Restructure handling of list type extended attributes

Source/bindings/scripts/v8_attributes.py

 # Copyright (C) 2013 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 20 matching lines @@
 Extends IdlType with property |constructor_type_name|.
 
 Design doc: http://www.chromium.org/developers/design-documents/idl-compiler
 """
 
 import idl_types
 from idl_types import inherits_interface
 from v8_globals import includes, interfaces
 import v8_types
 import v8_utilities
-from v8_utilities import capitalize, cpp_name, has_extended_attribute, has_extended_attribute_value, scoped_name, strip_suffix, uncapitalize
+from v8_utilities import (capitalize, cpp_name, has_extended_attribute,
+                          has_extended_attribute_value, scoped_name, strip_suffix,
+                          uncapitalize, extended_attribute_value_as_list)
 
 
 def attribute_context(interface, attribute):
     idl_type = attribute.idl_type
     base_idl_type = idl_type.base_type
     extended_attributes = attribute.extended_attributes
 
     idl_type.add_includes_for_type()
 
     # [CheckSecurity]
@@ skipping 76 matching lines @@
         'name': attribute.name,
         'only_exposed_to_private_script': is_only_exposed_to_private_script,
         'per_context_enabled_function': v8_utilities.per_context_enabled_function_name(attribute),  # [PerContextEnabled]
         'private_script_v8_value_to_local_cpp_value': idl_type.v8_value_to_local_cpp_value(
             extended_attributes, 'v8Value', 'cppValue', isolate='scriptState->isolate()', used_in_private_script=True),
         'property_attributes': property_attributes(attribute),
         'put_forwards': 'PutForwards' in extended_attributes,
         'reflect_empty': extended_attributes.get('ReflectEmpty'),
         'reflect_invalid': extended_attributes.get('ReflectInvalid', ''),
         'reflect_missing': extended_attributes.get('ReflectMissing'),
-        'reflect_only': extended_attributes['ReflectOnly'].split('|')
-            if 'ReflectOnly' in extended_attributes else None,
+        'reflect_only': extended_attribute_value_as_list(attribute, 'ReflectOnly'),
         'runtime_enabled_function': v8_utilities.runtime_enabled_function_name(attribute),  # [RuntimeEnabled]
         'setter_callback': setter_callback_name(interface, attribute),
         'should_be_exposed_to_script': not (is_implemented_in_private_script and is_only_exposed_to_private_script),
         'world_suffixes': ['', 'ForMainWorld']
                           if 'PerWorldBindings' in extended_attributes
                           else [''],  # [PerWorldBindings]
     }
 
     if is_constructor_attribute(attribute):
         constructor_getter_context(interface, attribute, context)
@@ skipping 343 matching lines @@
     lambda self: strip_suffix(self.base_type, 'Constructor'))
 
 
 def is_constructor_attribute(attribute):
     # FIXME: replace this with [ConstructorAttribute] extended attribute
     return attribute.idl_type.name.endswith('Constructor')
 
 
 def constructor_getter_context(interface, attribute, context):
     context['needs_constructor_getter_callback'] = context['measure_as'] or context['deprecate_as']