bindings: Make some value iterator properties aliases to Array.prototype functions

third_party/WebKit/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 337 matching lines @@
             elif child_class == 'Setlike':
                 self.setlike = IdlSetlike(child)
             else:
                 raise ValueError('Unrecognized node class: %s' % child_class)
 
         if len(filter(None, [self.iterable, self.maplike, self.setlike])) > 1:
             raise ValueError('Interface can only have one of iterable<>, maplike<> and setlike<>.')
 
         if has_integer_typed_length and has_indexed_property_getter:
             self.has_indexed_elements = True
+        else:
+            if self.iterable is not None and self.iterable.key_type is None:
+                raise ValueError('Value iterators (iterable<V>) must be accompanied by an indexed '
+                                 'property getter and an integer-typed length attribute.')
 
     def accept(self, visitor):
         visitor.visit_interface(self)
         for attribute in self.attributes:
             attribute.accept(visitor)
         for constant in self.constants:
             constant.accept(visitor)
         for constructor in self.constructors:
             constructor.accept(visitor)
         for custom_constructor in self.custom_constructors:
@@ skipping 743 matching lines @@
         self.visit_typed_object(argument)
 
     def visit_iterable(self, iterable):
         self.visit_typed_object(iterable)
 
     def visit_maplike(self, maplike):
         self.visit_typed_object(maplike)
 
     def visit_setlike(self, setlike):
         self.visit_typed_object(setlike)