bindings: Throw TypeError when required dictionary member is undefined

Source/bindings/scripts/v8_dictionary.py

Index: Source/bindings/scripts/v8_dictionary.py
diff --git a/Source/bindings/scripts/v8_dictionary.py b/Source/bindings/scripts/v8_dictionary.py
index 1d1f2f435ff71e159d91b6a0e3c97bbe355b78cf..45de469ccc9a0cc61ba054fa7f1e0becb796cbfc 100644
--- a/Source/bindings/scripts/v8_dictionary.py
+++ b/Source/bindings/scripts/v8_dictionary.py
@@ -80,6 +80,10 @@ def member_context(dictionary, member):
     idl_type.add_includes_for_type()
     unwrapped_idl_type = unwrap_nullable_if_needed(idl_type)
 
+    if member.is_required and member.default_value:
+        raise Exception(
+            'Required member %s must not have a default value.' % member.name)
+
     def default_values():
         if not member.default_value:
             return None, None
@@ -110,6 +114,7 @@ def member_context(dictionary, member):
         'is_interface_type': idl_type.is_interface_type and not idl_type.is_dictionary,
         'is_nullable': idl_type.is_nullable,
         'is_object': unwrapped_idl_type.name == 'Object',
+        'is_required': member.is_required,
         'name': member.name,
         'setter_name': setter_name_for_dictionary_member(member),
         'null_setter_name': null_setter_name_for_dictionary_member(member),