IDL: Fix handling of nullable NodeFilter / XPathNSResolver arguments

Source/bindings/scripts/v8_methods.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 205 matching lines @@
     def cpp_argument(argument):
         idl_type = argument.idl_type
         if idl_type.name == 'EventListener':
             if (interface.name == 'EventTarget' and
                 method.name == 'removeEventListener'):
                 # FIXME: remove this special case by moving get() into
                 # EventTarget::removeEventListener
                 return '%s.get()' % argument.name
             return argument.name
         if (idl_type.is_callback_interface or
-            idl_type.name in ['NodeFilter', 'XPathNSResolver']):
+            idl_type.name in ['NodeFilter', 'NodeFilterOrNull',

[Jens Widell, 2014/06/25 14:01:02]

For both NodeFilter and XPathNSResolver, the local variable will be of type
RefPtrWillBeRawPtr<X> and the argument will be of type
PassRefPtrWillBeRawPtr<X>. If I read RefPtr<>/PassRefPtr<> correctly, the
difference would be that the local holds on to a reference until it goes out of
scope without ".release()", and that's it. Should we just drop the special
casing?

With Oilpan and actual raw pointers, we will want to get rid of ".release()"
anyway, and then the effect will be that the local keeps the object alive until
it goes out of scope (at least.)

Note: is_callback_interface still needs the special casing, since it's sometimes
OwnPtr<>, where we certainly need to release.

+                              'XPathNSResolver', 'XPathNSResolverOrNull']):
             # FIXME: remove this special case
             return '%s.release()' % argument.name
         return argument.name
 
     # Truncate omitted optional arguments
     arguments = method.arguments[:number_of_arguments]
     cpp_arguments = []
     if method.is_constructor:
         call_with_values = interface.extended_attributes.get('ConstructorCallWith')
     else:
@@ skipping 86 matching lines @@
 
 
 def union_arguments(idl_type):
     """Return list of ['result0Enabled', 'result0', 'result1Enabled', ...] for union types, for use in setting return value"""
     return [arg
             for i in range(len(idl_type.member_types))
             for arg in ['result%sEnabled' % i, 'result%s' % i]]
 
 IdlType.union_arguments = property(lambda self: None)
 IdlUnionType.union_arguments = property(union_arguments)