LibWeb: Support implicit downcast to DOMException in ExceptionOr

Libraries/LibWeb/Geometry/DOMPointReadOnly.cpp

@@ -9,6 +9,7 @@
 #include <LibWeb/Bindings/DOMPointReadOnlyPrototype.h>
 #include <LibWeb/Bindings/Intrinsics.h>
 #include <LibWeb/Geometry/DOMMatrix.h>
+#include <LibWeb/Geometry/DOMPoint.h>
 #include <LibWeb/Geometry/DOMPointReadOnly.h>
 #include <LibWeb/HTML/StructuredSerialize.h>
 #include <LibWeb/WebIDL/ExceptionOr.h>

Libraries/LibWeb/WebIDL/ExceptionOr.h

@@ -91,6 +91,13 @@ public:
     ExceptionOr(ExceptionOr const& other) = default;
     ~ExceptionOr() = default;
 
+    template<typename E>
+    requires(IsBaseOf<DOMException, E>)
+    ExceptionOr(GC::Ref<E> exception)
+        : ExceptionOr(GC::Ref<DOMException> { exception })
+    {
+    }
+
     ValueType& value()
     requires(!IsSame<ValueType, Empty>)
     {