bindings: Supports [LenientThis] 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 107 matching lines @@
         'is_check_security_for_frame': is_check_security_for_frame,
         'is_check_security_for_node': is_check_security_for_node,
         'is_check_security_for_window': is_check_security_for_window,
         'is_custom_element_callbacks': is_custom_element_callbacks,
         'is_expose_js_accessors': is_expose_js_accessors(interface, attribute),
         'is_getter_raises_exception':  # [RaisesException]
             'RaisesException' in extended_attributes and
             extended_attributes['RaisesException'] in (None, 'Getter'),
         'is_implemented_in_private_script': is_implemented_in_private_script,
         'is_keep_alive_for_gc': keep_alive_for_gc,
+        '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_static': attribute.is_static,
@@ skipping 70 matching lines @@
     def v8_set_return_value_statement(for_main_world=False):
         if context['is_keep_alive_for_gc'] or 'CachedAttribute' in extended_attributes:
             return 'v8SetReturnValue(info, v8Value)'
         return idl_type.v8_set_return_value(
             cpp_value, extended_attributes=extended_attributes, script_wrappable='impl',
             release=release, for_main_world=for_main_world, is_static=attribute.is_static)
 
     context.update({
         'cpp_value': cpp_value,
         'cpp_value_to_v8_value': idl_type.cpp_value_to_v8_value(
-            cpp_value=cpp_value, creation_context='info.Holder()',
+            cpp_value=cpp_value, creation_context='holder',
             extended_attributes=extended_attributes),
         'v8_set_return_value_for_main_world': v8_set_return_value_statement(for_main_world=True),
         'v8_set_return_value': v8_set_return_value_statement(),
     })
 
 def getter_expression(interface, attribute, context):
     arguments = []
     this_getter_base_name = getter_base_name(interface, attribute, arguments)
     getter_name = scoped_name(interface, attribute, this_getter_base_name)
 
@@ skipping 310 matching lines @@
     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']
     # When the attribute name is the same as the interface name, do not generate
     # callback functions for each attribute and use
     # {{cpp_class}}ConstructorAttributeSetterCallback.  Otherwise, generate
     # a callback function in order to hard-code the attribute name.
     context['needs_constructor_setter_callback'] = context['name'] != context['constructor_type']