Extend ScalarValueString handling to include constructors.

Source/bindings/scripts/v8_methods.py

Index: Source/bindings/scripts/v8_methods.py
diff --git a/Source/bindings/scripts/v8_methods.py b/Source/bindings/scripts/v8_methods.py
index 11486410b0fdec1d800890519d5f5791f8587455..eed36f1a16cc50724a8c948dede594805da8758b 100644
--- a/Source/bindings/scripts/v8_methods.py
+++ b/Source/bindings/scripts/v8_methods.py
@@ -131,10 +131,8 @@ def generate_method(interface, method):
             is_raises_exception or
             is_check_security_for_frame or
             any(argument for argument in arguments
-                if argument.idl_type.name in ('ByteString',
-                                              'ScalarValueString',
-                                              'SerializedScriptValue') or
-                   argument.idl_type.is_integer_type),
+                if argument.idl_type.name == 'SerializedScriptValue' or
+                   argument.idl_type.may_raise_exception_on_conversion),
         'idl_type': idl_type.base_type,
         'is_call_with_execution_context': has_extended_attribute_value(method, 'CallWith', 'ExecutionContext'),
         'is_call_with_script_arguments': is_call_with_script_arguments,
@@ -313,7 +311,7 @@ def v8_value_to_local_cpp_value(argument, index):
     # FIXME: This special way of handling string arguments with null defaults
     # can go away once we fully support default values.
     if (argument.is_optional and
-        idl_type.name in ('String', 'ByteString', 'ScalarValueString') and
+        idl_type.is_string_type and
         argument.default_value and argument.default_value.is_null):
         v8_value = 'argumentOrNull(info, %s)' % index
     else: