Revert of IDL: Treat undefined as missing for optional arguments with defaults

Source/bindings/templates/methods.cpp

Index: Source/bindings/templates/methods.cpp
diff --git a/Source/bindings/templates/methods.cpp b/Source/bindings/templates/methods.cpp
index 141e5d6fc4aeba76507bcc6e9e7d6d64846d59dc..71336908ed341d74bd1d874fd74ebef9069038cb 100644
--- a/Source/bindings/templates/methods.cpp
+++ b/Source/bindings/templates/methods.cpp
@@ -70,7 +70,7 @@
     {% endif %}
     {% for argument in method.arguments %}
     {% if argument.default_value %}
-    if (!info[{{argument.index}}]->IsUndefined()) {
+    if (info.Length() > {{argument.index}}) {
         {{generate_argument(method, argument, world_suffix) | indent(8)}}
     } else {
         {{argument.name}} = {{argument.default_value}};