[bindings] Implement an ExperimentEnabled IDL 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 80 matching lines @@
 
     conditional_string = v8_utilities.conditional_string(attribute)
     if conditional_string:
         includes.add('wtf/build_config.h')
 
     cached_attribute_validation_method = extended_attributes.get('CachedAttribute')
     keep_alive_for_gc = is_keep_alive_for_gc(interface, attribute)
     if cached_attribute_validation_method or keep_alive_for_gc:
         includes.add('bindings/core/v8/V8HiddenValue.h')
 
+    if 'APIExperimentEnabled' in extended_attributes:
+        includes.add('core/experiments/ExperimentalFeatures.h')
+        includes.add('core/inspector/ConsoleMessage.h')
+
     context = {
         'access_control_list': access_control_list(interface, attribute),
         'activity_logging_world_list_for_getter': v8_utilities.activity_logging_world_list(attribute, 'Getter'),  # [ActivityLogging]
         'activity_logging_world_list_for_setter': v8_utilities.activity_logging_world_list(attribute, 'Setter'),  # [ActivityLogging]
         'activity_logging_world_check': v8_utilities.activity_logging_world_check(attribute),  # [ActivityLogging]
+        'api_experiment_enabled': v8_utilities.api_experiment_enabled_function(attribute),  # [APIExperimentEnabled]
+        'api_experiment_enabled_per_interface': v8_utilities.api_experiment_enabled_function(interface),  # [APIExperimentEnabled]
+        'api_experiment_name': extended_attributes.get('APIExperimentEnabled'),  # [APIExperimentEnabled]
         'argument_cpp_type': idl_type.cpp_type_args(used_as_rvalue_type=True),
         'cached_attribute_validation_method': cached_attribute_validation_method,
         'conditional_string': conditional_string,
         'constructor_type': constructor_type,
         'cpp_name': cpp_name(attribute),
         'cpp_type': idl_type.cpp_type,
         'cpp_type_initializer': idl_type.cpp_type_initializer,
         'deprecate_as': v8_utilities.deprecate_as(attribute),  # [DeprecateAs]
         'enum_type': idl_type.enum_type,
         'enum_values': idl_type.enum_values,
         'exposed_test': v8_utilities.exposed(attribute, interface),  # [Exposed]
         'has_custom_getter': has_custom_getter(attribute),
         'has_custom_setter': has_custom_setter(attribute),
         'has_setter': has_setter(attribute),
         'idl_type': str(idl_type),  # need trailing [] on array for Dictionary::ConversionContext::setConversionType
+        'is_api_experiment_enabled': v8_utilities.api_experiment_enabled_function(attribute) or v8_utilities.api_experiment_enabled_function(interface),  # [APIExperimentEnabled]
         'is_call_with_execution_context': has_extended_attribute_value(attribute, 'CallWith', 'ExecutionContext'),
         'is_call_with_script_state': has_extended_attribute_value(attribute, 'CallWith', 'ScriptState'),
         'is_check_security_for_receiver': is_check_security_for_receiver,
         'is_check_security_for_return_value': is_check_security_for_return_value,
         'is_custom_element_callbacks': is_custom_element_callbacks,
         # TODO(yukishiino): Make all DOM attributes accessor-type properties.
         'is_data_type_property': constructor_type or interface.name == 'Window' or interface.name == 'Location',
         'is_getter_raises_exception':  # [RaisesException]
             'RaisesException' in extended_attributes and
             extended_attributes['RaisesException'] in (None, 'Getter'),
@@ skipping 371 matching lines @@
     # FIXME: replace this with a [ConstructorAttribute] extended attribute
     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']
+    context['needs_constructor_getter_callback'] = context['measure_as'] or context['deprecate_as'] or context['api_experiment_name']

[haraken, 2015/12/31 12:47:22]

Do we need this change?

[Daniel Nishi, 2016/01/04 18:56:31]

This is needed so that the check_api_experiment's code is generated for
constructors.

     # 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']