineAccessibilityRole()
     if (node && node->hasTagName(dtTag))
         return DescriptionListTermRole;
 
+    if (node && (node->nodeName() == "math"))
+        return MathRole;
+
     if (node && (node->hasTagName(rpTag) || node->hasTagName(rtTag)))
         return AnnotationRole;
 
@@ -736,6 +739,9 @@ bool AXRenderObject::computeAccessibilityIsIgnored() const
     if (roleValue() == DetailsRole)
         return false;
 
+    if (roleValue() == MathRole)
+        return false;
+
     if (roleValue() == MeterRole)
         return false;