IDL: Add missing type-check for callback function arguments

Source/bindings/tests/results/core/V8TestInterface.cpp

Index: Source/bindings/tests/results/core/V8TestInterface.cpp
diff --git a/Source/bindings/tests/results/core/V8TestInterface.cpp b/Source/bindings/tests/results/core/V8TestInterface.cpp
index ee22dc2217f61d28880eb99c498d07257f850a05..ade3ea83602ed0079b3b9d934c4b88ce5ec9beb7 100644
--- a/Source/bindings/tests/results/core/V8TestInterface.cpp
+++ b/Source/bindings/tests/results/core/V8TestInterface.cpp
@@ -1540,6 +1540,10 @@ static void partialVoidMethodPartialCallbackTypeArgMethod(const v8::FunctionCall
     TestInterfaceImplementation* impl = V8TestInterface::toImpl(info.Holder());
     ScriptValue partialCallbackTypeArg;
     {
+        if (!info[0]->IsFunction()) {
+            V8ThrowException::throwTypeError(info.GetIsolate(), ExceptionMessages::failedToExecute("partialVoidMethodPartialCallbackTypeArg", "TestInterface", "The callback provided as parameter 1 is not a function."));
+            return;
+        }
         partialCallbackTypeArg = ScriptValue(ScriptState::current(info.GetIsolate()), info[0]);
     }
     TestPartialInterface::partialVoidMethodPartialCallbackTypeArg(*impl, partialCallbackTypeArg);