Added enum checks since enums are now supported in the IDL

Source/bindings/dart/scripts/dart_dictionary.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Generate template contexts of dictionaries for both v8 bindings and
 implementation classes that are used by blink's core/modules.
 """
 
 import operator
 from v8_globals import includes
@@ skipping 54 matching lines @@
         if member.default_value.is_null:
             return None, 'v8::Null(isolate)'
         cpp_default_value = str(member.default_value)
         v8_default_value = idl_type.cpp_value_to_v8_value(
             cpp_value=cpp_default_value, isolate='isolate',
             creation_context='creationContext')
         return cpp_default_value, v8_default_value
 
     cpp_default_value, dart_default_value = default_values()
 
+    dart_enum_expression = idl_type.enum_validation_expression
+    if dart_enum_expression:
+        dart_enum_expression = dart_enum_expression.format(param_name='string')
+
     return {
         'cpp_default_value': cpp_default_value,
         'cpp_type': idl_type.cpp_type,
         'cpp_value_to_dart_value': idl_type.cpp_value_to_dart_value(
             cpp_value='impl->%s()' % member.name,
             creation_context='creationContext',
             extended_attributes=member.extended_attributes),
-        'enum_validation_expression': idl_type.enum_validation_expression,
+        'enum_validation_expression': dart_enum_expression,
         'has_method_name': has_method_name_for_dictionary_member(member),
         'is_object': idl_type.name == 'Object',
         'name': member.name,
         'setter_name': setter_name_for_dictionary_member(member),
         'dart_default_value': dart_default_value,
     }
 
 
 # Context for implementation classes
 
@@ skipping 43 matching lines @@
         'has_method_expression': has_method_expression(),
         'has_method_name': has_method_name_for_dictionary_member(member),
         'is_object': is_object,
         'is_traceable': (idl_type.is_garbage_collected or
                          idl_type.is_will_be_garbage_collected),
         'member_cpp_type': member_cpp_type(),
         'name': member.name,
         'rvalue_cpp_type': idl_type.cpp_type_args(used_as_rvalue_type=True),
         'setter_name': setter_name_for_dictionary_member(member),
     }