IDL: Prefer to extend IdlTypeBase instead of IdlType

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 10 matching lines @@
 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 """Generate template values for methods.
 
-Extends IdlType and IdlUnionType with property |union_arguments|.
+Extends IdlArgument with property |default_cpp_value|.
+Extends IdlTypeBase and IdlUnionType with property |union_arguments|.
 
 Design doc: http://www.chromium.org/developers/design-documents/idl-compiler
 """
 
 from idl_definitions import IdlArgument
-from idl_types import IdlType, IdlUnionType, inherits_interface
+from idl_types import IdlTypeBase, IdlUnionType, inherits_interface
 from v8_globals import includes
 import v8_types
 import v8_utilities
 from v8_utilities import has_extended_attribute_value
 
 
 # Methods with any of these require custom method registration code in the
 # interface's configure*Template() function.
 CUSTOM_REGISTRATION_EXTENDED_ATTRIBUTES = frozenset([
     'DoNotCheckSecurity',
@@ skipping 357 matching lines @@
     return [arg
             for i in range(len(idl_type.member_types))
             for arg in ['result%sEnabled' % i, 'result%s' % i]]
 
 
 def argument_default_cpp_value(argument):
     if not argument.default_value:
         return None
     return argument.idl_type.literal_cpp_value(argument.default_value)
 
-IdlType.union_arguments = property(lambda self: None)
+IdlTypeBase.union_arguments = None
 IdlUnionType.union_arguments = property(union_arguments)
 IdlArgument.default_cpp_value = property(argument_default_cpp_value)