def ext_class_name(interface):
    return ext_types.ext_type(interface.name)
def ext_class_name(interface):
    return ext_types.ext_type(interface.name)
def interface_context(interface):
    includes.clear()
    includes.update(INTERFACE_CPP_INCLUDES)
    header_includes = set(INTERFACE_H_INCLUDES)

    parent_interface = interface.parent
    if parent_interface:
        header_includes.update(ext_types.includes_for_interface(parent_interface))
    extended_attributes = interface.extended_attributes

    is_audio_buffer = inherits_interface(interface.name, 'AudioBuffer')
    if is_audio_buffer:
        includes.add('modules/webaudio/AudioBuffer.h')

    is_document = inherits_interface(interface.name, 'Document')
    if is_document:
        includes.update(['bindings/core/v8/ScriptController.h',
                         'bindings/core/v8/WindowProxy.h',
                         'core/frame/LocalFrame.h'])

    # [ActiveDOMObject]
    is_active_dom_object = 'ActiveDOMObject' in extended_attributes

    # [CheckSecurity]
    is_check_security = 'CheckSecurity' in extended_attributes
    if is_check_security:
        includes.add('bindings/core/v8/BindingSecurity.h')

    # [DependentLifetime]
    is_dependent_lifetime = 'DependentLifetime' in extended_attributes

    # [Iterable]
    iterator_method = None
    if 'Iterable' in extended_attributes:
        iterator_operation = IdlOperation(interface.idl_name)
        iterator_operation.name = 'iterator'
        iterator_operation.idl_type = IdlType('Iterator')
        iterator_operation.extended_attributes['RaisesException'] = None
        iterator_operation.extended_attributes['CallWith'] = 'ScriptState'
        iterator_method = ext_methods.method_context(interface,
                                                    iterator_operation)

    # [MeasureAs]
    is_measure_as = 'MeasureAs' in extended_attributes
    if is_measure_as:
        includes.add('core/frame/UseCounter.h')

    # [SetWrapperReferenceFrom]
    reachable_node_function = extended_attributes.get('SetWrapperReferenceFrom')
    if reachable_node_function:
        includes.update(['bindings/core/v8/V8GCController.h',
                         'core/dom/Element.h'])

    # [SetWrapperReferenceTo]
    set_wrapper_reference_to_list = [{
        'name': argument.name,
        # FIXME: properly should be:
        # 'cpp_type': argument.idl_type.cpp_type_args(raw_type=True),
        # (if type is non-wrapper type like NodeFilter, normally RefPtr)
        # Raw pointers faster though, and NodeFilter hacky anyway.
        'cpp_type': argument.idl_type.implemented_as + '*',
        'idl_type': argument.idl_type,
        'ext_type': ext_types.ext_type(argument.idl_type.name),
    } for argument in extended_attributes.get('SetWrapperReferenceTo', [])]
    for set_wrapper_reference_to in set_wrapper_reference_to_list:
        set_wrapper_reference_to['idl_type'].add_includes_for_type()

    # [NotScriptWrappable]
    is_script_wrappable = 'NotScriptWrappable' not in extended_attributes

    # [SpecialWrapFor]
    if 'SpecialWrapFor' in extended_attributes:
        special_wrap_for = extended_attribute_value_as_list(interface, 'SpecialWrapFor')
    else:
        special_wrap_for = []
    for special_wrap_interface in special_wrap_for:
        ext_types.add_includes_for_interface(special_wrap_interface)

    # [Custom=Wrap], [SetWrapperReferenceFrom]
    has_visit_dom_wrapper = (
        has_extended_attribute_value(interface, 'Custom', 'VisitDOMWrapper') or
        reachable_node_function or
        set_wrapper_reference_to_list)

    this_gc_type = gc_type(interface)

    wrapper_class_id = ('NodeClassId' if inherits_interface(interface.name, 'Node') else 'ObjectClassId')

    context = {
        'conditional_string': conditional_string(interface),  # [Conditional]
        'cpp_class': cpp_name(interface),
        'gc_type': this_gc_type,
        # FIXME: Remove 'EventTarget' special handling, http://crbug.com/383699
        'has_access_check_callbacks': (is_check_security and
                                       interface.name != 'Window' and
                                       interface.name != 'EventTarget'),
        'has_custom_legacy_call_as_function': has_extended_attribute_value(interface, 'Custom', 'LegacyCallAsFunction'),  # [Custom=LegacyCallAsFunction]
        'has_custom_to_v8': has_extended_attribute_value(interface, 'Custom', 'ToV8'),  # [Custom=ToV8]
        'has_custom_wrap': has_extended_attribute_value(interface, 'Custom', 'Wrap'),  # [Custom=Wrap]
        'has_visit_dom_wrapper': has_visit_dom_wrapper,
        'header_includes': header_includes,
        'interface_name': interface.name,
        'is_active_dom_object': is_active_dom_object,
        'is_audio_buffer': is_audio_buffer,
        'is_check_security': is_check_security,
        'is_dependent_lifetime': is_dependent_lifetime,
        'is_document': is_document,
        'is_event_target': inherits_interface(interface.name, 'EventTarget'),
        'is_exception': interface.is_exception,
        'is_node': inherits_interface(interface.name, 'Node'),
        'is_script_wrappable': is_script_wrappable,
        'iterator_method': iterator_method,
        'lifetime': 'Dependent'
            if (has_visit_dom_wrapper or
                is_active_dom_object or
                is_dependent_lifetime)
            else 'Independent',
        'measure_as': ext_utilities.measure_as(interface),  # [MeasureAs]
        'parent_interface': parent_interface,
        'pass_cpp_type': cpp_template_type(
            cpp_ptr_type('PassRefPtr', 'RawPtr', this_gc_type),
            cpp_name(interface)),
        'reachable_node_function': reachable_node_function,
        'runtime_enabled_function': runtime_enabled_function_name(interface),  # [RuntimeEnabled]
        'set_wrapper_reference_to_list': set_wrapper_reference_to_list,
        'special_wrap_for': special_wrap_for,
        'ext_class': ext_utilities.ext_class_name(interface),
        'wrapper_class_id': wrapper_class_id,
    }

    # Constructors
    constructors = [constructor_context(interface, constructor)
                    for constructor in interface.constructors
                    # FIXME: shouldn't put named constructors with constructors
                    # (currently needed for Perl compatibility)
                    # Handle named constructors separately
                    if constructor.name == 'Constructor']
    if len(constructors) > 1:
        context['constructor_overloads'] = overloads_context(constructors)

    # [CustomConstructor]
    custom_constructors = [{  # Only needed for computing interface length
        'number_of_required_arguments':
            number_of_required_arguments(constructor),
    } for constructor in interface.custom_constructors]

    # [EventConstructor]
    has_event_constructor = 'EventConstructor' in extended_attributes
    any_type_attributes = [attribute for attribute in interface.attributes
                           if attribute.idl_type.name == 'Any']
    if has_event_constructor:
        includes.add('bindings/core/v8/Dictionary.h')
        if any_type_attributes:
            includes.add('bindings/core/v8/SerializedScriptValue.h')

    # [NamedConstructor]
    named_constructor = named_constructor_context(interface)

    if (constructors or custom_constructors or has_event_constructor or
        named_constructor):
        includes.add('bindings/core/v8/V8ObjectConstructor.h')
        includes.add('core/frame/LocalDOMWindow.h')

    context.update({
        'any_type_attributes': any_type_attributes,
        'constructors': constructors,
        'has_custom_constructor': bool(custom_constructors),
        'has_event_constructor': has_event_constructor,
        'interface_length':
            interface_length(interface, constructors + custom_constructors),
        'is_constructor_raises_exception': extended_attributes.get('RaisesException') == 'Constructor',  # [RaisesException=Constructor]
        'named_constructor': named_constructor,
    })

    constants = [constant_context(constant) for constant in interface.constants]

    # Constants
    context.update({
        'constants': constants,
        'do_not_check_constants': 'DoNotCheckConstants' in extended_attributes,
        'has_constant_configuration': any(
            not constant['runtime_enabled_function']
            for constant in constants),
    })

    # Attributes
    attributes = [ext_attributes.attribute_context(interface, attribute)
                  for attribute in interface.attributes]
    context.update({
        'attributes': attributes,
        'has_accessors': any(attribute['is_expose_js_accessors'] and attribute['should_be_exposed_to_script'] for attribute in attributes),
        'has_attribute_configuration': any(
             not (attribute['is_expose_js_accessors'] or
                  attribute['is_static'] or
                  attribute['runtime_enabled_function'] or
                  attribute['per_context_enabled_function'])
             and attribute['should_be_exposed_to_script']
             for attribute in attributes),
        'has_conditional_attributes': any(attribute['per_context_enabled_function'] or attribute['exposed_test'] for attribute in attributes),
        'has_constructor_attributes': any(attribute['constructor_type'] for attribute in attributes),
        'has_replaceable_attributes': any(attribute['is_replaceable'] for attribute in attributes),
    })

    # Methods
    methods = [ext_methods.method_context(interface, method)
               for method in interface.operations
               if method.name]  # Skip anonymous special operations (methods)
    compute_method_overloads_context(methods)

    # Stringifier
    if interface.stringifier:
        stringifier = interface.stringifier
        method = IdlOperation(interface.idl_name)
        method.name = 'toString'
        method.idl_type = IdlType('DOMString')
        method.extended_attributes.update(stringifier.extended_attributes)
        if stringifier.attribute:
            method.extended_attributes['ImplementedAs'] = stringifier.attribute.name
        elif stringifier.operation:
            method.extended_attributes['ImplementedAs'] = stringifier.operation.name
        methods.append(ext_methods.method_context(interface, method))

    conditionally_enabled_methods = []
    custom_registration_methods = []
    method_configuration_methods = []

    for method in methods:
        # Skip all but one method in each set of overloaded methods.
        if 'overload_index' in method and 'overloads' not in method:
            continue

        if 'overloads' in method:
            overloads = method['overloads']
            per_context_enabled_function = overloads['per_context_enabled_function_all']
            conditionally_exposed_function = overloads['exposed_test_all']
            runtime_enabled_function = overloads['runtime_enabled_function_all']
            has_custom_registration = overloads['has_custom_registration_all']
        else:
            per_context_enabled_function = method['per_context_enabled_function']
            conditionally_exposed_function = method['exposed_test']
            runtime_enabled_function = method['runtime_enabled_function']
            has_custom_registration = method['has_custom_registration']

        if per_context_enabled_function or conditionally_exposed_function:
            conditionally_enabled_methods.append(method)
            continue
        if runtime_enabled_function or has_custom_registration:
            custom_registration_methods.append(method)
            continue
        if method['should_be_exposed_to_script']:
            method_configuration_methods.append(method)

    for method in methods:
        # The value of the Function object’s “length” property is a Number
        # determined as follows:
        # 1. Let S be the effective overload set for regular operations (if the
        # operation is a regular operation) or for static operations (if the
        # operation is a static operation) with identifier id on interface I and
        # with argument count 0.
        # 2. Return the length of the shortest argument list of the entries in S.
        # FIXME: This calculation doesn't take into account whether runtime
        # enabled overloads are actually enabled, so length may be incorrect.
        # E.g., [RuntimeEnabled=Foo] void f(); void f(long x);
        # should have length 1 if Foo is not enabled, but length 0 if it is.
        method['length'] = (method['overloads']['minarg'] if 'overloads' in method else
                            method['number_of_required_arguments'])

    context.update({
        'conditionally_enabled_methods': conditionally_enabled_methods,
        'custom_registration_methods': custom_registration_methods,
        'has_origin_safe_method_setter': any(
            method['is_check_security_for_frame'] and not method['is_read_only']
            for method in methods),
        'has_private_script': any(attribute['is_implemented_in_private_script'] for attribute in attributes) or
            any(method['is_implemented_in_private_script'] for method in methods),
        'method_configuration_methods': method_configuration_methods,
        'methods': methods,
    })

    context.update({
        'indexed_property_getter': indexed_property_getter(interface),
        'indexed_property_setter': indexed_property_setter(interface),
        'indexed_property_deleter': indexed_property_deleter(interface),
        'is_override_builtins': 'OverrideBuiltins' in extended_attributes,
        'named_property_getter': named_property_getter(interface),
        'named_property_setter': named_property_setter(interface),
        'named_property_deleter': named_property_deleter(interface),
    })

    return context