[bindings] Include V8HiddenValue only if attribute has CachedAttribute or marked keep alive for GC.

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 69 matching lines @@
     is_only_exposed_to_private_script = 'OnlyExposedToPrivateScript' in extended_attributes
     # [PerWorldBindings]
     if 'PerWorldBindings' in extended_attributes:
         assert idl_type.is_wrapper_type or 'LogActivity' in extended_attributes, '[PerWorldBindings] should only be used with wrapper types: %s.%s' % (interface.name, attribute.name)
 
     if (base_idl_type == 'EventHandler' and
         interface.name in ['Window', 'WorkerGlobalScope'] and
         attribute.name == 'onerror'):
         includes.add('bindings/core/v8/V8ErrorHandler.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')
+
     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]
         'argument_cpp_type': idl_type.cpp_type_args(used_as_rvalue_type=True),
-        'cached_attribute_validation_method': extended_attributes.get('CachedAttribute'),
+        'cached_attribute_validation_method': cached_attribute_validation_method,
         'conditional_string': v8_utilities.conditional_string(attribute),
         'constructor_type': idl_type.constructor_type_name
                             if is_constructor_attribute(attribute) else None,
         '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_validation_expression': idl_type.enum_validation_expression,
         '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_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_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_initialized_by_event_constructor':
             'InitializedByEventConstructor' in extended_attributes,
-        'is_keep_alive_for_gc': is_keep_alive_for_gc(interface, attribute),
+        'is_keep_alive_for_gc': keep_alive_for_gc,
         '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 395 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']