Use dynamicDowncast<T> in AccessibilityARIAGridRow.cpp

https://bugs.webkit.org/show_bug.cgi?id=267146

Reviewed by Chris Dumez.

Canonical link: https://commits.webkit.org/272824@main

Source/WebCore/accessibility/AccessibilityARIAGridRow.cpp

@@ -71,7 +71,7 @@ AXCoreObject::AccessibilityChildrenVector AccessibilityARIAGridRow::disclosedRow
     // The contiguous disclosed rows will be the rows in the table that 
     // have an aria-level of plus 1 from this row.
     AccessibilityObject* parent = parentObjectUnignored();
-    if (!is<AccessibilityTable>(*parent) || !downcast<AccessibilityTable>(*parent).isExposable())
+    if (auto* axTable = dynamicDowncast<AccessibilityTable>(*parent); !axTable || !axTable->isExposable())
         return disclosedRows;
 
     // Search for rows that match the correct level. 
@@ -100,7 +100,7 @@ AXCoreObject* AccessibilityARIAGridRow::disclosedByRow() const
     // The row that discloses this one is the row in the table
     // that is aria-level subtract 1 from this row.
     AccessibilityObject* parent = parentObjectUnignored();
-    if (!is<AccessibilityTable>(*parent) || !downcast<AccessibilityTable>(*parent).isExposable())
+    if (auto* axTable = dynamicDowncast<AccessibilityTable>(*parent); !axTable || !axTable->isExposable())
         return nullptr;
 
     // If the level is 1 or less, than nothing discloses this row.
@@ -138,10 +138,8 @@ AccessibilityTable* AccessibilityARIAGridRow::parentTable() const
     return downcast<AccessibilityTable>(Accessibility::findAncestor<AccessibilityObject>(*this, false, [this] (const auto& ancestor) {
         // The parent table for an ARIA grid row should be an ARIA table.
         // Unless the row is a native tr element.
-        if (is<AccessibilityTable>(ancestor)) {
-            auto& ancestorTable = downcast<AccessibilityTable>(ancestor);
-            return ancestorTable.isExposable() && (ancestorTable.isAriaTable() || node()->hasTagName(HTMLNames::trTag));
-        }
+        if (auto* ancestorTable = dynamicDowncast<AccessibilityTable>(ancestor))
+            return ancestorTable->isExposable() && (ancestorTable->isAriaTable() || node()->hasTagName(HTMLNames::trTag));
 
         return false;
     }));