bindings: Supports [SaveSameObject] extended attribute.

third_party/WebKit/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 117 matching lines @@
         'is_lenient_this': 'LenientThis' in extended_attributes,
         'is_nullable': idl_type.is_nullable,
         'is_explicit_nullable': idl_type.is_explicit_nullable,
         'is_partial_interface_member':
             'PartialInterfaceImplementedAs' in extended_attributes,
         'is_per_world_bindings': 'PerWorldBindings' in extended_attributes,
         'is_put_forwards': 'PutForwards' in extended_attributes,
         'is_read_only': attribute.is_read_only,
         'is_reflect': is_reflect,
         'is_replaceable': 'Replaceable' in attribute.extended_attributes,
+        'is_save_same_object': (
+            'SameObject' in attribute.extended_attributes and
+            'SaveSameObject' in attribute.extended_attributes),
         'is_static': attribute.is_static,
         'is_url': 'URL' in extended_attributes,
         'is_unforgeable': is_unforgeable(interface, attribute),
         'on_instance': v8_utilities.on_instance(interface, attribute),
         'on_interface': v8_utilities.on_interface(interface, attribute),
         'on_prototype': v8_utilities.on_prototype(interface, attribute),
         'origin_trial_enabled_function': v8_utilities.origin_trial_enabled_function_name(attribute),  # [OriginTrialEnabled]
         'use_output_parameter_for_result': idl_type.use_output_parameter_for_result,
         'measure_as': v8_utilities.measure_as(attribute, interface),  # [MeasureAs]
         'name': attribute.name,
@@ skipping 395 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 update_constructor_attribute_context(interface, attribute, context):
     context['needs_constructor_getter_callback'] = context['measure_as'] or context['deprecate_as'] or context['origin_trial_enabled_function']  # TODO(chasej): Should/can this be true when OriginTrialEnabled is inherited from containing interface?