Preparation of Promise<T> support in the Web IDL parser

Source/bindings/scripts/idl_definitions.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 771 matching lines @@
     if node_class in ['PrimitiveType', 'Typeref']:
         # unrestricted syntax: unrestricted double | unrestricted float
         is_unrestricted = node.GetProperty('UNRESTRICTED') or False
         return IdlType(node.GetName(), is_unrestricted=is_unrestricted)
     elif node_class == 'Any':
         return IdlType('any')
     elif node_class == 'Sequence':
         return sequence_node_to_type(node)
     elif node_class == 'UnionType':
         return union_type_node_to_idl_union_type(node)
+    elif node_class == 'Promise':
+        return IdlType('Promise')
     raise ValueError('Unrecognized node class: %s' % node_class)
 
 
 def sequence_node_to_type(node):
     children = node.GetChildren()
     if len(children) != 1:
         raise ValueError('Sequence node expects exactly 1 child, got %s' % len(children))
     sequence_child = children[0]
     sequence_child_class = sequence_child.GetClass()
     if sequence_child_class != 'Type':
@@ skipping 13 matching lines @@
     child_class = child.GetClass()
     if child_class != 'Type':
         raise ValueError('Unrecognized node class: %s' % child_class)
     return type_node_to_type(child)
 
 
 def union_type_node_to_idl_union_type(node):
     member_types = [type_node_to_type(member_type_node)
                     for member_type_node in node.GetChildren()]
     return IdlUnionType(member_types)